Does Boron Raise Testosterone? What the Trials Actually Show
Educational summary — not medical advice. Boron is not an approved or proven treatment for low testosterone; anyone with symptoms of low testosterone should see a clinician for testing, not self-treat with a supplement. This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
The honest answer
Not nothing, but not what the ads say. One small trial (n=8, untrained men, 1 week, 10 mg/day) found free testosterone rose ~28% and estradiol fell ~39% (Naghii 2011). A longer, more rigorous randomized trial (n=19 trained bodybuilders, 7 weeks, 2.5 mg/day) found no effect on testosterone, lean mass, or strength (Ferrando & Green 1993). Give both trials equal weight: a small short-term signal in one narrow population, not replicated in athletes.
Two trials, read side by side
Boron's testosterone reputation rests almost entirely on a single small study. It's worth reading it next to the one rigorous attempt to test the same idea in a more realistic population — because the honest picture only comes from holding both up at once, not citing the positive one alone.
| Study | Design | Dose & duration | Result |
|---|---|---|---|
| Naghii 2011 PMID 21129941 | n=8 healthy, untrained men | 10 mg/day, 1 week | Free testosterone +~28% (11.83→15.18 pg/mL, p≤0.02); estradiol −~39% (p≤0.01); SHBG, hs-CRP, TNF-α all decreased |
| Ferrando & Green 1993 PMID 8508192 | Randomized controlled trial, n=19 trained bodybuilders | 2.5 mg/day, 7 weeks | No effect on total or free testosterone, lean mass, or strength beyond training alone |
Both trials are small by modern standards, and neither has been repeated at a larger scale since. The honest conclusion isn't "the null trial proves boron does nothing" any more than it's "the positive trial proves boron works" — it's that the one clean signal we have failed to show up in the population (trained athletes) and longer timeframe (7 weeks vs 1) most relevant to anyone actually buying a testosterone supplement.
Why the two results might disagree
Several genuine differences separate these trials, and honestly, we don't know which one (if any) explains the gap. Dose: Naghii used 10 mg/day, four times the 2.5 mg/day in Ferrando & Green. Duration: one week versus seven — long enough for training adaptations to dominate in the second trial, too short for anything but an acute effect in the first. Training status: untrained men may have more room for a mineral intervention to move hormone markers than trained bodybuilders already pushing adaptation through resistance exercise. Sample size: 8 people is small enough that a single outlier can meaningfully move a percentage change. Any of these could be the real explanation — or the positive result could simply be a false positive that a larger, better-controlled trial would resolve. That uncertainty is the actual state of the evidence, not a detail to gloss over.
If you take it anyway
If you want to try boron with realistic expectations, dose to the 3 mg/day level with the broader base of human safety and mineral-metabolism data behind it (see the dosage guide), rather than chasing the 10 mg/day used in the unreplicated hormone trial — there's no evidence that dose is more effective for this purpose, only that it's the dose one small trial happened to use. Give it realistic weight alongside the rest of your routine: sleep, resistance training, and body composition move testosterone far more reliably than any single mineral supplement, boron included. And if you have symptoms of low testosterone, get tested — a supplement is not a substitute for diagnosis. If you are pregnant or breastfeeding, stay well under the tolerable upper limit and talk to your clinician first (see the safety note).
Frequently asked questions
Does boron raise testosterone?
A small signal exists (n=8, 1 week, +~28% free-T) that a more rigorous 7-week RCT in trained bodybuilders (n=19) did not replicate. Fair summary: a small short-term signal, not replicated in athletes — not a proven boost.
Why do the two trials disagree?
Real differences in dose (10 mg vs 2.5 mg), duration (1 week vs 7 weeks), training status, and sample size (8 vs 19) could each explain the gap — or the positive result could be a false positive. It's genuinely unresolved.
Should I take boron to boost testosterone?
Set expectations low — the only positive result is unreplicated and small, while the more rigorous trial in athletes found nothing. If you take it, dose at 3 mg/day (the safety-and-mineral-data dose), not the unreplicated 10 mg hormone-trial dose.
What did the positive trial measure?
Naghii 2011: 8 men, 10 mg/day for 1 week. Free testosterone +~28%, estradiol -~39%, SHBG/hs-CRP/TNF-alpha down. Real changes in a tiny, short, unreplicated sample.
Related
- Boron: what it is & who it's for
- Boron dosage guide — the 3 mg dose vs the 20 mg upper limit
- Boron for bone health — the mineral-retention evidence, honestly framed
- Tongkat Ali for Testosterone — a better-studied testosterone-marketed supplement
- Does Saw Palmetto Work? — another men's-health category where the rigorous trials found no effect
Sources
- Naghii MR, et al. "Boron administration combined with strenuous physical activity affects rapid indices of free testosterone." J Trace Elem Med Biol. 2011. PMID: 21129941
- Ferrando AA, Green NR. "The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders." Int J Sport Nutr. 1993. PMID: 8508192