A handful of supplements have shown measurable effects on testosterone in clinical trials, but the results are modest and depend heavily on your starting point. Men who are deficient in key minerals or hormonal precursors tend to see the biggest gains. If your levels are already in the normal range, most supplements will do little to move the needle.
Ashwagandha
Ashwagandha is one of the most consistently supported natural supplements for testosterone. In a 16-week randomized, placebo-controlled crossover study published in the American Journal of Men’s Health, overweight men aged 40 to 70 took 600 mg of ashwagandha extract daily for 8 weeks. Compared to placebo, testosterone increased by 14.7% and DHEA-S (a precursor hormone) increased by 18%. These were statistically significant results in a well-designed trial.
The extract used in that study delivered 21 mg of withanolide glycosides per day, which is the active compound class you want to look for on a label. Ashwagandha is classified as an adaptogen, meaning it helps the body manage stress. One proposed mechanism is that by lowering cortisol (your primary stress hormone), it creates a more favorable hormonal environment for testosterone production, though the study above didn’t find a significant change in cortisol itself.
Boron
Boron is a trace mineral that flies under the radar but has some striking short-term data. In a small study of healthy men, just 6 mg per day of boron for one week raised free testosterone from an average of 11.83 pg/mL to 15.18 pg/mL, roughly a 28% increase. Free testosterone is the fraction that your body can actually use. About 98% of your total testosterone is bound to proteins in the blood and unavailable to tissues, so even a small shift toward unbound testosterone can be meaningful.
The proposed mechanism is interesting: boron appears to increase the rate at which total testosterone converts to free testosterone, rather than boosting total production. Researchers also observed a decrease in estradiol (a form of estrogen) after supplementation. This makes boron particularly relevant for older men, whose levels of the binding protein SHBG tend to rise with age, leaving less free testosterone available.
Tongkat Ali
Tongkat Ali (Eurycoma longifolia) is a Southeast Asian root extract with a growing body of clinical evidence. A systematic review and meta-analysis in the journal Medicina found that it improved serum total testosterone across multiple trials. Dosages in the reviewed studies ranged from 100 to 600 mg daily, taken for anywhere from a few days to six months.
Quality matters here more than with most supplements. Seven of the nine studies in that review used the same freeze-dried water extract standardized to 0.8 to 1.5% eurycomanone, which is the key active compound. If you’re shopping for tongkat ali, look for a product that lists its eurycomanone content in that range. Unstandardized root powders are essentially a guess.
Fenugreek
Fenugreek seed extract contains a mix of saponins, polyphenols, and steroidal compounds that have long been used in traditional medicine for sexual health. In a double-blind, placebo-controlled trial, men taking fenugreek extract saw a 13% increase in total testosterone and a 16.3% increase in the free testosterone index compared to their own baseline values. Those are real numbers, but there’s a catch: when compared directly against the placebo group, the differences didn’t quite reach statistical significance (9% and 11.3% above placebo, respectively).
That means fenugreek likely has a real but small effect, and the results could partly reflect natural fluctuation. It’s a reasonable addition to a broader approach but probably not a standalone solution.
Zinc and Magnesium
Zinc is essential for testosterone production. Your pituitary gland needs it to release luteinizing hormone, which signals the testes to produce testosterone. If you’re deficient in zinc, correcting that deficiency can meaningfully raise testosterone levels. The problem is that most men eating a varied diet aren’t severely deficient.
Preclinical research suggests that combining magnesium, zinc, and selenium produces a stronger hormonal response than any of those minerals alone. In a rat study, the combination group had the highest levels of luteinizing hormone, FSH, and IGF-1 compared to single-mineral groups. The human-equivalent zinc dose in that study was about 30 mg per day, which is close to what you’d find in a ZMA supplement. These are animal data, so the translation to humans isn’t guaranteed, but the biological logic is sound: these minerals serve as cofactors for the enzymes involved in hormone production, and being low in any of them can create a bottleneck.
Vitamin D
Vitamin D is often promoted as a testosterone booster, but the clinical evidence is disappointing. A systematic review and meta-analysis of clinical trials in the journal Andrologia found that vitamin D supplementation had no significant effect on total testosterone across doses ranging from 600 to 4,000 IU daily (and up to 60,000 IU weekly) over periods of 6 weeks to 36 months. Subgroup analyses looking at dosing frequency, duration, and baseline vitamin D levels all came up empty.
Vitamin D is still important for bone health, immune function, and general well-being, and severe deficiency is linked to lower testosterone in observational studies. But based on current trial data, taking a vitamin D supplement specifically to raise testosterone is unlikely to work, even if you start with low levels.
D-Aspartic Acid: Temporary at Best
D-Aspartic Acid (DAA) generated excitement based on early studies showing a short-term testosterone spike. More recent research paints a less optimistic picture. In a study of male boxers taking 6 grams per day for 14 days, testosterone rose by about 15.6% after 9 days of supplementation. But by the following days, levels were no longer significantly different from baseline. The increase in the testosterone-to-cortisol ratio was similarly temporary.
The researchers concluded that DAA supplementation did not cause meaningful beneficial changes in testosterone. This pattern, a brief bump that fades with continued use, makes DAA a poor choice for sustained hormonal support.
A Note on Safety
Natural supplements are generally well tolerated at standard doses, but the testosterone-boosting market has a serious contamination problem. Some products marketed as herbal testosterone boosters have been found to contain undeclared synthetic anabolic steroids. These compounds, particularly those modified to survive digestion (C-17 alpha alkylated steroids), can cause serious liver damage including prolonged bile blockage, liver tumors, and vascular changes within the liver. Ma Huang (ephedra), another ingredient sometimes found in “energy” or “strength” formulations, has been linked to acute liver injury as well.
Stick with reputable brands that use third-party testing, and be skeptical of products promising dramatic results. If a supplement works as well as a pharmaceutical, it probably contains one.
Why Your Baseline Matters Most
The single biggest factor determining whether a supplement will raise your testosterone is where you’re starting from. Men with genuine deficiencies in zinc, magnesium, or vitamin D have the most room for improvement because their hormonal machinery is missing a required input. If your diet is solid, your sleep is consistent, and your mineral status is normal, supplements will produce marginal effects at best.
Before spending money on supplements, it’s worth getting a blood test that includes total testosterone, free testosterone, and SHBG. This gives you an actual number to work with. If you decide to supplement, wait at least 8 weeks before retesting, as that’s the minimum duration used in most positive clinical trials. The American Urological Association recommends re-checking levels 2 to 4 weeks after starting testosterone therapy specifically, but natural supplements work more slowly and need a longer window to show results.
The most evidence-backed options, in rough order of supporting data, are ashwagandha, boron, and tongkat ali. Zinc and magnesium are worth adding if your intake is low. Fenugreek is a reasonable secondary option. Vitamin D and D-Aspartic Acid, despite their popularity, have weak or nonexistent support for this particular goal.