Test HD is a test-booster by MuscleTech which consists of several alleged test-boosting ingredients with varying degrees of efficacy…FIND IT HERE
Zinc is required for the conversion of cholesterol (and other lipids) into sex hormones, as well as the existence of androgen receptors, as evidenced in a 1996 study, in which rats fed a zinc deficient diet experienced a decrease in androgen receptor sites and an increase in estrogen receptor sites. So while Zinc deficiency can certainly result in low testosterone, there is no evidence indicating that supplemental Zinc can increase Testosterone above normal. In fact, there is only evidence to the contrary.
A 2009 study, published in the “European Journal of Clinical Nutrition”, concluded that zinc (ZMA) supplementation had no influence on serum testosterone levels in non-zinc deficient men. A similar failure to influence testosterone via zinc supplementation was seen in a 2011 study, the subjects of which were trained cyclists who consumed sufficient dietary zinc.
However, a 2005 study, the subjects of which were wrestlers, demonstrated that zinc supplementation was able to attenuate exercise-induced declines in testosterone levels. The evidence is quite clear: Zinc supplementation will not increase testosterone above baseline in healthy, non-zinc deficient humans, but can be effective for maintaining consistent testosterone levels.
In several studies, Tribulus has demonstrated aphrodisiac properties that were originally thought to be the result of increased testosterone. This is mainly due to Tribulus being shown to increase levels of testosterone in certain animal studies.
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. Ultimately, the popularity of Tribulus as a testosterone booster seems unwarranted given than it has unreliably increased testosterone in rodents and has never been shown to significantly increase testosterone in humans, healthy or not.
Tribulus may increase libido and sexual well-being, creating the illusion of increased testosterone, but the science is very clear: Tribulus does not increase testosterone in healthy humans.
SHILAJIT (FULVIC ACID)
A 2010 study published in “Andrologia” found that supplementation with 200mg Shilajit (containing 55% Fulvic Acid) daily for 90 days resulted in a rise in testosterone levels in infertile men. One dose of Test HD contains100mg Shilajit (50mg Fulvic acid), so two doses would be required to roughly achieve the same dose. Furthermore, and most importantly, Shilajit has not demonstrated the same effect on testosterone levels in healthy men. There is no evidence to conclude the average individual with normal test levels will benefit from Shilajit supplementation.
Boron has somewhat of a questionable track record regarding it’s use as a test booster. In the early days of bodybuilding, Boron became popular, but then lost popularity (one would think because it doesn’t work).
Recently, however, Boron is making a come-back with the same claims attached to it. A 2011 study, published in the “Journal of Trace Minerals in Medicine and Biology”, found that boron supplementation (11.6 mg daily) over a one week period was found to increase testosterone to a statistically significant degree (28%).
An earlier study (1993), found that daily supplementation with 2.5 mg of boron over a 7 week period failed to increase testosterone levels. The obvious reason for the discrepancy is that the 2011 study used 4-5 times as much boron as the earlier study. While there does appear to be something here, we would still consider the evidence a bit too inconclusive to be sold on boron as a test booster. However, preliminary evidence suggests high doses (over 10mg) may be effective.
Diindolylmethane (DIM) is a byproduct created during the digestion of Indole-3-Carbinol (found in vegetables such as Broccoli). Similarly to Cimicifuga Racemosa, Diindolylmethane (DIM) has been shown to inhibit estrogen in women with breast cancer, but DIM is tricky when it comes to its effects on estrogen. In low doses, DIM has been shown to act as an aromatase inhibitor (anti-estrogen). Aromatase is the enzyme responsible for the conversion of testosterone to estrogen. By blocking the action of this enzyme, less testosterone is converted into estrogen, and the result is increased levels of testosterone relative to estrogen.
A 2011 study found that, when given to subjects at a dose of 300mg daily for 14 days, DIM produced anti-estrogenic effects. Under different circumstances however, DIM has shown the opposite, meaning it actually has the capacity to increase estrogen. So, rather than labeling DIM as pro-estrogen or anti-estrogen, it should be considered an estrogen modulator (meaning it has the ability to alter levels of estrogen one way or another). In order to understand how this actually works, we need to back up and clear a few things up. First, the term “estrogen” is actually an umbrella term for a family of compounds.
The members of this family are all different, and therefore have different functions and effects in the body. The types body builders and cancer patients alike hate, reffered to as “bad estrogens”, are 16a-hydroxyestrogens and 4-hydroxyestrogens. When we use the term “good estrogen” we are referring to 2-hydroxyestrogens. DIM appears to increase the level of 2-hydroxyestrogens, relative to the other types which results in less of an “estrogen-like” effect, while still technically increasing overall estrogen.
STINGING NETTLE ROOT EXTRACT
Stinging Nettle, like most herbal compounds that find their way into supplements, has a long history of use, dating back many centuries. Currently, stinging nettle is 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 lowering 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. No studies have actually confirmed increased testosterone levels as a result of supplementation with SN.
A 2012 study, published in “Andrologia”, found that Stinging Nettle Extract increased serum testosterone in rats via 5-alpha-reductase inhibition. However, one human study which sought to determine if Stinging 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.
You may have also seen this listed as Velvet Bean extract on other supplements (PowerFULL by USP comes to mind). To make a long story short, Mucuna Pruriens contain a compound called L-Dopa which primarily acts as a precursor to the neurotransmitter Dopamine. You may also come across the actual compound L-Dopa as an ingredient in certain supplements which most likely means it was created synthetically.
Aside from increasing dopamine, a 2008 study found that “Treatment with M. pruriens regulates steroidogenesis and improves semen quality in infertile men.” In addition to increased levels of dopamine, adernaline, and noradrenaline, the subjects who recieved Mucuna Pruriens also experienced elevated testosterone levels. We generally caution against consuming substances that drastically alter neurotransmitters, but given the relatively low level of Mucuna Pruriens present in the Test Poweder formula, the risks seem relatively low.
However, there is no evidence that Mucuna Pruriens effectively raise testosterone in individuals with normal testosterone levels already. Those suffering from low testosterone levels are much more likely to benefit from supplementation.
THE BOTTOM LINE
Test HD contains the usual blend of alleged testosterone boosting ingredients (Tribulus, Stinging Nettle, etc.) Despite the popularity of these ingredients, it is likely that they will only increase testosterone levels in deficient individuals. Ultimately, Test HD may certainly be useful for maintaining consistently optimized testosterone levels, but it is unlikely to boost testosterone beyond baseline.
Still not sure which Testosterone Booster is right for you? Check out our Best Testosterone Boosters Review!
- Biswas, Tuhin Kanti, et al. “Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia.” Andrologia 42.1 (2010): 48-56.
- Ferrando, A. A., and N. R. Green. “The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders.”International journal of sport nutrition 3.2 (1993): 140.
- Nielsen, Forrest H., et al. “Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women.” The FASEB journal 1.5 (1987): 394-397.
- Koehler, K., et al. “Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement.” European journal of clinical nutrition 63.1 (2009): 65-70.
- Neek, Leila Shafiei, Abas Ali Gaeini, and Siroos Choobineh. “Effect of zinc and selenium supplementation on serum testosterone and plasma lactate in cyclist after an exhaustive exercise bout.” Biological trace element research 144.1-3 (2011): 454-462.
- Kilic, Mehmet, et al. “The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc.” Neuro endocrinology letters 27.1-2 (2005): 247-252.
- Om AS, Chung KW. Dietary zinc deficiency alters 5 alpha-reduction and aromatization of testosterone and androgen and estrogen receptors in rat liver. J Nutr. (1996)
- Rogerson, Shane, et al. “The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players.” The Journal of Strength & Conditioning Research 21.2 (2007): 348-353.
- Sellandi, Thirunavukkarasu M., Anup B. Thakar, and Madhav Singh Baghel. “Clinical study of Tribulus terrestris Linn. in Oligozoospermia: A double blind study.” Ayu 33.3 (2012): 356.
- Nahata, A., and V. K. Dixit. “Ameliorative effects of stinging nettle (Urtica dioica) on testosterone‐induced prostatic hyperplasia in rats.” Andrologia 44.s1 (2012): 396-409.
- Wilborn C, et al. Effects of a purported aromatase and 5α-reductase inhibitor on hormone profiles in college-age men. Int J Sport Nutr Exerc Metab. (2010)
- Hong, Chibo, Gary L. Firestone, and Leonard F. Bjeldanes. “Bcl-2 family-mediated apoptotic effects of 3, 3′-diindolylmethane (DIM) in human breast cancer cells.” Biochemical pharmacology 63.6 (2002): 1085-1097.
- Rajoria, Shilpi, et al. “3, 3′-Diindolylmethane Modulates Estrogen Metabolism in Patients with Thyroid Proliferative Disease: A Pilot Study.” Thyroid 21.3 (2011): 299-304.
- Sanderson, J. Thomas, et al. “2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin and diindolylmethanes differentially induce cytochrome P450 1A1, 1B1, and 19 in H295R human adrenocortical carcinoma cells.” Toxicological sciences 61.1 (2001): 40-48.