One small study put boron into many testosterone boosters. We look at what it measured, what other research showed, and how much boron is safe.
Boron got its testosterone reputation from a 2011 study of eight men. After a week on 10 mg of boron daily, their free testosterone was higher and their estradiol lower. There was no placebo group, and the study ran just a week. In bodybuilders, a placebo-controlled trial found no testosterone effect. A few milligrams a day is low-risk, adults shouldn't go past 20 mg, and boron is no fix for low testosterone.
Boron is a trace mineral present in fruit, vegetables, nuts, legumes and coffee. Many testosterone boosters contain it because one small 2011 study reported higher free testosterone after a week at 10 mg a day. The study is genuine, but it was tiny, short and uncontrolled, and a lower dose showed no testosterone effect in a placebo-controlled trial of young men.
Honestly, boron might nudge free testosterone and estrogen for a short time. Nobody has shown a meaningful, lasting rise in testosterone, or a benefit men would notice. It's also among the few booster ingredients that has a clear official upper limit, which matters when you combine several products.
The study that most boron marketing leans on came from Naghii and colleagues, in the Journal of Trace Elements in Medicine and Biology in 2011. An abstract of the work describes how it was run. Eight healthy male volunteers took a 10 mg boron capsule. Blood was taken on day 0, over the first day, and again after a week of 10 mg daily.
At the one-week mark, the researchers reported the following:
According to the authors, it was the first human study to show higher plasma free testosterone after boron. That claim is why it is cited so widely.
People often cite the 2015 review "Nothing Boring About Boron" next to it. It is an upbeat narrative review by one author, and the human hormone studies it covers had between 8 and 18 participants. It also gives the Naghii dose inconsistently in different places.
Older research points the other way. In a 7-week trial in Environmental Health Perspectives in 1994, Green and Ferrando gave 2.5 mg of boron daily to 10 male bodybuilders and a placebo to 9 others. Testosterone climbed in both groups, which the authors attributed to training. Boron made no significant difference to testosterone or to anything else they measured.
This trial was small too, and 2.5 mg is below the 10 mg used later. But it did have a placebo group, it ran seven weeks rather than one, and it enrolled young, active men, the very group boron boosters target.
| Naghii et al. (2011) | Green and Ferrando (1994) | |
|---|---|---|
| Participants | 8 healthy men | 19 male bodybuilders |
| Dose | 10 mg a day | 2.5 mg a day |
| Length | 1 week | 7 weeks |
| Placebo group | No | Yes |
| Testosterone result | Free testosterone higher, estradiol lower | Boron had no effect |
A 2019 review of 50 testosterone booster products in the World Journal of Men's Health found boron in roughly a quarter of them. Its authors described the published boron data as mixed: some studies showed a rise, others no change.
No recommended daily amount exists for boron. The NIH Office of Dietary Supplements boron fact sheet says the data weren't strong enough to set one. There is a Tolerable Upper Intake Level (UL), which is the most you should take in a day from all sources combined:
| Age group | Daily upper limit |
|---|---|
| Adults 19 and older, including during pregnancy and breastfeeding | 20 mg |
| Teens 14 to 18, including during pregnancy and breastfeeding | 17 mg |
| Children aged 9 to 13 | 11 mg |
| Children aged 4 to 8 | 6 mg |
| Children aged 1 to 3 | 3 mg |
The limits come from reproductive and developmental effects seen in animals, the fact sheet explains. It estimates that US adults typically get roughly 0.9 to 1.4 mg a day from food, chiefly coffee, milk, apples, beans and potatoes. So a 10 mg supplement delivers about seven to ten times a usual diet, yet it still sits under the adult limit.
Most serious boron poisoning comes from swallowing boric acid or borax, not from supplements. The ODS lists toxicity symptoms including nausea, vomiting, diarrhea, skin flushing, rash and headache, and, in severe cases, kidney injury and convulsions. Long-term data at supplement doses are missing, so staying well below the limit is wiser than hovering near it.
The ODS says boron isn't known to interact in clinically relevant ways with medications, but that reflects limited research, not proof that it's safe. Mention it to your doctor or pharmacist as you would any supplement.
Boron is commonly sold next to zinc and magnesium, and the reasoning for all three is alike. Fixing a shortfall may help, but megadosing on top of normal intake probably does little. See our guide to the link between zinc and testosterone for when zinc matters, and our magnesium supplement guide for forms and sensible doses.
Maybe you're considering boron because you feel tired or flat, or your sex drive has dropped. Find the cause first. These symptoms overlap with sleep problems, stress, weight and many medical conditions. Our article on low testosterone symptoms in men describes what proper testing involves. A supplement can't fix diagnosed testosterone deficiency, and using one in place of testing can delay finding something important.
If you still want to try boron, keep these points in mind:
Eight men in the much-quoted boron study had higher free testosterone and lower estradiol after one week at 10 mg a day. It's an intriguing signal, but nobody was on placebo, and a placebo-controlled trial in bodybuilders found no testosterone effect. A few milligrams a day looks reasonably safe, and adults have a clear upper limit of 20 mg. Treat boron as, at most, a cheap, low-stakes experiment and not a remedy for low testosterone.