Ferrando · International journal of sport nutrition 1993 · randomized controlled trial · n=19

The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders.

Cited 41 times in the scientific literature.

Level 2 - randomized trial

Randomized controlled trial

PubMed 8508192 · doi:10.1123/ijsn.3.2.140 · record verified 2026-08-29

What was done

Nineteen male bodybuilders (ages 20–27) were randomized to receive either 2.5 mg of oral boron daily (n = 10) or a placebo (n = 9) for 7 weeks. Total and free plasma testosterone, plasma boron levels, lean body mass, and strength (1-RM squat and 1-RM bench press) were evaluated on Days 1 and 49.

What was found

Plasma boron significantly increased in the boron group from 20.1 ± 7.7 ppb to 32.6 ± 27.6 ppb, while the control group decreased from 15.1 ± 14.4 ppb to 6.3 ± 5.5 ppb (p < 0.05). Analysis of variance indicated no significant effect of boron supplementation on total testosterone, free testosterone, lean body mass, 1-RM squat, or 1-RM bench press. Both groups demonstrated significant baseline-to-posttest increases in total testosterone, lean body mass, squat, and bench press over the 7 weeks.

Why it matters

This study provides randomized controlled evidence that boron supplementation does not enhance testosterone production, muscle mass, or strength in resistance-trained males beyond the effects of training itself.

Limits

The sample size was very small (n = 19), which substantially limits statistical power to detect small differences. The abstract does not report whether blinding was implemented, does not describe dietary controls or specific training regimens, and only tested a single dose (2.5 mg/day) in young males.

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