Published in Human Reproduction, this study examined ten healthy men who used a Finnish sauna twice per week for three months at 80–90°C, with each session lasting 15 minutes. Ten healthy men were exposed to dry heat in a Finnish sauna at 80°C (176°F) for one hour, twice daily, over seven days. This decline is a normal part of aging, but lifestyle factors like chronic stress, poor sleep, excess body fat, sedentary behavior, and excessive alcohol consumption can accelerate it. It shows up in podcast clips, social media posts, and marketing copy from sauna companies trying to sell you on the idea that a few sessions per week will supercharge your hormones.
While cortisol levels usually spike during sauna use, afterward, these levels drop by around 25%. Infrared saunas, specifically, are the best type for these benefits because of the way they work. Use the sauna 2-3x per week for 20 minutes to improve mood levels that increase libido. Saunas do not directly boost testosterone; however, they indirectly reduce cortisol and insulin levels which have been scientifically shown to reduce testosterone.
For men who lift weights or engage in HIIT workouts, saunas accelerate recovery by easing muscle soreness and flushing metabolic waste. Sauna sessions increase heart rate and calorie expenditure, supporting weight management when combined with exercise and diet. The heat-induced relaxation promotes better sleep, sharper focus, and reduced anxiety. Yes, sauna use enhances mental clarity by reducing cortisol and stimulating endorphins. Consistent sauna practice is not just about short-term hormone boosts.
Serum cortisol and plasma ACTH decreased and urinary catecholamine increased slightly at the end of the experiment (P less than 0.05). Consistent use to reduce baseline cortisol (which suppresses testosterone). For many men, the GH response is the more significant hormonal benefit of sauna use. No — it's an acute hormonal response that returns to baseline within hours, similar to the testosterone spike after a hard workout. If you've been having difficulty conceiving, scrotal heat exposure is one of many factors worth evaluating.
The planned sauna sessions were relatively long, and the volunteers were asked to visit a sauna regularly (twice a week for 30 min) for 2 months before the study. During repeated sauna exposure, a strong relationship was also noted between body mass loss, body surface area and heart rate response in healthy adult males (Boraczyński et al., 2018). During thermal stress, hormone production is altered to adapt to the demand for energy, and it responds to the amount of body water and body temperature. A positive correlation between body temperature and PRL secretion was reported by Christensen, Jørgensen, Møller, Møller, and Orskov (1985), whereas Lammintausta et al. (1976) observed a significant decrease in sodium excretion from the body during and after heat exposure in the sauna. Podstawski et al. (2013) demonstrated that a visit to the sauna can be a stressful experience for people who are rarely subjected to heat therapy. Yes — the Leppäluoto 1986 study documented a 2-5x ( %) increase in GH from sauna sessions. It's based on real research — Leppäluoto et al. 1986 documented a 2-5x GH increase from sauna sessions.
Some studies suggest a potential increase in testosterone levels following sauna bathing, while others report no significant change. Several studies have investigated the effects of sauna bathing on the endocrine system, with a particular focus on hormones like cortisol, growth hormone, and testosterone. Growth hormone increases substantially during heat stress, and unlike testosterone, the scrotal heat concern doesn't apply (GH is produced in the pituitary gland).
Maintain healthy body composition (excess fat converts testosterone to estrogen via aromatase). For men focused on body composition and aging well, the GH response to sauna may be the more reliable and significant hormonal benefit. The indirect pathways through which sauna supports testosterone may be more significant than any direct heat effect — and they're better supported by evidence. Sperm production takes approximately 74 days — meaning heat-related effects on fertility are temporary but require weeks to fully reverse after stopping exposure. Hot baths, saunas, tight underwear, laptop computers on laps, and prolonged sitting in heated car seats have all been studied as contributors to male subfertility. While some studies show promising results, the jury’s still out on a definitive sauna-testosterone link.