Testosterone supplements: what works and what your blood shows

Testosterone supplements raise your testosterone almost only when they top up a deficiency. In trained men with normal values, the trials measured close to nothing. Of 50 boosters that researchers screened in 2020, 24.8 percent had data showing a rise. In 10.1 percent, testosterone actually fell (Clemesha 2020, PMID 31385468).

What strikes me as a training partner? The ten pages above this one nearly all sell a tub. I do not sell tubs.

I want to know what measurably changes in your body. And whether that is worth 40 euros a month.

So below are the trials per ingredient, converted to the unit on a Dutch lab report. And a simple measuring plan to check it on yourself.

What is a testosterone supplement, really?

A testosterone supplement contains no testosterone. It is a mix of vitamins and minerals, herbs or amino acids. It is meant to support your own production of testosterone. Testosterone itself is a prescription medicine.

That difference matters. Taking or injecting testosterone without a prescription is a medical route with its own risks. It falls outside this article. If you are considering testosterone therapy, first read which blood values to track on TRT.

Testosterone supplements in the shop fall roughly into three groups. Nutrients such as zinc, magnesium and vitamin D. Herbs such as tribulus terrestris, maca, tongkat ali, ashwagandha and shilajit. And amino acids such as D-aspartic acid.

A test booster from the sports shop is the same product under a different name. Usually a mix with ingredients such as tribulus, zinc, D-aspartic acid and a vitamin D3.

Each group has a different story. That story is below, ingredient by ingredient.

Is it good to take testosterone?

Taking testosterone without a medical reason is not a supplement choice but a medicine choice. With a proven deficiency, a doctor can prescribe it, with blood monitoring. Without a deficiency, extra testosterone suppresses your own production, and that does not come back by itself.

A booster from the shop does not do that. In most cases it does nothing else either. That is the honest answer.

Which supplements can raise testosterone?

Zinc and vitamin D can raise testosterone if you are deficient in them. Ashwagandha, tongkat ali and shilajit showed a rise in small trials in specific groups. Tribulus terrestris, maca, ZMA and D-aspartic acid did nothing measurable in healthy, trained men.

That is the short version of more than twenty years of research. The long version is in the table, with the trial, the group and the number.

Read the third column twice. Vitamin D worked in overweight men on a weight-loss programme. Zinc worked in older men with a deficiency. Tongkat ali worked in men who already had low testosterone.

The trained young man with normal values does not appear in the winning rows. He is in the rows with tribulus, ZMA and D-aspartic acid. There nothing moved, or it moved the wrong way.

Ashwagandha is the exception, and it comes with a caveat. The Dutch RIVM has advised against ashwagandha supplements since 5 March 2024, after reports of liver damage. What the trials did measure is in ashwagandha and testosterone.

What is the best way to raise testosterone?

There is no best remedy, and whoever names one is usually selling it. The best result in the trials comes from boring things. Sleep, a lower body fat percentage, less alcohol and heavy strength training. A natural testosterone booster from a tub does not come close.

Sleep plays a bigger role than any supplement. Ten young men slept five hours a night for a week. Their daytime testosterone fell by 10 to 15 percent (Leproult 2011, PMID 21632481). What that does to your values is in what poor sleep does to your hormones.

Excessive alcohol use suppresses testosterone production and raises estradiol. A couple of beers on Saturday do little. Three every night do something, and you see it in your values.

Fat matters too. Fat tissue converts testosterone into estrogen through the enzyme aromatase. A lower body fat percentage is therefore often a bigger lever than any herb.

Healthy fats in your food belong there, because cholesterol is the building block of testosterone. An extremely low-fat diet is therefore a bad idea for your hormones. What does and does not work naturally is in increasing testosterone naturally.

What is the best testosterone supplement for men?

The question of which testosterone supplement is best has a different answer per situation. For most men the answer is: none. For a smaller group the answer is a nutrient they are short of.

I will set it out per situation. Not as advice to take anything, but to make the table above readable.

• Your vitamin D is low, which is common in a Dutch winter. Then the Pilz trial is relevant to you. Supplements usually contain vitamin D3, the same form your skin makes. Read vitamin D deficiency in athletes.
• Your zinc is low, for instance with heavy sweating and little meat: Prasad is then your trial. Read zinc and testosterone.
• You are stressed and sleeping badly: ashwagandha is the best studied, but the RIVM advises against it. Weigh that yourself.
• You are 45 or older with normal values. The shilajit trial is the only one in that group. Read what shilajit does.
• You are young, trained and your values are normal: no supplement has shown a rise in you.

What strikes me about that list: every line starts with a blood value. Without that number you choose blind.

If you still go looking for the best testosterone booster, read the label first. 'Contributes to normal testosterone levels' is the only claim EFSA has authorised, and it applies to zinc alone. Lines such as 'a herb that stimulates your testosterone' are marketing. So is 'zinc in a highly absorbable form'.

Testosterone deficiency: complaints and numbers

A testosterone deficiency brings complaints such as fatigue, low libido, reduced muscle mass and more belly fat. Your sexual health in a wider sense suffers too. Your bones notice it too, because testosterone plays an important role in strong bones. But each of those complaints has ten other causes as well.

That is why you need the number. Four large cohorts in Europe and the United States were harmonised for this. The lower limit for healthy young men was 9.2 nmol/l, the upper limit 31.8 (Travison 2017, PMID 28324103). Dutch labs use their own reference values, usually in the same neighbourhood.

A number below the lower limit is not yet a diagnosis. The same man's testosterone differs between morning and afternoon. And between a good night and a bad one. Two morning readings say more than one.

Imagine two men both measuring 12 nmol/l. One is 24, sleeps five hours and trains six days a week. The other is 52 and feels fine. Same number, two different stories.

The first probably gains more from sleep than from any tub. What a low number does and does not mean is in testosterone symptoms and blood values. Also read low testosterone in men.

What a supplement does to your blood values, measured

This is the part that appears on no sales page. Want to know what a supplement does to your hormonal balance? Then you measure before and after. The same values, the same time of day, the same conditions.

This is what that measuring plan looks like.

Have blood drawn in the morning between 7 and 10, after a normal night. Fasting is usually not needed for testosterone. Testosterone peaks then, and that is what reference values are based on. A reading after a night shift or a heavy training week says little.

With us, measuring means a blood draw from the arm at one of the laboratories we work with. Your result arrives online, with an assessment from a BIG-registered doctor. No home kit, no finger prick.

The testosterone test measures your total testosterone; the hormone panel adds free testosterone and SHBG. The other values in the table are measured separately via the biomarker pages.

Side effects, and what the RIVM, the NVWA and EFSA say

The boosters themselves are rarely dangerous, but they are often absurdly high-dosed. The 50-product analysis found a median 807 percent of the recommended vitamin B6 per daily dose. For zinc it was 272 percent (Clemesha 2020, PMID 31385468). Upper limits exist for B6 and zinc, and they are that easily exceeded.

Too much zinc lowers your copper and your immune function over time. Too much B6 can cause nerve complaints. More is really not better here.

With the herbs it is different. The RIVM has advised against ashwagandha since March 2024.

The NVWA found tongkat ali at 10 companies in 2024. EFSA calls the substance genotoxic, and its sale in the EU is banned. Why that is so is in tongkat ali side effects.

The Dutch Voedingscentrum keeps it simple. People who eat a healthy, varied diet do not need supplements as a rule. For most boosters, that is also what the trials say.

D-aspartic acid deserves a sentence of its own. At 6 grams a day, total and free testosterone fell in trained men. That happened within two weeks (Melville 2015, PMID 25844073). It is in many boosters, and there it works the wrong way.

Frequently asked questions

What is the best testosterone booster?

There is no best testosterone booster. The nutrient you are short of is the only supplement that works for you. And you only know that after a measurement.

Is a test booster different from a testosterone supplement?

No. Test booster is the shop name for the same kind of product. Usually herbs, zinc and vitamin D3. The name says nothing about the evidence.

Does a natural testosterone booster work?

A natural testosterone booster with tribulus, maca or D-aspartic acid did nothing in healthy men. Testosterone stayed flat in the trials. Maca did raise libido, without touching the hormones.

What you can do with this

My line after twenty years of trials: a testosterone supplement is not a booster but a top-up. If it works, you had a deficiency. If it does not, you had normal values and the tub was unnecessary.

That is why I would always measure first. It costs one morning and it decides whether the rest of this article applies to you. Measure twice, and you also know whether the supplement did anything, instead of hoping it did.

The five supplements that most often sit next to the protein shakes I have worked out separately. They are maca powder, shilajit, tongkat ali, ZMA and tribulus terrestris. A broader overview is in 9 supplements for athletes.

If a value is off, discuss it with your GP and mention which supplements you take. Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

References

• Clemesha CG, Thaker H, Samplaski MK. 'Testosterone Boosting' Supplements Composition and Claims Are not Supported by the Academic Literature. World J Mens Health. 2020 (PMID 31385468).
• Pilz S, Frisch S, Koertke H, et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 (PMID 21154195).
• Prasad AS, Mantzoros CS, Beck FW, et al. Zinc status and serum testosterone levels of healthy adults. Nutrition. 1996 (PMID 8875519).
• Wankhede S, Langade D, Joshi K, et al. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr. 2015 (PMID 26609282).
• Lopresti AL, Drummond PD, Smith SJ. A randomized, double-blind, placebo-controlled, crossover study examining the hormonal and vitality effects of ashwagandha (Withania somnifera) in aging, overweight males. Am J Mens Health. 2019 (PMID 30854916).
• Tambi MI, Imran MK, Henkel RR. Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia. 2012 (PMID 21671978).
• Pandit S, Biswas S, Jana U, et al. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia. 2016 (PMID 26395129).
• Neychev VK, Mitev VI. The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men. J Ethnopharmacol. 2005 (PMID 15994038).
• Rogerson S, Riches CJ, Jennings C, 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. J Strength Cond Res. 2007 (PMID 17530942).
• Gonzales GF, Córdova A, Vega K, et al. Effect of Lepidium meyenii (Maca) on serum reproductive hormone levels in adult healthy men. J Endocrinol. 2003 (PMID 12525260).
• Wilborn CD, Kerksick CM, Campbell BI, et al. Effects of zinc magnesium aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism. J Int Soc Sports Nutr. 2004 (PMID 18500945).
• Melville GW, Siegler JC, Marshall PW. Three and six grams supplementation of d-aspartic acid in resistance trained men. J Int Soc Sports Nutr. 2015 (PMID 25844073).
• Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011 (PMID 21632481).
• Travison TG, Vesper HW, Orwoll E, et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies in the United States and Europe. J Clin Endocrinol Metab. 2017 (PMID 28324103).
• RIVM. RIVM raadt gebruik producten met kruiden Huperzia serrata, Tabernanthe iboga of ashwagandha af. 5 March 2024.
• NVWA. Inspectieresultaten tongkat ali (Eurycoma longifolia Jack) 2024. nvwa.nl.
• Voedingscentrum. Voedingssupplementen. voedingscentrum.nl.