What the evidence says raises or protects testosterone naturally, sleep, strength training, vitamin D, losing excess weight, and, just as usefully, what it says does not.
This systematic review and meta-analysis set out to see whether vitamin D supplements raise testosterone or related markers in men. It pooled randomized trials measuring total testosterone, SHBG (sex hormone-binding…
This study looked at whether vitamin D3 supplementation improves hormone levels and semen quality in infertile men. It pooled data from six randomized controlled trials involving 945 men, measuring changes…
This meta-analysis (a study that statistically pools many earlier studies) looked at how body mass index (BMI, a weight-for-height number used to flag over- or under-weight) relates to sperm quality…
This systematic review and meta-analysis set out to assess whether coenzyme Q10 (CoQ10) supplementation improves semen quality and male hormone levels. It pooled data from eight randomized controlled trials involving…
This study set out to clarify how bisphenol A (BPA, a chemical used in food packaging and container linings) affects men's reproductive health. It pooled 18 studies that measured BPA…
This meta-analysis set out to measure how much testosterone men with obesity get back when they lose weight, comparing low-calorie diets with bariatric surgery. It pooled 44 studies covering 1,774…
This meta-analysis set out to examine how alcohol intake affects male reproductive health by looking at semen quality, antioxidant levels in semen, sperm DNA damage, and sex hormones. It pooled…
This study set out to see whether exercise training raises resting testosterone in men who were not very active but otherwise healthy. It pooled 11 randomized trials covering 421 men…
This meta-analysis set out to clarify how sleep deprivation affects testosterone levels in healthy men. It pooled data from 18 studies involving 252 men, comparing testosterone levels after partial sleep…
This study set out to see what happens to a man's testosterone when he cuts fat out of his diet, at a time when levels have been falling across Western…
This meta-analysis set out to see whether physical exercise causes a short-term rise in testosterone levels in men. It pooled data from 48 studies that measured total and free testosterone…
This study set out to see how losing weight affects testosterone in men with obesity. It pooled 24 trials comparing low-calorie diets against bariatric surgery, measuring changes in total testosterone…