Sauna sellers promise a lot: a stronger heart, better skin, weight loss, fewer colds. Some of that has research behind it. Some of it doesn’t.
This page sorts the claims by how much evidence sits under each one, using a medical review, one large long-term study, and two hospital sources. It is general information, not medical advice. If you are choosing a cabin, the home sauna buying guide covers that side.
Short answer: the best-supported link is between regular sauna use and heart health, and it comes from observational studies of Finnish men. Sore muscles and stress have some support. Weight loss, skin, and immunity claims have little. Ask a doctor first if you are pregnant or have a heart or blood pressure condition.
What happens to your body in a sauna
Harvard Health describes the basics. In dry heat that “can get as high as 185° F,” your pulse rate “jumps by 30% or more,” and the heart nearly doubles the blood it pumps each minute. It adds that “the average person will pour out a pint of sweat during a short stint in a sauna.”
UCLA Health puts the heart rate at 100 to 150 beats per minute and says the heat causes blood vessels to open.
So a sauna session is a load on the circulation. That is the root of both the possible benefits and the cautions.
Claims and the evidence behind them
| Claim | What the sources say | How strong |
|---|---|---|
| Heart health | Frequent sauna use was associated with lower risk of fatal heart events in a 20-year study of 2,315 Finnish men (JAMA Internal Medicine, 2015) | Observational: a link, not proof |
| Blood pressure | UCLA Health reports an immediate positive effect; Harvard Health calls the response “unpredictable, rising in some people but falling in others” | Mixed |
| Sore muscles | “Sore muscles often respond to heat” (Dr. Amy Zack, Cleveland Clinic) | Some support |
| Stress | Cleveland Clinic cites evidence for people in high-stress situations | Some support |
| Skin | “Little to no research, only clinical anecdotal support” (Dr. Zack) | Weak |
| Colds and immunity | “Further research is needed” (Dr. Zack) | Weak |
| Weight loss | The loss is water. “That is not weight loss, that is dehydration” (Dr. Zack) | Not supported |
The heart study, in plain numbers
The most-quoted sauna study followed 2,315 men aged 42 to 60 in eastern Finland for a median of 20.7 years.
Compared with men who used a sauna once a week, those who went 4 to 7 times a week had a hazard ratio of 0.37 for sudden cardiac death and 0.60 for death from any cause. Men who went 2 to 3 times a week landed in between, at 0.78 and 0.76.
The authors’ conclusion: “Increased frequency of sauna bathing is associated with a reduced risk” of these outcomes.
Here’s what the headline won’t tell you. The study was observational, it included only middle-aged Finnish men, and the saunas were traditional Finnish ones. It can’t show that the sauna caused the difference, and it says nothing direct about women or infrared cabins.
What the review adds
A 2018 review in Mayo Clinic Proceedings pulled together the studies available to that date. It says sauna bathing “may be linked to several health benefits,” including lower risk of high blood pressure and cardiovascular disease, and relief in conditions such as arthritis, headache, and flu.
The wording matters. “May be linked” is the review’s own phrase, and it lists “areas of outstanding uncertainty” as part of its scope.
Does the type of sauna matter?
Most of the research above is on traditional Finnish saunas, which run hotter than infrared cabins. The catalog shows the gap.
| Model | Type | Stated maximum |
|---|---|---|
| Finnmark FD-4 Trinity | Hybrid | 190°F traditional stove, 170°F infrared |
| Sunlighten Solo Dome | Portable infrared | 150°F |
| Dynamic Andora | Infrared cabin | 140°F |
My rule of thumb: don’t assume a study of 80 to 100°C Finnish saunas transfers to a 140°F infrared cabin. It might. The sources here don’t test it.
How to use one safely
The hospital sources agree on the basics.
- Keep sessions to about 15 to 20 minutes. New users can start at 5 to 10.
- Drink water before and after.
- Skip the sauna if you have been drinking alcohol.
- Leave if you feel dizzy or unwell.
Who should ask a doctor first
Cleveland Clinic says to avoid the sauna after a recent heart attack or stroke. It says to check with a provider first if you are pregnant, trying to get pregnant, or have a heart condition, including heart failure or high or low blood pressure. UCLA Health adds that sauna use can lower blood pressure, so people with low blood pressure should talk to their physician first.
Bottom line: regular sauna use is associated with better heart outcomes in the best study available, and it helps some people with sore muscles and stress. It is not a weight-loss tool, and it is not for everyone. Check with your doctor if any of the cautions above apply to you.
Sources
- Laukkanen T, Khan H, Zaccardi F, Laukkanen JA, “Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events,” JAMA Internal Medicine, 2015;175(4):542-548: jamanetwork.com
- Laukkanen JA, Laukkanen T, Kunutsor SK, “Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence,” Mayo Clinic Proceedings, August 2018 (abstract): mayoclinicproceedings.org
- Cleveland Clinic, “Get Your Sweat On: The Benefits of a Sauna,” August 12, 2024: health.clevelandclinic.org
- Harvard Health Publishing, “Sauna Health Benefits: Are saunas healthy or harmful?” May 14, 2020 (opening section; the rest is behind a paywall): health.harvard.edu
- UCLA Health, “Benefits of sauna bathing for heart health,” February 1, 2023: uclahealth.org
- Finnmark, Sunlighten, and Dynamic Saunas product listings (maximum temperatures), checked September and October 2026