Sauna Benefits: What the research Actually Shows (2026)

What does a sauna claim to do?

Sauna fans and sellers say regular sessions:

• protect your heart and help you live longer
• lower blood pressure
• reduce the risk of dementia and stroke
• ease muscle and joint pain and help recovery
• improve sleep and lower stress
• "detox" the body through sweat
• burn fat or help weight loss

Some of these have reasonable support. Others rest on a misunderstanding of how the body works. Here is how each claim stacks up.

What does the evidence show?

Does sauna use really help your heart?

The headline study is from the Kuopio Ischaemic Heart Disease (KIHD) cohort in eastern Finland. Laukkanen and colleagues followed 2,315 middle-aged men for about 21 years. Compared with men who used a sauna once a week, those who went four to seven times a week had a 63% lower risk of sudden cardiac death (hazard ratio 0.37) and lower all-cause mortality, after adjusting for standard heart risk factors. Sessions longer than 19 minutes were linked to lower risk than sessions under 11 minutes.

The same cohort later linked frequent sauna use with a lower chance of developing high blood pressure and dementia, and a separate Finnish cohort that included women linked it with lower stroke risk. A 2018 Mayo Clinic Proceedings review pulls this together and suggests plausible mechanisms: better blood vessel function, less arterial stiffness and lower blood pressure.

The limits matter. These are observational studies (they watch what people do rather than assign them to a sauna), mostly in Finnish men, where saunas are part of normal life. Men who can sauna four to seven times a week may be healthier, wealthier or less stressed in ways the adjustments miss. Much of the research comes from one research group. So the heart link is consistent and biologically plausible, but not proven to be cause and effect.

What about infrared saunas?

Infrared saunas heat your body more directly at lower air temperatures (typically 45 to 65°C, against 80 to 100°C in a traditional sauna). They have not been studied in long-term cohorts. The best data come from Japanese "Waon" therapy trials in heart failure. A 2018 meta-analysis found that 15 minutes at 60°C, five times a week for two to four weeks, was associated with short-term improvements in heart function markers. Strength of evidence ranged from moderate to insufficient. An older review of far-infrared saunas found limited support for blood pressure and heart failure and fairly strong evidence against claims that they lower cholesterol.

The broadest overview, a 2018 systematic review by Hussain and Cohen, included 40 studies and 3,855 people across sauna types. Only 13 were randomised trials and most had fewer than 40 people. Most reported benefits, but the authors concluded better-quality data are needed.

Traditional vs infrared sauna: which is better?

For evidence, traditional wins: almost all the long-term heart and longevity data come from hot, dry Finnish saunas. Infrared is gentler and easier to tolerate, and has short-term trial data in heart failure patients. Sauna blankets are a third category again: they wrap you in heated layers with your head outside, and we found no trials testing them directly. See our guide to infrared saunas and sauna blankets for what to check before buying one.

Can you sweat out toxins in a sauna?

This is the weakest claim. Sweat is mostly water and salt. Your liver and kidneys do the work of clearing waste and foreign substances. When researchers estimated how much of the long-lasting pollutants (persistent organic pollutants, or POPs) people could lose through sweat, Imbeault and colleagues concluded the amount is negligible compared with what we take in each day. Heavy sweating also removes water and salt you then need to replace. Sauna weight loss is water, which returns when you drink.

Who might reasonably try a sauna?

Healthy adults who enjoy it and want a relaxing habit that may support heart health. The Finnish data suggest benefits are linked to regular use (several times a week) of 15 to 20 minutes, which is a habit, not a one-off. If you already exercise, a sauna may be a pleasant addition, not a replacement.

Who should be careful?

• Pregnant women. NHS guidance says there is little research and you may choose to avoid saunas, hot tubs and steam rooms because of the risks of overheating, dehydration and fainting. It notes a significant rise in core body temperature could be harmful, particularly in the first 12 weeks.
• Anyone who has been drinking. In a study of 77 sauna deaths in Sweden, 71% of those tested had alcohol in their blood, 44% of deaths were alcohol-related and nearly all were found alone. Do not drink before or during a sauna, and do not sauna alone if you can avoid it.
• People with heart conditions, such as unstable angina, a recent heart attack, severe aortic stenosis or very low blood pressure, should talk to their GP or cardiologist first. Heat raises heart rate and shifts blood to the skin.
• People prone to fainting or taking medicines that lower blood pressure or affect sweating.
• Men trying for a baby. One small study in the Hussain and Cohen review found sauna use disrupted sperm production, which reversed after stopping.
• Children and older adults need shorter, cooler sessions and supervision.

If you want to try it: what to look for

• Public or gym saunas first. This is the cheapest way to see whether the habit sticks.
• Traditional vs infrared at home. A traditional sauna matches the research best but usually needs garden space and a hardwired heater. Infrared cabins plug in indoors.
• Materials. Solid untreated or thermally modified wood and FSC certification are better signs than glued composites with no data. Ask about glues and finishes.
• Electrics. Look for UKCA or CE marking (self-declared by the maker), a clear wattage and installation by a qualified electrician for anything over a 13A plug.
• EMF claims. Ask for measured figures, units and distances. See our sauna blanket guide for what the numbers mean.

Two examples from our home sauna guide: the Finnmark Micro Thermowood Barrel Sauna for traditional heat, and the Clearlight Sanctuary 1 Person Infrared Sauna, which publishes its EMF readings.

Bottom line

Regular traditional sauna use is one of the better-supported wellness habits, with consistent links to heart health in long-term Finnish studies, though not proof it is the sauna doing the work. Infrared has promising short-term data in heart failure. "Detox" and fat-loss claims are not supported. Skip the sauna if you are pregnant or have been drinking, and check with a doctor if you have a heart condition.