Testosterone boosters promise a lift, but most ingredients were never tested for it

Key takeaways

• When USC researchers reviewed 50 top online testosterone boosters, 90% promised to raise testosterone, yet more than 6 in 10 of their 109 ingredients had never been studied for that effect¹².
• Thirteen of the 50 products held more zinc, niacin or magnesium than the daily upper limit for that nutrient¹.
• An independent 2026 review of fenugreek trials, most paid for by extract makers, found only a small, very uncertain rise in total testosterone and concluded the evidence doesn’t support booster claims⁴.
• Tribulus, D-aspartic acid and DHEA have been tested in men and mostly failed to raise testosterone⁷⁸¹⁰.
• In a 2013 review of 24 studies, men with obesity who lost weight saw their testosterone rise, and weight-loss surgery raised it about three times as much as dieting¹⁴.

For a study published in 2019, a team led by urologist Mary Samplaski at the Keck School of Medicine of USC did what a curious shopper might do. They typed “testosterone booster” into Google and kept the top 50 results².

Then they looked up the science behind every ingredient, work that appeared in the World Journal of Men’s Health¹. The 50 products held 109 different ones, an average of 8.3 per bottle¹. For 61.5% of those ingredients, the team found no published data on testosterone at all¹.

About a quarter, 24.8%, had at least one study showing testosterone rose. Another 18.3% had data showing no change, and 10.1% had data showing it fell¹. Some ingredients had studies pointing in more than one direction.

Yet 90% of the products claimed to boost testosterone¹. Many also packed vitamins far past daily needs. The typical product held 1,291% of the recommended amount of vitamin B12 and 808% of the amount for B6¹. Thirteen went over the upper limit for zinc, niacin or magnesium¹.

In Samplaski’s view, much of what fills these bottles is ordinary vitamins and minerals with no effect on testosterone, sold on the strength of marketing².

The wish behind these bottles is reasonable. Plenty of men want more energy, drive and strength, and would rather try a plant than a prescription. This article covers how the most common ingredients rate, what the risks are, and what reliably raises testosterone. Our ashwagandha article covers that herb’s testosterone trial, so this one covers the rest of the shelf.

Fenugreek: a kitchen seed with a small, uncertain signal

Fenugreek turns up in cooking, traditional remedies and today’s supplements⁴. The National Center for Complementary and Integrative Health (NCCIH) lists traditional uses such as menstrual cramps and constipation, and notes it’s promoted for diabetes and breast milk supply⁵. Its fact page doesn’t mention testosterone⁵.

In August 2026, a team writing in Frontiers in Nutrition published a new review of fenugreek and testosterone⁴. They found 13 placebo-controlled trials. Eight measured testosterone as a main result, with 637 men in all⁴. Most used branded extracts at 500 to 600 milligrams a day for 8 to 12 weeks⁴.

Pooling six trials, total testosterone rose slightly, but the reviewers rated their certainty in that result as very low⁴. Free testosterone, the unattached share in the blood, showed no steady benefit⁴. The authors cautioned that a modest bump in the total doesn’t guarantee a lasting gain in the free share⁴.

Now look at who paid. Extract makers, including Indus Biotech and Gencor Pacific, sponsored many of the trials, and none of the 13 earned an overall low-risk-of-bias rating⁴. None was built around men with diagnosed low testosterone, so the review can’t say whether fenugreek helps them⁴. The reviewers reported no funding or conflicts of their own, and they concluded that the evidence doesn’t support testosterone-boosting claims⁴.

An earlier review in Advances in Nutrition looked at 32 trials of 13 herbs published from 2001 to 2019³. Nine found a significant rise in testosterone, and fenugreek and ashwagandha had the most positive results³. But only 6 of the 32 trials were rated at low risk of bias, and half enrolled men under 40³.

Fenugreek’s side effects include diarrhea, nausea and, in large doses, a harmful drop in blood sugar, NCCIH says⁵. It can trigger allergic reactions, some serious. It isn’t safe during pregnancy in amounts above those in food⁵.

Tongkat ali: bigger effects, mostly from one maker’s extract

Eurycoma longifolia, also called tongkat ali, Malaysian ginseng or pasak bumi, has long been used for male sexual problems and infertility⁶. Most of its active compounds sit in the root⁶.

A 2022 review in the journal Medicina pooled five randomized trials with 232 men⁶. Testosterone rose, with a clear effect in men with hypogonadism, the medical term for low testosterone, and a weaker one that wasn’t statistically significant in healthy men⁶.

Results varied widely from trial to trial. Statistical tests also flagged possible publication bias, meaning the studies that reached print may not represent all the research done⁶. The review reported its result on a standardized scale, so it gives no average gain in the units on a lab report.

Most of the evidence comes from a single product: seven of the nine studies tested Physta, a water extract made by the company Biotropics⁶. Daily doses spanned 100 to 600 milligrams, and the trials lasted anywhere from three days to six months⁶. The review didn’t describe who sponsored the trials. Its authors reported no outside funding and no conflicts⁶.

Product quality is a second problem. The review cites a check of 41 tongkat ali products from Malaysia: 24 contained eurycomanone, the plant’s marker compound, but only 11 of those fell in the recommended range, and 9 had more⁶. A bottle on your shelf may not match the extract that was tested.

Side effects were rarely reported; one trial noted stomach upset and itching⁶. With so few small trials, long-term safety remains an open question.

Tribulus, D-aspartic acid and DHEA mostly failed their tests

Tribulus. A 2014 systematic review of Tribulus terrestris in the Journal of Dietary Supplements found 11 qualifying studies⁷. Testosterone rose in some animal studies, but in people it rose only when tribulus was part of a mix of ingredients⁷. Taken alone, it didn’t appear to work, and the authors called marketing claims unsubstantiated⁷.

The NIH Office of Dietary Supplements (ODS) agrees: a few small, short trials found no effect on strength, lean mass or sex hormones⁸. A 2025 crossover trial in 13 student athletes found a twist. During four weeks off training, resting testosterone held steady on tribulus while it fell on placebo, yet strength, aerobic fitness and body composition didn’t benefit⁹.

D-aspartic acid. A 2017 review found 23 animal studies and only 4 in people¹⁰. One human study saw testosterone rise about 42% after 12 days of 3.12 grams a day¹⁰. Two found no change. In the fourth, 3 grams a day did nothing, while 6 grams a day lowered both total and free testosterone¹⁰.

Those studies lasted 12 to 28 days and were small, and the reviewers called the human results inconsistent¹⁰.

DHEA. This hormone from the adrenal glands can be converted by the body into testosterone and estradiol, a form of estrogen⁸. In 40 male weightlifters averaging 48 years old, 100 milligrams a day for 12 weeks didn’t change testosterone, strength or lean mass⁸. A trial of 150 milligrams a day in 20 young men starting weight training found no benefit either⁸.

The NCAA and the World Anti-Doping Agency ban DHEA⁸. In women, months of use raised testosterone, which can cause acne and facial hair⁸. Our article on supplement cautions in autoimmune disease covers DHEA in lupus.

Zinc and boron fix shortfalls, but they don’t stack up

Zinc is among the most common booster ingredients². Men need 11 milligrams a day, and the upper limit for adults is 40 milligrams, counting food and supplements together¹¹. The ODS zinc fact sheet, updated in January 2026, doesn’t tie zinc supplements to testosterone¹¹.

People more likely to run short include those with digestive disorders or past weight-loss surgery, vegetarians and vegans, and people with alcohol use disorder¹¹. For them, a test and a plan make more sense than a booster.

Picture a man who takes a booster with 30 milligrams of zinc and a multivitamin with 11. By our math, that’s 41 milligrams before he eats anything, already past the limit. At 50 milligrams or more a day for weeks, zinc can lower HDL cholesterol, weaken immunity and block copper absorption¹¹. Our zinc article explains the copper problem.

Boron has no recommended daily amount, and the adult upper limit is 20 milligrams¹². Adults typically get about 1 to 1.5 milligrams a day, with coffee, milk, apples, beans and potatoes among the main food sources¹². Prune juice, avocado and raisins are rich sources¹². The ODS boron fact sheet reports no findings on boron and testosterone¹².

Vitamin D shows up in many formulas too. Our vitamin D article covers who needs it.

Some “boosters” carry an actual steroid

On December 12, 2025, the FDA sent a warning letter to Musclepower Enterprise, doing business as Monster King and GE Labs, in Madison, Wisconsin¹³. One product, Ykarine, was marketed as a SARM, short for selective androgen receptor modulator¹³. Its label called it a dietary supplement¹³.

FDA lab testing found trendione, an anabolic steroid, that wasn’t on the label¹³. The agency called the products unapproved new drugs¹³. It tied anabolic steroids to serious liver injury, kidney damage, heart attack, stroke and blood clots in the lungs and legs, and SARMs to liver toxicity and a higher risk of heart attack and stroke¹³.

That letter fits a long pattern. Our article on hidden drugs in herbal products covers years of FDA findings in muscle-building products, and our risk-scoring article covers a lab test of SARM products. If a booster hides doses in a proprietary blend, our blend article shows the math that can expose it.

What reliably raises testosterone: weight, sleep and the real cause

The best-documented natural lever isn’t in a bottle. In 2013, researchers writing in the European Journal of Endocrinology reviewed 24 studies of men with obesity who lost weight through a low-calorie diet or bariatric surgery¹⁴. Testosterone rose significantly with both¹⁴.

By our math from the abstract’s figures (8.73 versus 2.87; the abstract gives no units), the average rise after surgery was about three times the rise after dieting¹⁴. The more weight men lost, the more testosterone climbed, and gains were larger in younger men without diabetes¹⁴. Estradiol fell at the same time¹⁴.

Sleep matters too. Our testosterone article describes a small study in which a week of short sleep lowered young men’s testosterone, and it lists the conditions, medicines and habits that can push levels down in reversible ways.

That’s the natural-health principle at its best: find the cause and treat it. If weight, sleep, alcohol or a medicine is dragging your level down, fixing that may help more than any booster, and it helps the rest of your body too. Samplaski’s advice was to ask a doctor or a nutrition expert rather than guess².

The T-booster ingredient scorecard

Our own scorecard, built from the sources cited.

Ingredient	Dose tested	Best evidence	Who funded	Rating
Fenugreek seed extract	Mostly 500–600 mg a day for 8–12 weeks4	13 trials, none at low risk of bias: small, very uncertain total rise; free testosterone unchanged; independent reviewers say claims unsupported4	Mostly extract makers4	Not enough evidence
Tongkat ali root extract	100–600 mg a day, 3 days to 6 months6	5 trials, 232 men: clearer rise in men with low testosterone6	7 of 9 studies used one firm’s extract; sponsors not described6	Promising but early
Tribulus	Varied; the 2025 trial used 20 mg per kg of body weight three times a day for 4 weeks9	No rise when taken alone; one small trial saw levels hold steady during detraining, with no performance gains789	Not stated in sources	Evidence says no, or unsafe
D-aspartic acid	3–6 g a day for 12–28 days10	One of four human studies found a rise; 6 g a day lowered it10	Not stated in sources	Evidence says no, or unsafe
DHEA	100–150 mg a day for 6–12 weeks8	No testosterone or strength gain in two trials in men8	Not stated in sources	Evidence says no, or unsafe
Zinc, if you’re not deficient	Men need 11 mg a day; limit 40 mg11	Not tied to testosterone by ODS11	Not applicable	Not enough evidence
Boron	Not tested for testosterone; supplements hold 0.15–6 mg; limit 20 mg12	No testosterone studies described by ODS12	Not applicable	Not enough evidence
Products sold as SARMs or steroid alternatives	Not applicable	FDA found a hidden anabolic steroid13	Not applicable	Evidence says no, or unsafe
Weight loss for men with obesity	Diet or bariatric surgery14	24 studies: testosterone rose, more with more weight lost14	Not shown	Strong evidence

When to get help

Before you try a booster, check with a pharmacist or clinician if you take any medicine. Zinc can reduce absorption of quinolone and tetracycline antibiotics and of penicillamine, and thiazide water pills raise zinc losses¹¹. Large doses of fenugreek may drop blood sugar too far, and NCCIH advises talking with a provider first if you take medicines⁵.

If you or your partner could be pregnant, know that fenugreek isn’t considered safe in pregnancy beyond food amounts⁵.

If you think your testosterone is low, get evaluated rather than guessing, as Samplaski advised². Our testosterone article explains how urologists diagnose low testosterone and why one test isn’t enough.

If you think a supplement harmed you, the FDA directs consumers to report it through its Safety Reporting Portal¹⁵. Keep the bottle and its lot number.

Questions readers ask

The bottom line

Most testosterone boosters sell a promise their ingredients were never tested to keep. Tongkat ali has small trials, mostly of one company’s extract, with modest results. Fenugreek’s maker-funded trials didn’t convince independent reviewers, and tribulus, D-aspartic acid and DHEA have largely failed. Extra zinc, boron and B vitamins add little but cost, and sometimes risk.

The strongest natural evidence points to the body itself. For men with obesity, weight loss raises testosterone, and fixing sleep, alcohol or a medicine may help more than any capsule. If your energy or drive has dropped, a proper evaluation will tell you more than a label will.

Related reading

• Testosterone’s heart scare has eased, but its fertility catch has not
• Ashwagandha lowers a stress hormone, and regulators are now splitting root from leaf
• Some herbal pills hide prescription drugs, and others swap out the herb
• Some Proprietary Blends Hide Stimulant Doses. Simple Math Can Expose Weak Ones
• Adrenal fatigue isn’t a diagnosis, but your exhaustion still deserves one

Sources

1. Clemesha CG, Samplaski MK, et al. “‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature.” World Journal of Men’s Health, 2020, pages 115–122 (published online June 2019; abstract via the WHO Global Index Medicus/BVS; author names from the Sexual Medicine Society of North America’s summary, August 13, 2019). pesquisa.bvsalud.org and smsna.org
2. Wolfson W. “Are testosterone-boosting supplements effective? Not likely, says new study.” Keck School of Medicine of USC news release, June 26, 2019. keck.usc.edu
3. Smith SJ, Lopresti AL, Teo SYM, Fairchild TJ. “Examining the Effects of Herbs on Testosterone Concentrations in Men: A Systematic Review.” Advances in Nutrition, volume 12, issue 3, pages 744–765, dated 2020 in the Murdoch University record. researchportal.murdoch.edu.au
4. Yang P, Niu Z, Guo J, Huang T, Chang D, Huang X. “Effects of oral fenugreek-derived preparations on testosterone-related outcomes in adult men: a systematic review and meta-analysis of randomized placebo-controlled trials.” Frontiers in Nutrition, 2026;13:1903508, published August 19, 2026. frontiersin.org
5. National Center for Complementary and Integrative Health. “Fenugreek: Usefulness and Safety.” NIH, last updated February 2025. nccih.nih.gov
6. Leisegang K, Finelli R, Sikka SC, Panner Selvam MK. “Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials.” Medicina, 2022;58(8):1047. pubmed.ncbi.nlm.nih.gov
7. Qureshi A, Naughton DP, Petroczi A. “A systematic review on the herbal extract Tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect.” Journal of Dietary Supplements, 2014;11(1):64–79 (Kingston University record). pubmed.ncbi.nlm.nih.gov
8. NIH Office of Dietary Supplements. “Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals.” National Institutes of Health, accessed October 2026. ods.od.nih.gov
9. Ataei L, Giannaki CD, Petrou C, Aphamis G. “Tribulus terrestris failed to improve exercise performance and body composition following a detraining period.” Sport Sciences for Health, 2025;21(2):747–757 (University of Nicosia record). pure.unic.ac.cy
10. Roshanzamir F, Safavi SM. “The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review.” Published January 2017 by the Research and Clinical Center for Infertility, Yazd Shahid Sadoughi University of Medical Sciences (ProQuest record; journal name not shown on the record). pubmed.ncbi.nlm.nih.gov
11. NIH Office of Dietary Supplements. “Zinc: Fact Sheet for Health Professionals.” National Institutes of Health, updated January 6, 2026. ods.od.nih.gov
12. NIH Office of Dietary Supplements. “Boron: Fact Sheet for Health Professionals.” National Institutes of Health, updated June 9, 2022. ods.od.nih.gov
13. U.S. Food and Drug Administration. Warning letter to Musclepower Enterprise Ltd. dba Monster King and GE Labs, MARCS-CMS 719339, December 12, 2025. fda.gov
14. Corona G, Rastrelli G, Monami M, et al. “Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis.” European Journal of Endocrinology, 2013;168(6):829–843 (University of Florence record). flore.unifi.it
15. U.S. Food and Drug Administration. “How to Report a Non-Emergency.” Content current as of March 29, 2018. fda.gov