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science nutrition blog

science nutrition <strong>blog</strong>

By: Robert A. Schinetsky


For decades, supplement companies have been making profits hand over fist selling consumers grossly overpriced, underdosed products.

(And, no, it’s not the pixie-dusted, “ultra” concentrated pre workouts that were nothing more than delicious-tasting caffeine powders.)

The bogus products that have been draining your wallet and fattening the bank accounts of supplement companies are the so-called “natural testosterone boosters.” Billed as the saving grace to your low testosterone levels, poor body composition, and pitiful strength levels, natty test boosters were viewed by consumers as the answer to everything that was wrong.

The sad truth, is that these purported testosterone support products were completely and utterly useless. They did absolutely nothing for testosterone production due to the simple fact that they didn’t contain any ingredients shown in human research trials to actually support testosterone production. Sure, they included all sorts of ancient herbs and botanical extracts that worked well in rats, but nary a compound that would actually benefit a real live human being.

So if you have questions about Turkesterone vs Tongkat Ali, Fenugreek vs Tongkat Ali and how these natural testosterone boosters compare, we’ve assembled a list of what works and what doesn’t. Keep reading to learn the top 5 supplements you want to avoid wasting money on when purchasing a testosterone support product as well as the 5 best natural testosterone boosters on the market.

Let’s get right to it!

5 Worst Natural Testosterone Boosters

D-Aspartic Acid (DAA)

D-Aspartic Acid is one of two isomers of the non-essential amino acid aspartate (aspartic acid).

It’s one of the oldest natural testosterone boosters on the market touted to help improve performance and stamina. And, it can still be found in countless products these days.

Upon initial inspection, it’s easy to see why tongkat ali so many people fall for the hype surrounding DAA. Several early studies noted that supplementing with the non-essential amino acid increased testosterone levels in both humans and rats.[1]

However, the “catch” with DAA is that the increase in testosterone levels is rather temporary. In otherwise healthy males, the test-boosting benefits of DAA disappeared roughly 4 weeks after continuous use.

More recent studies, however, paint a very different picture of the effects of d-aspartic acid supplementation.

A study from 2013 noted that D-aspartic acid did not boost testosterone levels nor did it improve any aspect of performance.[2]

Another study in 2015 by Melville and friends gave subjects either three or six grams of DAA per day for a 14 days (2 weeks). Researchers noted that the 3g dose of D-aspartic acid did not result in any meaningful changes in testosterone levels (or any other anabolic hormones for that matter).[3] However, the group of men receiving 6g per day experienced a significant reduction in both total testosterone and free testosterone levels, with no concurrent change in other hormones tested.[3]

Then in 2017, Melville carried out another study on DAA.[4] This time he recruited 22 men in a randomized, double-blind fashion and had them consume either a placebo or 6g of DAA. After 12 weeks of supplementation, researchers observed that DAA had no significant impact on resting levels of either free or total testosterone. Any improvements in strength or hypertrophy were similar to those in the placebo group.

At best, DAA will lead to a small, transient boost in testosterone levels with effects subsiding after 4 weeks of continuous use. At worst, supplementation with D-Aspartic Acid will lead to a significant drop in both free and total testosterone levels -- precisely what you don’t want from a product claiming to enhance your testosterone levels.

Tribulus Terrestris

Tribulus terrestris is a staple herb of Ayurveda and Traditional Chinese Medicine historically used to a variety of potential reasons, including to enhance libido, support urinary tract health, and reduce swelling.[5]

Today, tribulus is sold as an all-natural means to improve sexual health and athletic performance. The popularity of tribulus as a natty test booster began when Eastern Bloc athletes used it to boost testosterone production and improve performance.  

At the time, Soviet scientists hypothesized that the herb mimics the actions of luteinizing hormone (LH) to stimulate testosterone release in the testes. In fact, animal studies have found that Tribulus terrestris may increase testosterone.[6]

However, the pro-testosterone benefits of tribulus have not been successfully replicated in humans. Numerous well-controlled studies have found that tribulus has no effect on strength, body composition, or testosterone![7,8,9]

In fact, a recent meta-analysis from 2016 concluded the following regarding tribulus terrestris as a natural testosterone booster:

“It is becoming increasingly clear that the deep-seated traditional view of TT bioactivity focused exclusively on its androgen enhancing properties is outdated and incapable for accommodating the emerging evidence from recent clinical and experimental studies pointing toward new and, perhaps, more plausible modes of action.”[10]

In other words, save your money and pass on tribulus.

Maca Root

Maca (Lepidium meyenii) is a plant found almost exclusively in the mountainous regions of Peru. It’s closely related to cruciferous vegetables such as broccoli, cauliflower, and Brussels sprouts and can also be found under the name Peruvian ginseng.[11]

Historically, maca was used as a form of currency for trade, but more well-known is the role the powerful plant played an as an all-natural medicine for over 3,000 to boost nutrition and to enhance fertility.

The primary benefits of maca are regarding libido enhancement as well as an adaptogen. In case you weren’t aware, adaptogens are botanicals that, when consumed, improve the body’s ability to interact, respond, and recover from all manner of physical, emotional, and psychological stress.

Regarding research-backed benefits in humans, maca appears to be effective for increasing libido and sexual desire (in men AND women) as well as restoring erectile function.[12,13]

However, based on the current body of evidence, supplementation with maca DOES NOT increase testosterone levels or any other other hormones which impact testosterone production, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH).[12,14,15]

Regarding its potential benefits as an adaptogen, research notes its more effective for women as the adaptogenic-focused maca studies using men show no improvement.

The takeaway here is that maca may be useful for helping you feel more aroused or “in the mood,” but as far as actually increasing T-levels, it’s a dud.

Indole-3-Carbinol (I3C) & 3,3-Diindolylmethane (DIM)

Indole-3-carbinol (I3C) is a compound naturally occurring in cruciferous vegetables (broccoli, kale, collard greens, etc.) resulting from the breakdown of the glucosinolate glucobrassicin.

I3C is then further broken down in the body to a compound called diindolylmethane, or DIM for short. In a sense, DIM is a more “refined” form of I3C.

What do a couple of broccoli-derived compounds have to do with natural testosterone production?

Well, these two compounds are routinely sold as anti-estrogen supplements due to some research indicating I3C (and DIM) can affect estrogen metabolism and activity, and in small amounts may inhibit the aromatase enzyme.[15,16,17] Inhibiting aromatase would subsequently prevent conversion of testosterone into estrogen.

Additionally, I3C and DIM may act on more potent forms of estrogen and convert them into less powerful forms, which theoretically would reduce the overall effects of estrogen in the body.

And, there’s some research to back this up too. Various studies have noted that I3C and DIM can alter estrogen metabolism and thereby beneficially impact various forms of estrogen-sensitive cancers.[18]

However, DIM can come with some fairly unwanted side effects. Specifically, taking too much DIM at once can actually increase aromatase enzyme functioning and result in greater estrogen synthesis and activity.[20]

Due to these potential anti-androgenic effects, DIM (as well as I3C) cannot be recommended as one of the best natural testosterone boosters.

If you want to get the health benefits from these compounds, you’d better served to get them from actually eating cruciferous veggies and not supplementing with these compounds en masse. 

Saw Palmetto

Saw palmetto (Serenoa repens) is a small palm found throughout the Southeastern United States routinely sold as a supplement for prostate health and testosterone enhancement.

More specifically, saw palmetto is frequently used to suppress prostate growth and combat abnormal urine flow that results from an enlarged prostate. The reason it is believed that saw palmetto can combat prostate hyperplasia is based on some research indicating it may block an enzyme (5-alpha-reductase) that converts testosterone into dihydrotestosterone (DHT).[21]

However, most well-designed studies show that saw palmetto does not improve measures of urinary flow or prostate size.[22,23]

Regarding potential testosterone enhancement, the studies noting increases in T-levels from saw palmetto supplementation are confounded by other compounds being included with saw palmetto, and the one study using saw palmetto in isolation noted no beneficial impact on testosterone levels.[24,25]

5 Best Natural Testosterone Boosters

Dehydroepiandrosterone (DHEA)

DHEA is a naturally occurring prohormone synthesize in the brain, gonads and adrenal glands that serves as a precursor to testosterone. It’s commonly referred to as a potential “fountain of youth” for its ability to improve vitality, health, and free testosterone levels.

Unfortunately, DHEA levels, similar to testosterone, peak around age 30 and gradually decline with age, reducing recovery and muscle growth while accelerating aging. On top of that, low levels of DHEA are also associated with increased abdominal fat storage and greater risk of CVD.

To circumvent this decline, many adults (men AND women) supplement with DHEA.

Research notes that supplementation with DHEA may[26,27,28,29]:

- Improve insulin sensitivity

- Decrease cortisol levels (indirectly enhancing testosterone)

- Reduce abdominal fat

- Boost metabolism

- Fortify immune function

- Strengthen bones

- Enhance the anabolic effects of weight training

- Increase IGF-1

- Prevent muscle loss

In addition to these effects, DHEA supplementation also increases FREE testosterone levels. As you may or may not know, testosterone is found in the body in both free and bound forms. Free testosterone is the biologically active kind that we want more of in order to improve energy, strength, recovery, and sexual function. Bound testosterone is biologically inactive, due to serum hormone-binding globulin (SHBG).

Additionally, supplementation with DHEA has been noted to increase free T-levels following high-intensity interval training (HIIT), which has been noted to suppress testosterone.

Perhaps most importantly, DHEA supplementation does not adversely impact levels of sex hormone-binding globulin or estrogen (estrone or estradiol) in men or women.[30] All the benefits with none of the drawbacks of other testosterone-boosting means makes DHEA an easy candidate for the best natural testosterone booster around. 

Tongkat Ali (Longjack)

Tongkat ali (a.k.a. Longjack, a.k.a. Eurycoma Longifolia) is a foundational compound of Ayurveda, commonly used as an aphrodisiac. Similar to DHEA, longjack has been found to be effective in both men and women for improving libido, total and free testosterone concentrations as well as muscle mass and strength in men and women! And, unlike many of the other old world herbs commonly touted as natural testosterone boosters, longjack actually has a fair amount of human research denoting its benefits which explains why many popular companies of set out to try and create the best tongkat ali supplement.

For example, a 2011 study noted that supplementation with 100mg longjack extract increased muscle size and strength. When subjects consumed 200mg and 400mg of the extract, they experienced increases in both free and total testosterone levels.[31,32,33]

It should be noted that the research involving longjack isn’t relegated solely to older men either (most studies investigating natural testosterone boosters are conducted using men 40-50+).

Studies using young, healthy men (average 25 years of age) document significant improvements in strength, lean body mass, arm size, and serum testosterone levels. There is a lot of information out there regarding turkesterone vs. Tongkat Ali, and the benefits that each supplement may or may not have or how the two can potentially be stacked together for added benefits.

And, to top it off, some animal studies note that tongkat ali may also improve erectile function and delay ejaculation. This suggests that longjack might help men with erectile dysfunction and premature ejaculation -- two of the most common sexually-related problems for men.[35]


Boron is an essential trace mineral found in the human body that’s impacts a wide variety of mechanisms in the body, including[36]:

- Bone growth and maintenance of bone

- wound healing;

- Utilization of vitamin D, testosterone, and estrogen

- magnesium absorption

- Reducing levels of inflammatory biomarkers, such as C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α)

You might be interested to know it has also been used an an ingredient in testosterone support supplements since the 1980s.

Why is that?

Because, boron helps boost testosterone levels.

In fact, studies demonstrate that supplementation with 10 mg of boron per day for a week increased free testosterone by 28% and decreased estrogen levels by 39%![36] It also can decrease levels of sex-hormone binding globulin (SHBG), making testosterone more biologically active.

Other benefits attributed to boron supplementation include reduced levels of inflammatory biomarkers and improved cognitive function.[37,38]

Vitamin D

Also known as the “sunshine” vitamin, Vitamin D is a fat-soluble vitamin that serves an an important prohormone in the body, impacting synthesis of numerous steroid hormones, including testosterone.

Despite the importance of vitamin D, many individuals are chronically deficient in it due to a lack of time spent outdoors. The result of the deficiency is low blood testosterone as well as an increased risk of CVD and cancer.

Fortunately supplementation of Vitamin D3 has been noted to significantly boost testosterone levels up to 20%.[40,41] This occurs via a reduction in sex-hormone binding globulin (SHBG) and aromatase expression, which limits the breakdown of testosterone into estrogen. It’s also worth mentioning that Vitamin D3 has been shown to raise levels of the anabolic hormone IGF-1.[42,43]

And if you needed any more reason to supplement with Vitamin D, consider this -- it can cut body fat while increasing power output. A study conducted at Purdue University reported that when subjects consumed 4,000 IU of vitamin D per day they improved peak power output and waist-to-hip ratio.


Often people compare the benefits of Fenugreek vs tongkat for their benefits, and although they have some similarities, they have distinctive properties. Fenugreek (Trigonella Foenum-Graecum) is another staple of Ayurveda that was historically used for its anti-diabetic and cholesterol-lowering properties. The plant is rich in glycosides and steroidal saponins that have been noted in human research trials to inhibit aromatase and boost free testosterone levels.[44,45]

In fact, a 2010 study using college-aged men found that consuming 500mg of a standardized fenugreek extract for 4 weeks led to significant increases in biologically active (free) testosterone as well as a reduction in body fat.[44]

At the conclusion of the trial, researchers stated:

“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.”

In other words, fenugreek supplementation resulted in higher free testosterone levels and reduced aromatase activity.

More recently, a study from 2015 noted that consuming 600mg daily of standardized fenugreek extract for eight weeks increased free testosterone levels compared to placebo. The test group also experience an increase the the number of repetitions the could perform in the leg press before reaching failure. And, to top it off, subjects receiving the fenugreek supplement dropped body fat without losing strength.

Most importantly, supplementation with fenugreek comes without any clinical side effects, the same of which cannot be said for many testosterone boosting products.

What About Injectable Anabolic Steroids?

Now, many men bypass the natty test booster category altogether, head straight for designer anabolic steroids, and start injecting testosterone (among other things). And, while exogenous testosterone administration will always trump the effects of natural testosterone boosters, that instant gratification does not come without a long, dreadful list of unwanted consequences.

First and foremost, when you start taking exogenous testosterone, your body downregulates endogenous testosterone production. If and when you decide to stop injecting testosterone, there’s a fairly good chance that your body won’t rebound to its normal production status, leaving you to face shutdown.

By “shutdown” we mean that your body’s normal production of the hormone stops, often resulting in the testicles softening and shrinking. As a result of stopping testosterone injections or even TRT, you can experience low energy, low sex drive, increased irritability, and even depression.

Now, it might be tempting to consider TRT, especially given the number of TV and radio commercials sponsored by clinics willing to given exogenous testosterone to any man claiming the symptoms of low testosterone.

However, the FDA classifies low T-levels as those below 300 nanograms per deciliter and only approves TRT for men with proven levels.

The FDA also advises that men who have had a stroke or heart attack within the last six months or who are at high risk for prostate cancer avoid testosterone replacement therapy due to various studies indicating it can lead to cardiovascular complications and toxicity.

The bottom line here, is that you should only consider TRT as a last resort and not as a quick means to building muscle and strength quicker. There’s far too many downsides and potential complications to warrant experimenting with designer steroids and injectable anabolics.

However, if you are looking for an all-natural, scientifically-backed way to naturally enhance testosterone production, you need to check out AML Test!

AML Test -- The Best Natural Testosterone Booster

AML TEST is designed to boost free testosterone, not total testosterone. It is first and only testosterone support formula to uses ingredients proven to actually improve testosterone levels in humans.

AML Test includes each of the best natural testosterone boosters discussed above as well as red wine polyphenols which function as powerful, all-natural aromatase inhibitors that lower estrogen and increase testosterone levels. These polyphenols also boost nitric oxide production which enhances vasodilation and blood flow to all regions of the body.

In addition to AML Test, other ways to maximize natural testosterone production include consistent bouts of resistance training, stress management, adequate dietary fat intake, and quality sleep.

In doing so, you’ll create the ideal hormonal environment to optimize testosterone production, leading to greater mood, muscle mass, strength, and longevity.

Click here to learn more about AML Test and why it’s the king of natural testosterone boosters!



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