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 study looked at whether low testosterone in middle-aged and older men is tied to worse blood vessel health through effects on mitochondria, the tiny power plants inside cells. Researchers…
This study looked at whether time spent outdoors is linked to testosterone in men. It analyzed 2,205 men in the US National Health and Nutrition Examination Survey, tracking daily outdoor…
This study set out to see whether exposure to bright light is linked to testosterone in men, an area far less studied than diet and exercise. It analyzed data from…
This study set out to explore how obesity and chronic inflammation relate to testosterone levels in men. It analyzed data from over 7,400 adult men in the US, using body…
This study set out to explore whether cannabis use affects hormone levels in young men. It compared blood steroid levels between 47 cannabis users and 47 non-users, measuring 70 different…
This study looked at how depression, testosterone levels, and shift work are linked in men with symptoms of low testosterone. It reviewed medical records and survey data from 766 men…
This study looked at what drives low testosterone in U.S. men, going beyond aging to include habits and life circumstances. It analyzed over 10,000 men aged 18 and up from…
This study looked at how a man's testosterone and SHBG relate to where his body stores fat. SHBG, or sex hormone-binding globulin, is a protein that binds testosterone and sets…
This study asked which workplace exposures matter most for men's reproductive health. It took 80 men working in an automobile parts plant, measured their exposure to magnetic fields, electric fields,…
This study looked at how lifestyle and hormones affect semen quality and sperm DNA health in men. It examined 278 Indian men aged 21 to 50, measuring sperm count, movement,…
This study set out to explore how trace elements in the blood might relate to testosterone levels and symptoms like low energy, mood issues, and sexual health in young men.…
This study looked at how diet relates to sperm quality, comparing the Mediterranean diet, which is built on seasonal, fresh and whole foods, against ultra-processed foods, which are high in…
This study looked at whether eating more omega-3 fatty acids (healthy fats found in fish and some plants) is linked to higher testosterone levels in men. It used data from…
This study looked at whether sleep duration affects markers of male fertility in young men. It analyzed 1,055 Danish men who reported their sleep habits and gave semen and blood…
This study set out to examine how cigarette smoking affects semen quality, hormone levels, metabolic health, zinc levels, and sperm DNA damage in young Russian men. It compared 450 smokers…
This study set out to see whether testosterone in men varies with the season, independently of age, weight and existing illness. It used the medical records of 27,328 Israeli men…
This study set out to find hormonal and biochemical markers that could flag overtraining syndrome (OTS) in male athletes. It compared 14 men with OTS to 25 healthy athletes and…
This study looked at whether vitamin D levels track with testosterone, and with hypogonadism (when the testicles do not make enough testosterone, which shows up as low drive, fatigue and…
This study asked why men differ so much in how warm their testicles run. Scrotal skin temperature was logged every five minutes for 24 hours in 48 men, made up…
This study set out to find which parts of an ordinary day actually move scrotal temperature. A thermistor (a small temperature sensor) was clipped to the underwear of 101 men…