Do ZMA and zinc really boost testosterone? Lore vs research
Published: 2026-06-24
Written by: Hirotsugu YoshimuraReviewed by: Tomonobu Someda
'Take ZMA (zinc, magnesium, vitamin B6) or zinc and your testosterone — and your gains — will rise.' We line up this supplement-aisle staple against the research.
Let the data settle it.
Does ZMA raise testosterone in people who train?
What's said
サプリ広告・一般的な通説
ZMA naturally raises testosterone, so taking it boosts both strength and muscle growth.
What research says
- In an 8-week RCT of 42 resistance-trained men, blood zinc and magnesium rose, but there were no significant changes in testosterone or IGF-1, and no evidence that ZMA directly improved strength or muscle.
In well-nourished trained lifters, the 'test-booster' claim isn't supported — though this rests on a single small RCT and should be read with that caveat.
Does zinc itself raise testosterone?
What's said
一般的な通説
Zinc is the testosterone mineral — supplement it and anyone's levels go up.
What research says
- In zinc-deficient older men, supplementation roughly doubled testosterone (a return toward normal).
- But in men with adequate zinc, extra zinc did not raise levels.
- The sample was small (n=40).
Zinc corrects a deficiency rather than 'boosting' beyond normal. If you're already replete, more won't push it higher.
So is there any point in taking zinc or magnesium?
What's said
反動的な通説
If it doesn't raise testosterone, it's a waste of money.
What research says
- Even if it disappoints for testosterone, zinc is linked to better immune markers (NK-cell activity, T-cell proliferation), and magnesium has trials on sleep quality.
- Their value for correcting a deficiency is a separate question.
Weak as a 'test booster.' But as a way to cover a dietary shortfall of these minerals, it's reasonable.
Related supplements
PR
Testosterone normalization in zinc-deficient individuals (deficiency correction)
The links below include affiliate links (PR).
Related research
- Effect of zinc and magnesium supplementation on testosterone and insulin-like growth factor-1 in resistance-trained men2009
- Effects of Zinc Supplementation on Testosterone Levels and Immune Function1996
- The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial2012
Sources
Published: 2026-06-24
Written by
Hirotsugu YoshimuraFounder of BODYDATA / CEO of INVOLVE
I don't pick things because they "seem good." I check the data first, then test it with my own body.
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Reviewed by: Tomonobu Someda
Content reviewed from the perspective of coaching practice and supplement-industry experience