2023 Best Testosterone Supplement Stack & Testosterone Boosting Diet
By Steve Blechman
A study published June 1st, 2022 in the prestigious journal The Lancet Healthy Longevity “found no evidence that testosterone increased long-term to medium-term cardiovascular risk in men with hypogonadism.” The study was a most in-depth “meta-analysis of more than 3,000 patients with hypogonadism from randomized placebo-controlled trials done by 17 research groups.” 1,750 patients received testosterone and 1,681 were given a placebo for about 9.5 months.
The researchers found that “testosterone treatment did not have adverse effects on blood pressure or glycemic markers compared to placebo; furthermore, it did not increase thrombotic events despite increased haematocrit. Testosterone treatment was associated with a modest lowering of total HDL cholesterol and triglyceride concentration compared with placebo.” Currently, a long-term 5-year testosterone clinical trial is being investigated in 5,000 men.
A study published March 2022 in the journal Endocrinology & Metabolism Clinics of North America reported that “middle-aged and older men with lower testosterone concentrations are more likely to have or to develop metabolic syndrome and type 2 diabetes. Central adiposity is risk factor from metabolic syndrome and diabetes and predisposed to lower testosterone concentrations. Conversely, testosterone treatment reduces fat mass and insulin resistance. In a randomized control trial of 1,007 men with either impaired glucose tolerance or newly diagnosed type 2 diabetes, two years of testosterone treatment on a background of lifestyle intervention reduced the risk of type 2 diabetes by 40%; this demonstrates the potential utility for testosterone pharmacology to prevent diabetes in men,” according to the researchers.
A study published January 2022 in the journal Andrology reported that “circulating testosterone levels have been found to be reduced in men with severe acute respiratory syndrome coronavirus 2 infection, COVID-19, with lower levels being associated with more severe clinical outcomes.”
In a seven-month cohort study in males with COVID-19, “testosterone levels increased over time after COVID-19, more than 50% of men who recovered from the disease still had circulated testosterone levels suggested for a condition of hypogonadism at seven-month follow up. In as many as 10% of cases, testosterone levels even further decreased.”
Recently, “Decreased serum testosterone levels have been reported to be caused by obstructive sleep apnea (OSA). A new study published July 29th, 2022 further confirmed that OSA is “significantly correlated with the decrease in serum testosterone levels in men.” The researchers “performed a meta-analysis to assess the association between OSA and serum testosterone levels.”
The meta-analysis “included 24 case-control studies with 1,389 patients (1,268 male patients) and 845 controls (745 male control). The serum testosterone levels in the male OSA group were significantly lower than the control group.” The researchers said that “male patients with OSA should be alerted to secondary diseases caused by low testosterone.”
A study published June 2022 in the journal Endocrine Connections, reported that a random population sample of 1,400 men in Sweden that high C-reactive protein (CRP) was associated with lower “bioavailable testosterone and increased risk of biochemical hypogonadism.” CRP is the measure of systemic inflammation. It is produced in the liver and released in response to inflammation in the body. A simple blood test can measure CRP and inflammation in the body. The researchers acknowledge we need to “better understand the possible impact of inflammation on sexual hormonal secretion and male health.”
Certain weight-loss diets can lower testosterone. The journal Nutrition and Health reported on March 7, 2022 a meta-analysis of 27 studies including 309 participants who reported that a low carbohydrate and “high in protein diets cause a large decrease in resting testosterone.”
It was also reported in the journal Nutrients on June 3rd, 2022 that “intermittent fasting reduced testosterone levels in lean, physically active, young males.” The researchers said “fasting men may be shown to decrease androgens among males, which could negatively affect metabolic health and libido. More research is warranted to confirm these preliminary findings.”
THE BEST TESTOSTERONE BOOSTING DIET
When it comes to diet, low-fat diets lower testosterone levels. Saturated and monounsaturated fatty acids have been shown to directly and systematically boost testosterone while polyunsaturated fats, by and large, inhibit testosterone production. Arachidonic acid, an omega-6 derived polyunsaturated fatty acid, does support testosterone production, but I do not recommend it as a dietary supplement because it is a substrate for the inflammatory cascade and inflammation in the body. You get all the arachidonic acid you need from the diet. No need to take supplemental arachidonic acid, as it may increase inflammation and the risk of heart disease and other degenerative diseases. The best and healthiest fats for boosting testosterone are monounsaturated fats, which are found preferably in extra-virgin olive oil, avocados and nuts. Not saturated fats, which can increase the risk of cardiovascular disease. Nuts are high in zinc and magnesium. Diets deficient in zinc can lower testosterone levels. Zinc supplements have also been shown to increase testosterone in zinc-deficient adults. Also, oral zinc supplements increase total and free testosterone levels in elite athletes after exhaustion exercise. Also, low vitamin D is linked to low testosterone.
Coffee is also good for boosting testosterone. A Harvard University study led by Nicole Wedick showed that men who drink caffeinated coffee show increases in total testosterone and decreases in free estradiol (estrogen). Coffee is loaded with phenolic antioxidants that act as natural aromatase inhibitors, which prevent the conversion of testosterone to estrogen (Nutrition Journal, 2012). Among men, consumption of caffeinated coffee has been shown to raise testosterone levels and decrease total estrogen and estradiol levels.
So, if you want to boost testosterone and enhance fat loss, follow the Mediterranean diet. A study published in JAMA on April 25, 2018 found that the Mediterranean diet fights against frailty. It’s just another study that supports the Mediterranean diet to preserve lean body mass and health during aging. It’s also especially important to follow a high-intensity resistance training program for maintaining testosterone and enhancing lean body mass. Don’t overdo long periods of cardiovascular, aerobic exercise as it can lower testosterone and encourage overtraining. Overtraining can lower testosterone and raise cortisol. Rest and recovery are important in maintaining normal, healthy testosterone levels.
BEST NATURAL TESTOSTERONE SUPPLEMENT STACK & BOOSTERS
DHEA is a naturally occurring steroid hormone in the body that can enhance health, vitality, fat loss and improve “free testosterone” levels (the most important kind!) when taken before high-intensity exercise.
DHEA is a prohormone, serving as a precursor to testosterone, which has sparked interest as a potential “Fountain of Youth” supplement. However, just like testosterone, DHEA levels peak in early adulthood and then slowly fall as you age. To combat the effects of aging and declining DHEA, many adults supplement with DHEA.
Low levels of DHEA have been shown to increase storage of abdominal fat! The good news is that supplementing with 50 mg of DHEA per day prevented abdominal fat and improved insulin action, meaning DHEA replacement could play a significant role in the prevention and treatment of the metabolic syndrome. But there’s more.
Additional research into DHEA concluded that it can inhibit fat cell growth, increase metabolic rate and lower cortisol, the catabolic stress hormone that also suppresses brown fat tissue function in humans, lowering energy expenditure and enhancing abdominal fat storage. The exact opposite of what you want when trying to reshape your body.
DHEA can combat cortisol, boost free testosterone and help prevent muscle loss and overtraining. 50 mg of DHEA before exercise can improve free testosterone levels and improve testosterone/cortisol ratio. But here’s the really cool thing about DHEA …
DHEA can increase free testosterone after exercise!
There are two types of testosterone in the body: free testosterone and bound testosterone. Free testosterone is the most biologically active form of testosterone, while bound testosterone is biologically inactive, due to sex hormone-binding globulin (SHBG). In order for your body to use testosterone, it must unbind the testosterone, making it free and usable. DHEA can do this!
High-intensity interval training (HIIT) increases fitness rapidly but suppresses testosterone, which could increase the susceptibility to overtraining. But, research notes that DHEA supplemented at 50 mg was found to increase circulating DHEA and free testosterone above baseline AND prevented those levels from declining during HIIT. More importantly, this study also showed that oral DHEA supplements can elevate free testosterone!
Another study found that 50 mg of oral DHEA given to men aged 40 to 70 for three months saw an increase in androstenedione (another important anabolic hormone) and a significant increase in the anabolic hormone IGF-1! Moreover, there was no change in circulating levels of sex hormone-binding globulin, estrogen (estrone or estradiol).
Also, more isn’t better when it comes to DHEA, as research shows that taking amounts higher than 50 mg does not provide more effective results and may potentially predispose you to unwanted side effects.
Boron is an ultra-trace element found in humans first introduced in the 1980s as a testosterone booster. Studies reported that when dosed at 10 mg per day, boron increased testosterone. One study in particular showed that 10 mg of boron per day for seven days increased free testosterone by 28% and decreased estrogen levels by 39%. Another study in the Journal of Trace Elements Medicine and Biology reported that supplementing 10 mg of boron per day in healthy young males (ages 29 to 50) for a week decreased levels of sex hormone-binding globulin (SHBG) and significantly increased levels of free testosterone, which makes the hormone more biologically active.
Remember, in order for the body to use testosterone it must unbind the testosterone, making it free and usable. Boron does this by blocking the sex hormone-binding globulin (SHBG) from binding testosterone, making it unusable by the body.
Additional benefits of boron include decreased biomarkers of inflammation, such as c-reactive proteins (CRP). Lowering the level of CRP has been shown to enhance cardiovascular health.
FENUGREEK SEED EXTRACT
A staple of Ayurveda, fenugreek has a long history of use in traditional medicine. Studies have shown that fenugreek has blood sugar- and cholesterol-lowering properties, and may also improve insulin function and sensitivity, due to the presence of the amino acid 4-hydroxyisoleucine.
The powerful plant also contains glycosides and steroidal saponins that can boost free testosterone and inhibit aromatase. It should be noted that a portion of testosterone is converted to estrogen through a process called aromatization, which increases estrogen levels and decreases testosterone; however, aromatase inhibitors (like fenugreek) prevent the conversion of testosterone to estrogen, thereby reducing estrogen levels and increasing testosterone.
Given the potency of aromatase inhibitors, they’re a favorite for bodybuilders looking to prevent gynecomastia – the development of female-like breast tissue. But many of the pharmaceuticals come with a range of unwanted side effects, putting your health and well-being at risk. Fenugreek is a natural aromatase inhibitor shown to be safe in research trials.
Research published in the International Journal Sports Nutrition Exercise Metabolism (2010) noted that fenugreek supplementation decreased body fat and increased total and biologically available testosterone (compared to a placebo). Subjects in the trial trained four days per week consuming 500 mg of a standardized fenugreek extract.
After the trial, researchers concluded fenugreek “incompletely inhibited aromatase and 5-alpha-reductase activity while significantly increasing total and bioavailable testosterone levels, as well as decreasing percent body fat in conjunction with a resistance-training program.”
A study published in the Journal of Sports and Health Science (2015) reported that an eight-week treatment containing a standardized fenugreek extract (600 mg daily) offered beneficial effects in terms of repetition to failure in leg press and increased free testosterone levels compared to placebo, and it demonstrated significant anabolic and androgenic activity as compared with placebo. Subjects experienced significant improvements in body fat without a reduction in muscle strength or repetitions to failure. Best of all, supplementation with fenugreek came without any clinical side effects.
In short, fenugreek enhances testosterone levels, decreases estrogen levels, improves body composition and comes with absolutely no drawbacks!
Tongkat ali (aka longjack) is a Malaysian plant used throughout Asia as an aphrodisiac. It’s extracted from the root of the small tree Eurycoma longifolia, which is typically consumed as a beverage in Southeast Asia.
A study from the National Research Institute of Scientific Medicine found that tongkat ali promoted erection and delayed ejaculations in rats. Researchers determined that tongkat ali promoted penile blood flow while reducing stimulation of smooth muscle in the penis – which enhanced erections without overstimulation that would lead to premature ejaculation, suggesting that longjack might help men with two of the most common sexual disabilities: erectile dysfunction and premature ejaculation (Journal of Sexual Medicine, May 2011)
Tongkat ali has been shown to increase testosterone concentrations, muscle mass and strength in men and women. Studies in humans have demonstrated that 100 mg of tongkat ali extract increased strength and muscle circumference while treatment with 200 mg and 400 mg of tongkat ali increased total and free testosterone concentration.
Additionally, tongkat ali is often referred to as “Malaysian ginseng” for its adaptogenic benefits where it exerts anti-stress properties and restores hormonal balance by improving testosterone to cortisol ratio. Tongkat ali extract also increases free testosterone by inhibiting sex hormone-binding globulin (SHBG), and research demonstrates that supplementation with tongkat ali root extract (200 mg/day) improves stress hormone profile (lower cortisol, higher testosterone) as a result of stresses such as dieting for weight loss, sleep deprivation and intense exercise training.
In two other studies, tongkat ali supplementation (100 mg/day) improved lean body mass, one-repetition maximum (1RM) strength and arm circumference to a significantly greater degree compared to placebo.
In men with low testosterone (average age 51), one month of daily supplementation with tongkat ali extract (200 mg/day) resulted in significantly improved serum testosterone levels, and another study using young healthy adult males (average age 25) demonstrated that 100 mg/day of tongkat ali extract, added to an intense strength-training program, improved lean body mass and arm size compared to placebo group. The results demonstrate that tongkat ali extract can enhance muscle mass and strength and enhance fat loss in healthy exercises.
Additional studies showed that 50-100 mg/day of tongkat ali extract helped improve normal testosterone levels in supplemental dieters (compared to a drop in testosterone among non-supplemental dieters). For many dieters, it would be expected for cortisol to rise and testosterone to fall following several weeks of dieting. Also, in one trial, endurance cyclists’ cortisol levels were 32% lower and testosterone levels were 16% higher in supplemental subjects compared to placebo, creating an anabolic state.
Basically, tongkat ali is a very effective compound that has been shown to increase total and free testosterone concentrations, muscle mass and strength in men!
A newer study was reported in the journal Medicina on August 4, 2022, a “systematic review and meta-analysis of the literature supports the possible use of E. longifolia supplementation for enhancing testosterone production.” This study and metal-analysis reported a “significant improvement in total testosterone levels after E. longifolia treatment,” in both healthy and hypogonadal men.
RED WINE POLYPHENOLS
Red wine is a rich source of polyphenols, bioflavonoids that serve as potent antioxidants. Studies have shown that red wine polyphenols may help promote cardiovascular health.
The polyphenols, anthocyanins and procyanidins in red wine provide the most cardiovascular health benefits. One of the most popular polyphenols is resveratrol, which also has many health benefits, and a big reason behind the push to consume red wine these days. However, we currently don’t know which polyphenols are best, so, it’s good to take a mixture found in red wine.
Research studies have shown that red wine polyphenols are potent, natural aromatase inhibitors that decrease estrogen and increase testosterone levels. They’re also potent nitric oxide boosters that enhance vasodilation and blood flow, meaning they’re great for getting a muscle pump!
Red wine polyphenols can also raise free testosterone by reducing sex hormone-binding globulin (SHBG), a carrier protein that protects testosterone from being metabolized while in the bloodstream.
Additionally, researchers found that red wine polyphenols might reduce the amount of testosterone excreted by the body, leading researchers to believe that if further studied, it’s possible that the “compounds in red wine can reduce the amount of testosterone in urine and give a boost to testosterone levels.”
Low levels of vitamin D are linked to low blood testosterone. An Austrian study showed that supplementation with vitamin D (3,332 IU) daily in men for one year increased testosterone by 20% and the biologically active free testosterone by 17% via lowering sex hormone-binding globulin (SHBG). Vitamin D also decreases the breakdown of testosterone into estrogen by reducing the expression of the aromatase enzyme, and has been shown to raise IGF-1 levels.
Vitamin D is produced by the body via exposure sunlight and through the diet. It is critical for bone health but also important for immune system function. The increased incidence of colds and flu during the winter may be due to reduced levels of vitamin D.
Vitamin D can also increase muscle strength. A review of vitamin D concluded that supplementation with the vitamin (4,000 IU per day) increased upper and lower strength. The review included 310 adults, average age 21 to 31. The authors wrote, “This review has found that vitamin D3 supplementation improves upper and lower muscle strength in a healthy adult, athletic and non-athletic population between ages of 18 and 40.” This was the first finding that vitamin D can increase muscle strength in young, healthy adults.
As if that wasn’t reason enough to use vitamin D, consider this: Vitamin D supplementation can also cut body fat!
Vitamin D supplements combined with 12 weeks of weight training improved and increased power output in overweight young adults – according to a study led by Andres Carrillo from Purdue University. Researchers supplemented 4,000 IU of vitamin D per day. They found improvements in peak power output and waist-to-hip ratio.
WHAT WORKS AND WHAT DOESN’T
Why have so many supplement companies jumped on the Fadogia agrestis hype?
Fadogia agrestis is a very popular testosterone-boosting dietary supplement. Unfortunately, “there are no clinical studies in humans. There are grand total of six studies on Fadogia agrestis (with only one investigating testosterone) and those are conducted in rats.” “Furthermore, all the research on Fadogia agrestis to date, as well as those work cited in other reviews, is from the same team of investigators. In other words, there has yet to be any confirmation on the effects of Fadogia agrestis extract on testosterone by other research laboratories!” “We simply don't have enough quality data to be sure of the efficacy or safety of Fadogia agrestis.” (Testosterone Booster Research Update: Fodagia Agrestisis: Is It the Real Deal? by Robert Schinetsky, September 13th, 2022)
Bottom line: there are no clinical studies or clinical tests on humans with Fadogia agrestis! Or studies in humans that it boosts testosterone!!
D-Aspartic acid, Tribulus terrestris, stinging nettle, saw palmetto, maca root extract, damiana leaf extract, indole 3-carbinol and 3,3-diindolylmethane (DIM) are not reviewed in the report because of lack of published, scientific human research supporting increased free or total testosterone in humans. Also, purified supplements of indole-3-carbinol and DIM are shown to be phytoestrogens, anti-androgens (blocking androgen receptors) and endocrine disruptors. They shouldn’t be taken as dietary supplements if you want to maximize testosterone function! If you want to get your health benefits from these compounds, then play it safe and eat your cruciferous vegetables such as broccoli, cauliflower, Brussels sprouts or asparagus.
For example, the latest research has shown that D-aspartic acid decreases testosterone! Australian scientists from the University of Western Sydney, led by Geoffrey Melville, found that daily supplementation of either 3 or 6 grams of D-aspartic acid decreased total and free testosterone in resistance-trained men and had no effect on related hormones such as estrogen or sex-hormone binding globulin (Nutrition Research, 2013 & Journal of the International Society of Sports Nutrition, 2015)
Another example is Tribulus terrestris, often recommended for increasing testosterone. Tribulus terrestris is an herb that was fist cultivated on the Steppes of Georgia (the country, not the state). East Bloc athletes used it to boost testosterone production and improve performance. Russian scientists theorized that the herb acts like the pituitary hormone (LH) to stimulate testosterone release in the testes. The supplement has been extremely popular with bodybuilders and powerlifters for increasing performance and non-athletic men for improving sexual performance, even though little research supports its effectiveness. Well-controlled studies have found that Tribulus has no effect on strength, body composition, or testosterone. (Journal of Human Kinetics, 2014)
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1. Hudson J, Cruickshank M, Quinton R, Aucott L, Aceves-Martins M, Gillies K, Bhasin S, Snyder PJ, Ellenberg SS, Grossmann M, Travison TG, Gianatti EJ, van der Schouw YT, Emmelot-Vonk MH, Giltay EJ, Hackett G, Ramachandran S, Svartberg J, Hildreth KL, Groti Antonic K, Brock GB, Tenover JL, Tan HM, Kong CHC, Tan WS, Marks LS, Ross RJ, Schwartz RS, Manson P, Roberts S, Andersen MS, Magnussen LV, Hernández R, Oliver N, Wu F, Dhillo WS, Bhattacharya S, Brazzelli M, Jayasena CN. Adverse cardiovascular events and mortality in men during testosterone treatment: an individual patient and aggregate data meta-analysis. Lancet Healthy Longev 2022 Jun;3(6):e381-e393. doi: 10.1016/S2666-7568(22)00096-4. PMID: 35711614; PMCID: PMC9184259
2. Little evidence testosterone treatment increases the risk of cardiovascular events, most in-depth analysis suggests by Lancet June 8, 2022. Medical Xpress https://medicalxpress.com/news/2022-06-evidence-testosterone-treatment-cardiovascular-events.html
3. Cienfuegos S, Corapi S, Gabel K, Ezpeleta M, Kalam F, Lin S, Pavlou V, Varady KA. Effect of Intermittent Fasting on Reproductive Hormone Levels in Females and Males: A Review of Human Trials. Nutrients 2022 Jun 3;14(11):2343. doi: 10.3390/nu14112343. PMID: 35684143; PMCID: PMC9182756.
4. Whittaker J, Harris M. Low-carbohydrate diets and men's cortisol and testosterone: Systematic review and meta-analysis. Nutr Health 2022 Mar 7:2601060221083079. doi: 10.1177/02601060221083079. Epub ahead of print. PMID: 35254136.
5. Wang H, Lu J, Xu L, Yang Y, Meng Y, Li Y, Liu B. Obstructive sleep apnea and serum total testosterone: a system review and meta-analysis. Sleep Breath 2022 Jul 29. doi: 10.1007/s11325-022-02655-6. Epub ahead of print. PMID: 35904664.
6. Wang H, Lu J, Xu L, Yang Y, Meng Y, Li Y, Liu B. Obstructive sleep apnea and serum total testosterone: a system review and meta-analysis. Sleep Breath 2022 Jul 29. doi: 10.1007/s11325-022-02655-6. Epub ahead of print. PMID: 35904664.
7. Yeap BB, Wittert GA. Testosterone, Diabetes Risk, and Diabetes Prevention in Men. Endocrinol Metab Clin North Am 2022 Mar;51(1):157-172. doi: 10.1016/j.ecl.2021.11.004. Epub 2022 Feb
8. PMID: 35216714. 8. Salonia A, Pontillo M, Capogrosso P, Gregori S, Carenzi C, Ferrara AM, Rowe I, Boeri L, Larcher A, Ramirez GA, Tresoldi C, Locatelli M, Cavalli G, Dagna L, Castagna A, Zangrillo A, Tresoldi M, Landoni G, Rovere-Querini P, Ciceri F, Montorsi F. Testosterone in males with COVID-19: A 7-month cohort study. Andrology 2022 Jan;10(1):34-41. doi: 10.1111/andr.13097. Epub 2021 Aug 31. PMID: 34409772; PMCID: PMC8444879.
9. Salonia A, Pontillo M, Capogrosso P, Gregori S, Carenzi C, Ferrara AM, Rowe I, Boeri L, Larcher A, Ramirez GA, Tresoldi C, Locatelli M, Cavalli G, Dagna L, Castagna A, Zangrillo A, Tresoldi M, Landoni G, Rovere-Querini P, Ciceri F, Montorsi F. Testosterone in males with COVID-19: A 7-month cohort study. Andrology 2022 Jan;10(1):34-41. doi: 10.1111/andr.13097. Epub 2021 Aug 31. PMID: 34409772; PMCID: PMC8444879.
10. Osmancevic A, Ottarsdottir K, Hellgren M, Lindblad U, Daka B. High C-reactive protein is associated with increased risk of biochemical hypogonadism: a population-based cohort study. Endocr Connect 2022 Jun 24;11(7):e220141. doi: 10.1530/EC-22-0141. PMID: 35904226; PMCID: PMC9254292.
11. Yftach Gepner, Ilan Shelef, Dan Schwarzfuchs, Hila Zelicha, Lilac Tene, Anat Yaskolka Meir, Gal Tsaban, Noa Cohen, Nitzan Bril, Michal Rein, Dana Serfaty, Shira Kenigsbuch, Oded Komy, Arik Wolak, Yoash Chassidim, Rachel Golan, Hilla Avni-Hassid, Avital Bilitzky, Benjamin Sarusi, Eyal Goshen, Elad Shemesh, Yaakov Henkin, Michael Stumvoll, Matthias Blüher, Joachim Thiery, Uta Ceglarek, Assaf Rudich, Meir J. Stampfer, Iris Shai. Effect of Distinct Lifestyle Interventions on Mobilization of Fat Storage Pools: The CENTRAL MRI Randomized Controlled Trial. Circulation 2017; CIRCULATIONAHA.117.030501 DOI: 10.1161/CIRCULATIONAHA.117.030501
12. Voelker R. The Mediterranean Diet’s Fight Against Frailty. JAMA 2018;319(19):1971-1972. doi:10.1001/jama.2018.3653
13. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. Iris Shai, R.D., Ph.D., Dan Schwarzfuchs, M.D., Yaakov Henkin, M.D., Danit R. Shahar, R.D., Ph.D., Shula Witkow, R.D., M.P.H., Ilana Greenberg, R.D., M.P.H., Rachel Golan, R.D., M.P.H., Drora Fraser, Ph.D., Arkady Bolotin, Ph.D., Hilel Vardi, M.Sc., Osnat Tangi-Rozental, B.A., Rachel Zuk-Ramot, R.N., Benjamin Sarusi, M.Sc., Dov Brickner, M.D., Ziva Schwartz, M.D., Einat Sheiner, M.D., Rachel Marko, M.Sc., Esther Katorza, M.Sc., Joachim Thiery, M.D., Georg Martin Fiedler, M.D., Matthias Blüher, M.D., Michael Stumvoll, M.D., and Meir J. Stampfer, M.D., Dr.P.H., for the Dietary Intervention Randomized Controlled Trial (DIRECT) Group. N Engl J Med 2008; 359:229-241July 17, 2008DOI: 10.1056/NEJMoa0708681
14. The effect of dietary oleic, linoleic, and linolenic acids on fat oxidation and energy expenditure in healthy men. Jones, Peter J.H. et al. Metabolism - Clinical and Experimental, Volume 57, Issue 9, 1198-1203
15. Nut intake and 5-year changes in body weight and obesity risk in adults: results from the EPIC-PANACEA study. European Journal of Nutrition 2017, Page 1 Heinz Freisling, Hwayoung Noh, Nadia Slimani.
16. Oleuropein, a Phenolic Compound in Extra Virgin Olive Oil, Increases Uncoupling Protein 1 Content in Brown Adipose Tissue and Enhances Noradrenaline and Adrenaline Secretions in Rats. Journal of Nutritional Science and Vitaminology, Released November 11, 2008 Yuriko Oi-Kano, Teruo Kawada, Tatsuo Watanabe, Fumihiro Koyama, Kenichi Watanabe, Reijirou Senbongi, Kazuo Iwai.
17. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. Ramón Estruch, M.D., Ph.D., Emilio Ros, M.D., Ph.D., Jordi Salas-Salvadó, M.D., Ph.D., Maria-Isabel Covas, D.Pharm., Ph.D., Dolores Corella, D.Pharm., Ph.D., Fernando Arós, M.D., Ph.D., Enrique Gómez-Gracia, M.D., Ph.D., Valentina Ruiz-Gutiérrez, Ph.D., Miquel Fiol, M.D., Ph.D., José Lapetra, M.D., Ph.D., Rosa M. Lamuela-Raventos, D.Pharm., Ph.D., Lluís Serra-Majem, M.D., Ph.D., et al., for the PREDIMED Study Investigators. New England Journal of Medicine (NEJM) June 13, 2018 https://www.nejm.org/doi/full/10.1056/NEJMoa1800389
18. Fungwe TV, et al. Stimulation of fatty acid biosynthesis by dietary cholesterol and of cholesterol synthesis by dietary fatty acid. J Lipid Res 1994; 35(2): 311-8
19. Hrtado de Catalfo GE, de Alaniz MJ, et al. Influence of commercial dietary oils on lipid composition and testoerone production in interstitial cells isolated from rat testis. Lipids 2009; 44(4): 345-57.
20. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. Kilic M1, Baltaci AK, Gunay M, Gökbel H, Okudan N, Cicioglu, Neuro Endocrinol Lett 2006 Feb-Apr;27(1-2):247-52.
21. Zinc status and serum testosterone levels of healthy adults. A.S. Prasad, C.S. Mantzoros, F.W. Beck, J.W. Hess, G.J. Brewer. Nutrition 1996 May; 12(5): 344-348.
22. The effects of caffeinated and decaffeinated coffee on sex hormone-binding globulin and endogenous sex hormone levels: a randomized controlled trial. Nicole M WedickEmail author, Christos S Mantzoros, Eric L Ding, Aoife M Brennan, Bernard Rosner, Eric B Rimm, Frank B Hu and Rob M van Dam. Nutrition Journal 2012;11:86 https://doi.org/10.1186/1475-2891-11-86
23. Testosterone Booster Research Update: Fodagia agrestis: Is It the Real Deal? by Robert Schinetsky, September 13th, 2022.
24. Leisegang K, Finelli R, Sikka SC, Panner Selvam MK. Eurycoma longifolia(Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials. Medicina (Kaunas). 2022 Aug 4;58(8):1047. doi: 10.3390/medicina58081047. PMID: 36013514; PMCID: PMC9415500.
25. Chinnappan SM, George A, Pandey P, Narke G, Choudhary YK. Effect of Eurycoma longifolia standardized aqueous root extract-Physta® on testosterone levels and quality of life in ageing male subjects: a randomized, double-blind, placebo-controlled multicentre study. Food Nutr Res. 2021 May 19;65. doi: 10.29219/fnr.v65.5647. PMID: 34262417; PMCID: PMC8254464.
26. Nenezic N, Kostic S, Strac DS, Grunauer M, Nenezic D, Radosavljevic M, Jancic J, Jancic J. Dehydroepiandrosterone (Dhea): Pharmacological Effects And Potential Therapeutic Application. Mini Rev Med Chem. 2022 Sep 19. doi: 10.2174/1389557522666220919125817. Epub ahead of print. PMID: 36121077.
27. Zhang X, Xiao J, Liu T, He Q, Cui J, Tang S, Li X, Liu M. Low Serum Dehydroepiandrosterone and Dehydroepiandrosterone Sulfate Are Associated With Coronary Heart Disease in Men With Type 2 Diabetes Mellitus. Front Endocrinol (Lausanne). 2022 Jun 27;13:890029. doi: 10.3389/fendo.2022.890029. PMID: 35832423; PMCID: PMC9271610.
28. Guo Y, Piasecki J, Swiecicka A, Ireland A, Phillips BE, Atherton PJ, Stashuk D, Rutter MK, McPhee JS, Piasecki M. Circulating testosterone and dehydroepiandrosterone are associated with individual motor unit features in untrained and highly active older men. Geroscience. 2022 Jun;44(3):1215-1228. doi: 10.1007/s11357-021-00482-3. Epub 2021 Dec 3. PMID: 34862585; PMCID: PMC9213614.
29. Liu, TC., Lin, CH., Huang, CY. et al. Effect of acute DHEA administration on free testosterone in middle-aged and young men following high-intensity interval training. Eur J Appl Physiol (2013) 113(7): 1783-92. https://doi.org/10.1007/s00421-013-2607-x
30. Villareal DT, Holloszy JO. Effect of DHEA on Abdominal Fat and Insulin Action in Elderly Women and Men A Randomized Controlled Trial. JAMA. 2004;292(18):2243–2248. doi:10.1001/jama.292.18.2243
31. Tarig Elraiyah, Mohamad Bassam Sonbol, Zhen Wang, Tagwa Khairalseed, Noor Asi, Chaitanya Undavalli, Mohammad Nabhan, Osama Altayar, Larry Prokop, Victor M. Montori, Mohammad Hassan Murad. The Benefits and Harms of Systemic Dehydroepiandrosterone (DHEA) in Postmenopausal Women With Normal Adrenal Function: A Systematic Review and Meta-analysis, The Journal of Clinical Endocrinology & Metabolism, Volume 99, Issue 10, 1 October 2014, Pages 3536–3542, https://doi.org/10.1210/jc.2014-2261
32. Collomp, C. Buisson, F. Lasne, R. Collomp. DHEA, physical exercise and doping, The Journal of Steroid Biochemistry and Molecular Biology, Volume 145, 2015, Pages 206-212,
33. Luboslav Stárka, Michaela Dušková, Martin Hill, Dehydroepiandrosterone: A neuroactive steroid, The Journal of Steroid Biochemistry and Molecular Biology, Volume 145, 2015, Pages 254-260, ISSN 0960-0760, https://doi.org/10.1016/j.jsbmb.2014.03.008.
34. Claes Ohlsson, Liesbeth Vandenput, Åsa Tivesten. DHEA and mortality: What is the nature of the association? The Journal of Steroid Biochemistry and Molecular Biology,Volume 145, 2015, Pages 248-253, ISSN 0960-0760, https://doi.org/10.1016/j.jsbmb.2014.03.006.
35. Giovanni Corona, Giulia Rastrelli, Vito A. Giagulli, Annamaria Sila, Alessandra Sforza, Gianni Forti, Edoardo Mannucci, Mario Maggi. Dehydroepiandrosterone Supplementation in Elderly Men: A Meta-Analysis Study of Placebo-Controlled Trials, The Journal of Clinical Endocrinology & Metabolism, Volume 98, Issue 9, 1 September 2013, Pages 3615-3626, https://doi.org/10.1210/jc.2013-1358
36. Jankowski, C.M., Gozansky, W.S., Van Pelt, R.E., Wolfe, P., Schwartz, R.S. and Kohrt, W.M. (2011). Oral dehydroepiandrosterone replacement in older adults: effects on central adiposity, glucose metabolism and blood lipids. Clinical Endocrinology, 75: 456-463. doi:10.1111/j.1365-2265.2011.04073.x
37. Joanna Karbowska, Zdzislaw Kochan. Fat-reducing effects of dehydroepiandrosterone involve upregulation of ATGL and HSL expression, and stimulation of lipolysis in adipose tissue, Steroids, Volume 77, Issue 13, 2012, Pages 1359-1365, ISSN 0039-128X, https://doi.org/10.1016/j.steroids.2012.08.002.
38. AJ Morales, JJ Nolan, JC Nelson, SS Yen. Effects of replacement dose of dehydroepiandrosterone in men and women of advancing age, The Journal of Clinical Endocrinology & Metabolism, Volume 78, Issue 6, 1 June 1994, Pages 1360-1367.
39. Yokokawa T, Sato K, Iwanaka N, Honda H, Higashida K, Iemitsu M, Hayashi T, Hashimoto T. Dehydroepiandrosterone activates AMP kinase and regulates GLUT4 and PGC-1α expression in C2C12 myotubes. Biochem Biophys Res Commun. 2015 Jul 17-24;463(1-2) 42-47. doi:10.1016/j.bbrc.2015.05.013. PMID: 25983323.
40. Rutkowski, K., Sowa, P., Rutkowska-Talipska. Dehydroepiandrosterone (DHEA): Hypes and Hopes J. et al. Drugs (2014) 74: 1195. https://doi.org/10.1007/s40265-014-0259-8
41. Luboslav Stárka, Michaela Dušková, Martin Hill. Dehydroepiandrosterone: A neuroactive steroid, The Journal of Steroid Biochemistry and Molecular Biology, Volume 145, 2015, Pages 254-260, https://doi.org/10.1016/j.jsbmb.2014.03.008.
42. Alhaj, H.A., Massey, A.E. & McAllister-Williams. R.H. Effects of DHEA administration on episodic memory, cortisol and mood in healthy young men: a double-blind, placebo-controlled study. Psychopharmacology (2006) 188: 541. https://doi.org/10.1007/s00213-005-0136-y
43. Thuzar M, Law WP, Ratnasingam J, Jang C, Dimeski G, Ho KKY. Glucocorticoids suppress brown adipose tissue function in humans: A double‐blind placebo‐controlled study. Diabetes Obes Metab. 2018;20:840–848. https://doi.org/10.1111/dom.13157
44. Hough CM, Lindqvist D, Epel ES, et al. Higher serum DHEA concentrations before and after SSRI treatment are associated with remission of major depression. Psychoneuroendocrinology. 2017;77:122-130. doi:10.1016/j.psyneuen.2016.11.035.
45. Sex hormones and sarcopenia in older persons. Maggio, Marcelloa, B; Lauretani, Fulviob; Ceda, Gian Paolo, Current Opinion in Clinical Nutrition & Metabolic Care: January 2013 - Volume 16 - Issue 1 - p 3-13 doi: 10.1097/MCO.0b013e32835b6044
46. Baker, W.L., Karan, S. and Kenny, A.M. (2011). Effect of Dehydroepiandrosterone on Muscle Strength and Physical Function in Older Adults: A Systematic Review. Journal of the American Geriatrics Society, 59: 997-1002. doi:10.1111/j.1532-5415.2011.03410.x
47. DHEA enhances effects of weight training on muscle mass and strength in elderly women and men Dennis T. Villareal and John O. Holloszy, American Journal of Physiology-Endocrinology and Metabolism 2006 291:5, E1003-E1008
48. Naghii MR, Mofid M, Asgari AR, Hedayati M, Daneshpour MS. Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines. Physiol Pharmacol. 2011; 15 (3) :403-414
49. Nielsen FH, Hunt CD, Mullen LM, Hunt JR. Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. FASEB J 1987; 1:394-7
50. Naghii MR, Samman S. The effect of boron supplementation on the distribution of boron in selected tissues and on testosterone synthesis in rats. J Nutr Biochem 1996;7:507-12
51. Nielsen FH. The emergence of boron as nutritionally important throughout the life cycle. Nutrition 2000;16:512-4.
52. Wilborn C, Taylor L, Poole C, Foster C, Willoughby D, Kreider R. Effects of a purported aromatase and 5α-reductase inhibitor on hormone profiles in college-age men. Int J Sport Nutr Exerc Metab. 2010 Dec;20(6):457-65.
53. Sachin Wankhede, Vishwaraman Mohan, Prasad Thakurdesai. Beneficial effects of fenugreek glycoside supplementation in male subjects during resistance training: A randomized controlled pilot study, Journal of Sport and Health Science, Volume 5, Issue 2, 2016, Pages 176-182.
54. Mohammed R. Haeri, Hamidreza Khalatbari Limaki, Christopher J. Branford White, Kenneth N. White. Non-insulin dependent anti-diabetic activity of (2S, 3R, 4S) 4-hydroxyisoleucine of fenugreek (Trigonella foenum graecum) in streptozotocin-induced type I diabetic rats, Phytomedicine, Volume 19, Issue 7, 2012, Pages 571-574.
55. Tambi, M.I., Imran, M.K. and Henkel, R.R. (2012). Standardized water‐soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late‐onset hypogonadism? Andrologia, 44: 226-230. doi:10.1111/j.1439-0272.2011.01168.x
56. Henkel, R.R., Wang, R., Bassett, S.H., Chen, T., Liu, N., Zhu, Y. and Tambi, M.I. (2014). Tongkat Ali as a Potential Herbal Supplement for Physically Active Male and Female Seniors – A Pilot Study. Phytother. Res., 28: 544-550. doi:10.1002/ptr.5017
57. George A, Henkel R. Phytoandrogenic properties of Eurycoma Longifolia as natural alternative to testosterone replacement therapy. Andrologia. 2014 Sep; 46(7):708-21.
58. Talbott SM, Talbott JA, George A, Pugh M. Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. Journal of the International Society of Sports Nutrition. 2013;10:28. doi:10.1186/1550-2783-10-28.
59. Tambi MI. Eurycoma Longifolia jack: a potent adaptogen in the form of water-soluble extract with the effect of maintaining men’s health. Asian J Androl 2006; 8 (Suppl 1):49-50.
60. World Health Organization (WHO) Laboratory Manual for the Examination of Human Semen and Sperm - Cervical Mucus Interaction. New York: Cambridge University Press; 1999
61. Bin-Seng Low, Sy-Bing Choi, Habibah Abdul Wahab, Prashanta Kumar Das, Kit-Lam Chan. Eurycomanone, the major quassinoid in Eurycoma longifolia root extract increases spermatogenesis by inhibiting the activity of phosphodiesterase and aromatase in steroidogenesis, Journal of Ethnopharmacology, Volume 149, Issue 1, 2013, Pages 201-207, https://doi.org/10.1016/j.jep.2013.06.023.
62. Zanoli P, Zavatti M, Montanari C, Baraldi M. Influence of Eurycoma longifolia on the copulatory activity of sexually sluggish and impotent male rats. J Ethnopharmacol 2009, 126:308–313.
63. Chaing HS, Merino-Chavez G, Yang LL, Wang FN, Hafez ES. Medicinal plants: conception/contraception. Adv Contracept Deliv Syst 1994, 10(3-4):355-63.
64. Tambi MI. Water soluble extract of Eurycoma longifolia in enhancing testosterone in males. In Proceedings of the SupplySide West International Trade Show and Conference. Virgo Publishing; 2003. Oct 1-3.
65. Hamzah S, Yusof A. The ergogenic effects of Tongkat ali (Eurycoma longifolia): A pilot study. British J Sports Med 2003, 37:464-470.
66. Sarina MY, Zaiton Z, Aminudin AHK, Nor AK, Azizol AK. Effects of resistance training and Eurycoma longifolia on muscle strength, lipid profile, blood glucose, and hormone level in middle-aged women. In 4th Asia-Pacific Conference on Exercise and Sport Science & 8th International Sports Science Conference. Academy of Medicine of Malaysia; 2009
67. Ismail SB, Wan Mohammad WM, George A, Nik Hussain NH, Musthapa Kamal ZM, Liske ZM. Randomized clinical trial on the Use of PHYSTA freeze-dried water extract of eurycoma longifolia for the improvement of quality of life and sexual well-being in Men. Evid Based Complement Alternat Med; 2012. doi:10.1155/2012/429268.
68. Talbott S, Talbott J, Negrete J, Jones M, Nichols M, Roza J. Effect of eurycoma longifolia extract on anabolic balance during endurance exercise [abstract]. J Int Soc Sports Nutr 2006, 3(1):S32.
69. Tambi MI. Glycoprotein water-soluble extract of Eurycoma longifolia Jack as a health supplement in management of healthy aging in aged men. The Aging Male 2003, 6(1):41-70
70. Tambi MI. Standardized water-soluble extract of Eurycoma longifolia maintains healthy aging in man. The Aging Male 2007, 10(2):77-87.
71. Shufelt C, Merz CNB, Yang Y, et al. Red Versus White Wine as a Nutritional Aromatase Inhibitor in Premenopausal Women: A Pilot Study. Journal of Women’s Health. 2012;21(3):281-284. doi:10.1089/jwh.2011.3001.
72. Carl Jenkinson, Andrea Petroczi, Declan P Naughton. Red wine and component flavonoids inhibit UGT2B17 in vitro. Nutrition Journal, 2012; 11 (1): 67 DOI: 10.1186/1475-2891-11-67.
73. Jenkinson C, Petroczi A, Naughton DP. Effects of Dietary Components on Testosterone Metabolism via UDP-Glucuronosyltransferase. Frontiers in Endocrinology. 2013;4:80. doi:10.3389/fendo.2013.00080.
74. Wang Y, Lee K, et al. The red wine polyphenol resveratrol displays bilevel inhibition on aromatase in breast cancer cels. Toxicol Sci 2006;92: 71-7
75. Balunas MJ, Su B, Brueggemeier RW, Kinghorn AD. Natural Products as Aromatase Inhibitors. Anti-cancer agents in medicinal chemistry. 2008;8(6):646-682. Suppression of aromatase (estrogen synthetase) by red wine phytochemicals. Eng, Elizabeth T. 1; Williams, Dudley 1; Mandava, Usha 2; Kirma, Nimeer 2; Tekmal, Rajeshwar Rao 2; Chen, Shiuan 1 Breast Cancer Research & Treatment. 67(2):133-146, May 2001.
76. ENG, E.T., WILLIAMS, D., MANDAVA, U., KIRMA, N., TEKMAL, R.R. and CHEN, S. (2002), Anti‐Aromatase Chemicals in Red Wine. Annals of the New York Academy of Sciences, 963: 239-246. doi:10.1111/j.1749-6632.2002.tb04116.x
77. In Vitro Inhibition of Human cGMP-Specific Phosphodiesterase-5 by Polyphenols from Red Grapes Mario Dell'Agli, Germana V. Galli, Urska Vrhovsek, Fulvio Mattivi, and Enrica Bosisio. Journal of Agricultural and Food Chemistry 2005 53 (6), 1960-1965 DOI: 10.1021/jf048497+
78. Yun Wang, Kai Woo Lee, Franky L. Chan, Shiuan Chen, Lai K. Leung. The Red Wine Polyphenol Resveratrol Displays Bilevel Inhibition on Aromatase in Breast Cancer Cells, Toxicological Sciences, Volume 92, Issue 1, 1 July 2006, Pages 71-77, https://doi.org/10.1093/toxsci/kfj190
79. Suppression of Estrogen Biosynthesis by Procyanidin Dimers in Red Wine and Grape Seeds. Elizabeth T. Eng, JingJing Ye, Dudley Williams, Sheryl Phung, Roger E. Moore, Mary K. Young, Ugis Gruntmanis, Glenn Braunstein and Shiuan Chen. Cancer Res December 1 2003 (63) (23) 8516-8522.
80. Modulation of aromatase activity by diet polyphenolic compounds. Rosário Monteiro, Isabel Azevedo, Conceição Calhau. J Agric Food Chem. 2006 May 17; 54(10): 3535-3540.
81. Grape Seed Extract Is an Aromatase Inhibitor and a Suppressor of Aromatase Expression. Ikuko Kijima, Sheryl Phung, Gene Hur, Sum-Ling Kwok and Shiuan Chen. Cancer Res June 1 2006 (66) (11) 5960-5967; DOI: 10.1158/0008-5472.CAN-06-0053.
82. Kao YC, Zhou C, Sherman M, Laughton CA, Chen S. Molecular basis of the inhibition of human aromatase (estrogen synthetase) by flavone and isoflavone phytoestrogens: A site-directed mutagenesis study. Environmental Health Perspectives. 1998;106(2):85-92.
83. Castillo-Pichardo L, Martínez-Montemayor MM, Martínez JE, Wall KM, Cubano LA, Dharmawardhane S. Inhibition of mammary tumor growth and metastases to bone and liver by dietary grape polyphenols. Clinical & experimental metastasis. 2009;26(6):505-516. doi:10.1007/s10585-009-9250-2.
84. Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., Wehr, E., Zittermann, A. Effect of Vitamin D Supplementation on Testosterone Levels in Men. Hormone and Metabolic Research 2011; 43(03): 223-225 DOI: 10.1055/s-0030-1269854
85. Vitamin D and Nandrolone Increase Androgen Receptors. (Paper presented at annual meeting of the Endocrine Society, June 4, 2011.)
86. Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis. Tomlinson, Peter B. et al. Journal of Science and Medicine in Sport, Volume 18, Issue 5 , 575-580
87. Chang E and Kim Y. Vitamin D decreases adipocyte lipid storage and increases NAD-SIRTI pathway in 3T3-LI adipocytes. Nutrition 2016;32, 702-708.
88. Carrillo AE, Flynn MG, Pinkston C, et al. Impact of vitamin D supplementation during a resistance training intervention on body composition, muscle function, and glucose tolerance in overweight and obese adults. Clinical nutrition (Edinburgh, Scotland). 2013;32(3):375-381. doi:10.1016/j.clnu.2012.08.014.
89. Salehpour A, Hosseinpanah F, et al. A 12-week double-blind randomized clinical trial of vitamin D3 supplementation on body fat mass in healthy overweight and obese women. Nutr. J 2014; 11, 78.
90. Pereira‐Santos, M., Costa, P.R., Assis, A.M., Santos, C.A. and Santos, D.B. (2015), Obesity and vitamin D. Obes Rev, 16: 341-349. doi:10.1111/obr.12239
91. Three and six grams supplementation of d-aspartic acid in resistance trained men. Geoffrey W Melville, Jason C Siegler and Paul WM Marshall. Journal of the International Society of Sports Nutrition 2015,12:15 https://doi.org/10.1186/s12970-015-0078-7
92. Darryn S. Willoughby, Brian Leutholtz, d-Aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men, Nutrition Research, Volume 33, Issue 10, 2013, Pages 803-810, https://doi.org/10.1016/j.nutres.2013.07.010
93. Insights into Supplements with Tribulus Terrestris used by Athletes. Andrzej Pokrywka, Zbigniew Obmiński, Jadwiga Malczewska-Lenczowska, Zbigniew Fijałek, Ewa Turek-Lepa, Ryszard Grucza. Journal of Human Kinetics volume 41/2014, 99-105 DOI: 10.2478/hukin-2014-0037 9.
94. Akturk HK, Nippoldt TB. Low Testosterone in Men Should Be a Sign Rather Than a Number to IncreaseA Teachable Moment. JAMA Intern Med. 2016;176(12):1743-1744. doi:10.1001/jamainternmed.2016.5761.
95. Abudayyak, A.T. Jannuzzi, G. Özhan & B. Alpertunga (2014). Investigation on the toxic potential of Tribulus terrestris in vitro, Pharmaceutical Biology, 53:4, 469-476, DOI: 10.3109/13880209.2014.924019
96. Aksu, E.H., Akman, O., Ömür, A.D., Karakuş, E., Can, İ., Kandemir, F.M., Dorman, E. and Uçar, Ö. (2016), 3,3 diindolylmethane leads to apoptosis, decreases sperm quality, affects blood estradiol 17 β and testosterone, oestrogen (α and β) and androgen receptor levels in the reproductive system in male rats. Andrologia, 48: 1155-1165. doi:10.1111/and.12554
97. Plant-derived 3,3′-Diindolylmethane Is a Strong Androgen Antagonist in Human Prostate Cancer Cells J. Biol. Chem. 2003 278: 21136-. doi:10.1074/jbc.M300588200