By Robert Schinetsky

Testosterone is the male sex hormone that makes a man feel like a real man. It peaks in 30s and slowly starts to decline with each passing year. Testosterone impacts libido, vitality, reproduction, and aggression, but that just begins to scratch the surface. It also affects mood, cognition, bone density, muscle mass, body fat percentage, and cardiometabolic health.

With healthy testosterone levels, you feel energized, motivated, and ready to tackle whatever life throws at you. On the other hand, low testosterone levels are known to come with a host of potential downsides (some of the life-threatening), including[1,2,3]:

• Disrupted sleep
• Low libido
• Depression
• Reduced exercise capacity
• Decreased muscle mass
• Increased body fat
• Greater risk of major adverse cardiac events and mortality caused by cardiovascular event

In fact, a recent review published in JAMA low testosterone in men is tied to an increased risk of death.[3] Additional researched published in the Annals of Internal Medicine found that men with low testosterone, high LH, or very low estradiol concentrations had increased all-cause mortality.[4]

Various medications are used to counter the negative cardiometabolic markers that arise with age and an unhealthy lifestyle. One such example is statins.

Statins are one of the most prescribed classes of drugs worldwide to treat hypercholesterolemia and dyslipidemia. By lowering the level of cholesterol, the use of statin could cause a reduction in testosterone levels. Meta-analytic data shows that while statin use can lower testosterone levels, it doesn’t cause it to drop below “normal” levels.[5]

Then, again, “normal” refers to an average…it doesn’t refer to you as an individual.

Testosterone replacement therapy (TRT) is another protocol that aging men may utilize to improve testosterone levels and various other lifestyle conditions. However, many men may not want to resort to hormone therapy, seeking a more natural means to supporting sexual and cardiometabolic health across the lifespan.

Diet, exercise, and quality sleep are essential to maintaining naturally high testosterone levels with age. The Mediterranean diet has been discussed countless times in the AML Articles section for its cardiovascular benefits. Research shows that it also supports healthy testosterone levels compared to a less healthy diet.[6]

As you know, the Mediterranean diet advocates for limited red meat intake and increased seafood intake. Fish are naturally rich in omega-3 polyunsaturated fatty acids and vitamin D, which can promote testosterone synthesis and secretion. Higher intake of total fish, particularly lean fish, is associated with higher serum testosterone levels.[7]

Beyond nutrition, exercise, and sleep, certain dietary supplements are known to support healthy testosterone levels. Common ones include DHEA, zinc, fenugreek, and tongkat ali.

One lesser-known, but formidable, supplement is DCI.

What is DCI?

D-Chiro Inositol (DCI) is a natural molecule that has been studied for its ability to support healthy hormone levels, cardiometabolic health, and brown fat thermogenesis. It is primarily found in tissues that store glucose, such as the liver and skeletal muscles, as well as those involved in androgen production.

Sources of Inositol

Myo-inositol is easily obtainable from whole food sources, including corn, beans, fruits, and nuts. DCI, on the other hand, is scarce in foods, with buckwheat, soy-lecithin, carob, and lentils among the few foods that contain significant amounts of the molecule.

In order for the body to obtain significant quantities of DCI, it must synthesize it from myo-inositol or get it via supplementation.

What Does DCI Do?

DCI exhibits a two-faceted mechanism, playing a role in both insulin signaling and aromatase-facilitated conversion of androgens to estrogen.[8] It is a strong modulator of steroidogenesis and regulates various steroidogenic enzymes, including 17α-hydroxylase, 3β-hydroxysteroid dehydrogenase, and aromatase.[9]

DCI also functions as a second messenger of insulin, which stimulates testosterone synthesis in Leydig cells.[10,11]

Put another way, DCI impacts mechanisms that benefit insulin (a nutrient shuttling hormone that has considerable ramifications in muscle building, fat loss, and cardiometabolic health) as well as testosterone.

DCI Research

Landmark research published in 2021 found that men (average age: 37 years) receiving 500mg d-chiro-inositol twice daily (1 g/day) for 30 days experienced significant reductions in both estrone (-85%) and 17β-estradiol levels (−14.4%) and increases in testosterone (+23.4%), dehydroepiandrosterone (+13.8%) and epiandrosterone (+39%)![12]

Another study from the same year in older men found that supplementation with 600mg of DCI twice per day (1200mg, daily total) for 30 days. At the end of the month-long study, men receiving the 1,200mg d-chiro-inositol supplement demonstrated increased serum testosterone and androstenedione, and reduced oestradiol and oestrone.[13]

Most recently, a narrative review on DCI concluded that it “acts through a variety of mechanisms, acting as an insulin sensitizer, inhibiting the transcription of aromatase, in addition to modulating white adipose tissue/brown adipose tissue transdifferentiation.”[14].

Why is Brown Fat Thermogenesis Important?

Our bodies primarily contains three types of fat cells:

• White fat -- relatively inert form form of stored energy composed of single, large fat droplet
• Brown fat -- cells composed of many small droplets loaded with mitochondria. Brown fat is more metabolically active, burns calories at a higher rate than white fat, and helps maintain core temperature when exposed to cold weather.
• Beige fat -- a newer type of fat cell that lies somewhere between white and brown in terms of its thermogenic properties, meaning it burns more energy than white but less than brown[17]

Brown fat reserves are highest in infants where they help generate heat to maintain a stable body temperature. As we age, though, brown adipose tissue declines.

Therefore, if it’s possible to shift the balance of white fat to brown fat or stimulate the existing brown fat stores, then you may be able to burn more calories (from thermogenesis), thereby reducing overall body fat, bodyweight, and waistline measurements. As it turns out, obesity researchers have been exploring ways to increase brown fat thermogenesis as a safe and effective means to combat the increasing obesity crisis.[15]

Cell studies published in the International Journal of Molecular Science indicate that DCI increases the expression of uncoupling protein 1 (UCP1) -- the main brown adipose tissue marker and can help to transition white fat to brown fat.[16] DCI administration also increased mitochondrial copy number as well as oxygen consumption ratio.[16]

Since DCI has been found to support the “browning” of white fat, it warrants consideration for those interested in improving body composition (as well as those looking to support healthy testosterone levels and insulin sensitivity).

Takeaway

DCI is an untapped reservoir in the modern age of sports nutrition. This advanced supplement supports testosterone, healthy insulin function, body composition, and cardiometabolic well-being.^†

AML DCI Test Booster is a scientifically advanced dietary supplement containing D-Chiro-Inositol (DCI) per capsule. Taken twice daily, AML DCI Test Booster delivers impressive support where you need it most.^†

For added natural testosterone support, we’ve eliminated the guesswork by creating a powerful stack in AML Test and AML DCI Test Booster, which deliver 50mg DHEA and 1,200mg DCI -- the same dosages used in human research studies!^†

For best results, we suggest taking a serving of AML Test and AML DCI Test Booster prior to training as this will work in combination with your intense workouts to support healthy testosterone levels.^†

^{† These statements have not been evaluated by the Food and Drug administration. This product is not intended to diagnose, treat, cure, or prevent any disease.}

^{© Published by Advanced Research Media, Inc. 2024}

^{© Reprinted with permission from Advanced Research Media, Inc.}

References

1. Oskui, P. M., French, W. J., Herring, M. J., Mayeda, G. S., Burstein, S., & Kloner, R. A. (2024). Testosterone and the Cardiovascular System: A Comprehensive Review of the Clinical Literature. Journal of the American Heart Association, 2(6), e000272. https://doi.org/10.1161/JAHA.113.000272
2. Zhan X, Liu Y, Chen T, Wan H, Xiong S, Li S, Deng X, Chen L, Fu B. The association between serum testosterone level and congestive heart failure in US male adults: data from National Health and Nutrition Examination Survey (NHANES) 2011-2016. Reprod Biol Endocrinol. 2024 Jan 2;22(1):4. doi: 10.1186/s12958-023-01171-w. PMID: 38169409; PMCID: PMC10759552.
3. Harris E. Meta-Analysis: Low Testosterone in Men Tied to Increased Risk of Death. JAMA. 2024;332(1):8. doi:10.1001/jama.2024.10334
4. Bu B. Yeap, Ross J. Marriott, Girish Dwivedi, et al. Associations of Testosterone and Related Hormones With All-Cause and Cardiovascular Mortality and Incident Cardiovascular Disease in Men: Individual Participant Data Meta-analyses. Ann Intern Med.2024;177:768-781. [Epub 14 May 2024]. doi:7326/M23-2781
5. Glina FPA, Lopes L, E Silva RS, Barros EAC, Biselli B, Glina S. Do statins decrease testosterone in men? Systematic review and meta-analysis. Int Braz J Urol. 2024 Mar-Apr;50(2):119-135. doi: 10.1590/S1677-5538.IBJU.2023.0578. PMID: 38386784; PMCID: PMC10953607.
6. Corsetti V, Notari T, Montano L. Effects of the low-carb organic Mediterranean diet on testosterone levels and sperm DNA fragmentation. Curr Res Food Sci. 2023 Nov 15;7:100636. doi: 10.1016/j.crfs.2023.100636. PMID: 38045510; PMCID: PMC10689274.
7. Ito A, Yamamoto S, Inoue Y, Fukunaga A, Nanri A, Konishi M, Yamamoto S, Nakagawa T, Mizoue T. Association between Fish Intake and Serum Testosterone Levels in Older Males: The Hitachi Health Study II. Curr Dev Nutr. 2024 Mar 5;8(4):102133. doi: 10.1016/j.cdnut.2024.102133. PMID: 38584675; PMCID: PMC10997911.
8. Bezerra Espinola MS, Laganà AS, Bilotta G, Gullo G, Aragona C, Unfer V. d-chiro-inositol induces ovulation in non-Polycystic Ovary Syndrome (PCOS), non-insulin-resistant young women, likely by modulating aromatase expression: a report of 2 cases. Am J Case Rep. 2021;22:e932722.; Montt-Guevara MM, Finiguerra M, Marzi I, Fidecicchi T, Ferrari A, Genazzani AD, et al. d-Chiro-Inositol regulates insulin signaling in human adipocytes. Front Endocrinol. 2021;12:660815.
9. Gambioli R, Montanino Oliva M, Nordio M, Chiefari A, Puliani G, Unfer V. New Insights into the Activities of D-Chiro-Inositol: A Narrative Review. Biomedicines. 2021 Oct 2;9(10):1378. doi: 10.3390/biomedicines9101378. PMID: 34680494; PMCID: PMC8533370.
10. Leisegang K, Henkel R. The in vitro modulation of steroidogenesis by inflammatory cytokines and insulin in TM3 Leydig cells. Reprod Biol Endocrinol. 2018;16:26. doi: 10.1186/s12958-018-0341-2.
11. Pitteloud N, Hardin M, Dwyer AA, Valassi E, Yialamas M, Elahi D, et al. Increasing insulin resistance is associated with a decrease in Leydig cell testosterone secretion in men. J Clin Endocrinol Metab. 2005;90:2636–41. doi: 10.1210/jc.2004-2190.
12. Monastra G., Vazquez-Levin M., Bezerra Espinola M.S., Bilotta G., Laganà S., Unfer V. D-chiro-inositol, an aromatase down-modulator, increases androgens and reduces estrogens in male volunteers: A pilot study. Basic Clin. Androl. 2021;31:1–17. doi: 10.1186/s12610-021-00131-x.
13. Nordio M, Kumanov P, Chiefari A, Puliani G. D-Chiro-Inositol improves testosterone levels in older hypogonadal men with low-normal testosterone: a pilot study. Basic Clin Androl. 2021 Nov 12;31(1):28. doi: 10.1186/s12610-021-00146-4. PMID: 34763665; PMCID: PMC8588714.
14. Simona Dinicola, Vittorio Unfer, Christophe O. Soulage, Maria Isidora Margarita Yap-Garcia, Arturo Bevilacqua, Salvatore Benvenga, Daniele Barbaro, Artur Wdowiak, Maurizio Nordio, Didier Dewailly, Marialuisa Appetecchia, Cesare Aragona, Maria Salomè Bezerra Espinola, Mariano Bizzarri, Pietro Cavalli, Annamaria Colao, Rosario D'Anna, Mónica Hebe Vazquez-Levin, Imelda Hernàndez Marin, Zdravko Kamenov, Antonio Simone Laganà, Giovanni Monastra, Mario Montanino Oliva, Ali Cenk Özay, Basilio Pintaudi, Giuseppina Porcaro, Olga Pustotina, Lali Pkhaladze, Nikos Prapas, Scott Roseff, Saghar Salehpour, Annarita Stringaro, Marat Tugushev, Virginia Unfer, Ivana Vucenik, Fabio Facchinetti; d-Chiro-Inositol in Clinical Practice: A Perspective from the Experts Group on Inositol in Basic and Clinical Research (EGOI). Gynecol Obstet Invest 2024; https://doi.org/10.1159/000536081
15. Seale P, Lazar MA. Brown fat in humans: turning up the heat on obesity. Diabetes. 2009;58(7):1482-4.
16. Monastra G, Gambioli R, Unfer V, Forte G, Maymo-Masip E, Comitato R. D-Chiro-Inositol and Myo-Inositol Induce WAT/BAT Trans-Differentiation in Two Different Human Adipocyte Models (SGBS and LiSa-2). Int J Mol Sci. 2023 Apr 18;24(8):7421. doi: 10.3390/ijms24087421. PMID: 37108582; PMCID: PMC10139407.
17. Tongtong Wang et al, Single-nucleus transcriptomics identifies separate classes of UCP1 and futile cycle adipocytes, Cell Metabolism (2024). DOI: 10.1016/j.cmet.2024.07.005