We scoured the database of the National Center for Biotechnology Information (part of the U.S. National Library of Science) for articles. Of the many ingredients marketed as boosting testosterone levels, we only found four backed by multiple articles based on human testing. For the best chance of boosting testosterone levels, a supplement needs to contain magnesium, fenugreek, and longjack — and some zinc wouldn’t go astray, either.
Does zinc provide testosterone benefits? The answer is, yes. It is an essential mineral which is used in many processes within the body and has a similar role like vitamin D. Men who have a deficiency of zinc may suffer from low testosterone levels but taking zinc supplements can help them to improve the testosterone levels. Zinc deficiency is an essential factor in infertility because it also reduces the sperm count, but with supplements, the sperm count increases along with improvement in testosterone levels. It also helps to recover from high-intensity interval training because that also cause the decline in testosterone levels.
If you do take DAA I recommend cycling it (i.e. 5 days on, 2 off, over 4 weeks then 4 weeks off). And taking it with an aromatase inhibitor (which ensures the aspartic acid doesn’t get converted to estrogen). Especially as more studies are coming out showing the increase in testosterone is limited to a week or two before it drops back to normal levels.
Studies of the effects on cognition of testosterone treatment in non-cognitively impaired eugonadal and hypogonadal ageing males have shown varying results, with some showing beneficial effects on spatial cognition (Janowsky et al 1994; Cherrier et al 2001), verbal memory (Cherrier et al 2001) and working memory (Janowsky et al 2000), and others showing no effects (Sih et al 1997; Kenny et al 2002). Other trials have examined the effects of testosterone treatment in older men with Alzheimer’s disease or cognitive decline. Results have been promising, with two studies showing beneficial effects of testosterone treatment on spatial and verbal memory (Cherrier et al 2005b) and cognitive assessments including visual-spatial memory (Tan and Pu 2003), and a recent randomized controlled trial comparing placebo versus testosterone versus testosterone and an aromatase inhibitor suggesting that testosterone treatment improves spatial memory directly and verbal memory after conversion to estrogen (Cherrier et al 2005a). Not all studies have shown positive results (Kenny et al 2004; Lu et al 2005), and variations could be due to the different measures of cognitive abilities that were used and the cognitive state of men at baseline. The data from clinical trials offers evidence that testosterone may be beneficial for certain elements of cognitive function in the aging male with or without cognitive decline. Larger studies are needed to confirm and clarify these effects.
Dr. Anthony’s Notes: DHEA is a powerful supplement for testosterone, energy, and overall well-being in our older Fit Fathers. A small dose of 25-50mg/day is enough to exert noticeable benefits. This supplement is over-the-counter. Verdict: this is one of the testosterone supplements that work. How To Take DHEA: Take 25-50mg once per day with food. Special Medical Note: DHEA is a MILD CYP3A4 inhibitor (a liver enzyme that processes MANY very common medications). This is the same isoenzyme that Grapefruit inhibits – albeit DHEA inhibits to a much weaker degree. If you’ve ever heard “don’t eat grapefruit with your Lipitor (cholesterol medication)”… this is the reason why. When we inhibit the CYP3A4 enzyme, more of the medications you're taking circulates (it’s not metabolized as fast). Check with your doctor for medication interactions before using DHEA.
According to the Mayo Clinic, testosterone therapy can help treat hypogonadism. This condition occurs when the body can’t produce enough testosterone on its own. However, it’s unclear whether supplements can help. A study published in Nature Reviews Endocrinology found no scientific reason to prescribe testosterone to men over 65 years of age with normal or low to normal testosterone levels.

Erectile dysfunction is a common finding in the aging male. A prevalence of over 70% was found in men older than 70 in a recent cross-sectional study (Ponholzer et al 2005). Treatment with phosphodiesterase-5 (PDE-5) inhibitors is proven to be effective for the majority of men but some do not respond (Shabsigh and Anastasiadis 2003). The condition is multi-factorial, with contributions from emotional, vascular, neurological and pharmacological factors. The concept of erectile dysfunction as a vascular disease is particularly interesting in view of the evidence presented above, linking testosterone to atherosclerosis and describing its action as a vasodilator.
The converse is also true; there is an increased incidence of rheumatic/autoimmune disease in men with hypogonadism. Jimenez-Balderas et al (2001) carried out neuroendocrine, genetic and rheumatologic investigations in hypogonadal men. Of the 13 hypogonadal patients, 8 (61%) had rheumatic autoimmune disease (ankylosing spondylitis, systemic lupus erythemetosus, rheumatoid arthritis, dermatomyositis). There is a low frequency of those diseases (0.83%) in the general population.
The partial synthesis in the 1930s of abundant, potent testosterone esters permitted the characterization of the hormone's effects, so that Kochakian and Murlin (1936) were able to show that testosterone raised nitrogen retention (a mechanism central to anabolism) in the dog, after which Allan Kenyon's group[186] was able to demonstrate both anabolic and androgenic effects of testosterone propionate in eunuchoidal men, boys, and women. The period of the early 1930s to the 1950s has been called "The Golden Age of Steroid Chemistry",[187] and work during this period progressed quickly. Research in this golden age proved that this newly synthesized compound—testosterone—or rather family of compounds (for many derivatives were developed from 1940 to 1960), was a potent multiplier of muscle, strength, and well-being.[188]
If a young man's low testosterone is a problem for a couple trying to get pregnant, gonadotropin injections may be an option in some cases. These are hormones that signal the body to produce more testosterone. This may increase the sperm count. Hedges also describes implantable testosterone pellets, a relatively new form of treatment in which several pellets are placed under the skin of the buttocks, where they release testosterone over the course of about three to four months. Injections and nasal gels may be other options for some men.