Prime Nutrition TestBoost Review

TestBoost is Prime Nutrition’s test-booster which contains just four key ingredients wrapped up in a 1230mg proprietary blend…

Prime Nutrition TestBoost




Stinging Nettle has traditionally been used to treat inflammation resulting in joint and muscle pain, as well as to treat urinary symptoms of prostate enlargement (Benign Prostatic Hyperplasia). It is claimed (mostly by supplement companies) that Stinging Nettle may indirectly boost Testosterone by blocking Sex Hormone Binding Globulin (SHBG). SHBG is a protein that binds to the sex hormones (androgen/estrogen), thus rendering them biologically inactive. The term “free testosterone” refers to Testosterone that is not bound to SHBG, and is therefore free to enter cells and activate Androgen receptors.

A 2012 study, published in “Andrologia”, found that Nettle Extract increased serum Testosterone in rats via 5-alpha-reductase inhibition. However, one human study which sought to determine if Nettle was an effective treatment for BPH also measured Testosterone levels and found no such increase. While the mechanism of action exists by which Stinging Nettle could theoretically increase Testosterone, human studies are lacking and the only one we have to go by produced no such results.

Prime Nutrition does not disclose the exact dose of Stinging Nettle present in TestBoost, but given that the evidence is mostly against Nettle as an effective Test-booster, the dose doesn’t really matter that much.


Tribulus has a well-documented traditional history of use as an aphrodisiac which has contributed to its reputation as an herbal Testosterone booster. However, despite this reputation, Tribulus has never actually been shown to increase Testosterone in healthy human subjects, and even in infertile (low Testosterone) men has produced lackluster results.

A 2005 study, published in the “Journal of Ethnopharamcology” found that 200mg daily (60% saponin content) had no effect on Testosterone in healthy men. These results were replicated in a 2007 study in which 450mg of Tribulus extract daily failed to influence Testosterone levels in male athletes. Even a 2012 study, this time testing the effects of 6g of Tribulus extract on infertile men, found a less than significant trend towards increased Testosterone.

As a libido enhancer, Tribulus may provide the illusion of increased Testosterone but there is absolutely no evidence to suggest it will increase Testosterone. In fact, there is large amount of evidence to the contrary. Prime Nutrition does not disclose the amount of Tribulus present in TestBoost but, as with Stinging Nettle, it doesn’t really matter much anyway because even a high dose would be ineffective for boosting Testosterone.


Taurine is an amino acid with anti-oxidant properties which give it a wide variety of potential health implications. Among these is the ability of Taurine to preserve Testosterone levels in the face of oxidative stress.

A 2010 study from “Amino Acids” found that rats given 1-1.5% Taurine in their drinking water for 5 weeks experienced increased serum and testicular Testosterone levels. These results were replicated in a slightly later (2010) study from the “Journal of Biomedical Science” with 1% Taurine.

Although the effects of Taurine on Testosterone have not been studied specifically in humans, a 2007 study from the “International journal of sport nutrition and exercise metabolism” found no influence on Testosterone in subjects who consumed a multiple-ingredient supplement, 1.5g of which was Taurine.

At this time, it seems unlikely that Taurine will directly increase Testosterone levels in humans. Given the lack of evidence, either anecdotal or clinical, it seems more likely that Taurine can simply serve as a means of preserving Testosterone, though to what degree remains unclear. In the context of TestBoost, we wouldn’t consider it a “key ingredient”.


N-methyl-D-Aspartic Acid (NMDA) is the end-product of supplemental D-Aspartic Acid (DAA), so it is generally alleged to be much more potent on a gram for gram basis. The general claim attached to NMDA is that it is approximately 100 times more potent than standard DAA. Unfortunately, at this time no studies have been conducted comparing these two compounds directly, so the notion that NMDA is 100 times more potent than DAA is a bit of an inference. That being said, NMDA should just carry out the same effects as a higher dose of DAA.

Out of the three human studies done specifically to test the effect of D-Aspartic Acid on Testosterone, two have shown a significant increase in Testosterone levels and one has failed to do so.

A 2012 study from “Advances in Sexual Medicine”, the subjects of which were infertile men (initially low Testosterone) found that 2.66g of D-Aspartic Acid was able to significantly increase Testosterone levels when measured after 90 days of supplementation. These results were in-line with those of an earlier (2009) study in which D-Aspartic Acid supplementation raised Testosterone by 42% after 12 days in healthy men (initially normal Testosterone).

However, a 2013 study published in “Nutrition Research” found that athletes who supplemented with D-Aspartic Acid for 28 days showed no difference in testosterone levels.

The researchers in the failed study noted abnormally high levels of D-aspartate oxidase, the enzyme which degrades D-Aspartic Acid, indicating that prolonged supplementation in individuals with healthy Testosterone levels may cause “negative feedback” which reduces the effects.

Due to a lack of research, it is currently unknown whether NMDA triggers the same sort of negative feedback that DAA does, nor does Prime Nutrition disclose the dose of NMDA present in TestBoost.


The only ingredient in TestBoost with true Testosterone-boosting potential is NMDA but, given the lack of transparency, it’s near impossible to determine whether Prime Nutrition has used an effective dose. The remaining ingredients may serve to slightly optimize Testosterone, but aren’t likely to outright increase it in normal, healthy individuals. Users of TestBoost may also experience some libido enhancement which can easily be confused with increased Testosterone, but will not induce gains in lean mass as increased Testosterone would.

Still not sure which Testosterone Booster is right for you?  Check out our Best Testosterone Boosters List!


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