The claim
“A sauna session raises your growth hormone 16-fold.”
Stretched. The 16-fold rise came from ten men doing two hour-long saunas a day for a week, and it faded after the third day. One ordinary session gives a small, brief bump in younger men and none in older men.
Updated Sep 24, 2026 · 1 study reviewed
The claim pulls a real finding well past what the study showed.
People say it in places like these
Huberman Lab podcast
With the right sauna protocol, anybody can raise their growth hormone 16-fold.
See an example ↗Rhonda Patrick's FoundMyFitness
Seventeen men and women saw their growth hormone rise 16-fold by the third day.
See an example ↗Infrared sauna sellers
Using an infrared sauna raises growth hormone and lowers cortisol.
The research found this
Finnish researchers published the number in 1986. Ten healthy men spent an hour in an 80°C sauna twice a day for seven days, and their growth hormone rose 16-fold against their own starting levels.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗ There was no control group. The authors reported that the rise faded after the third day and suggested that dehydration might drive it.
One normal 15-minute round at 72°C took growth hormone from 2 to 5 µg/L in six men aged 31 to 46. In six men aged 49 to 66 it didn't rise at all.Source 2 · Clinical trialHeat Exposure Elevates Plasma Immunoreactive Growth Hormone-Releasing Hormone Levels in Man*Leppäluoto J, Tapanainen P, Knip M. The Journal of Clinical Endocrinology & Metabolism, 1987.Read the paper ↗PubMed ↗ Another experiment found no growth hormone response to a second 30-minute sauna taken 80 to 150 minutes after the first.Source 3 · Randomized trialGrowth hormone response to different consecutive stress stimuli in healthy men: Is there any difference?Jezova D, Radikova Z, Vigas M. Stress, 2007.Read the paper ↗PubMed ↗
A Finnish review of sauna and hormones reports that the changes during heat stress return to normal within a couple of hours.Source 4 · ReviewHow the sauna affects the endocrine systemKukkonen-Harjula K, Kauppinen K. Annals of clinical research, 1988.Read the paper ↗PubMed ↗
The dial reads 60°H for four reasons
How the reading adds up
12 + 16 + 16 + 16 = 60°H
EvidenceWhat kind of human evidence exists?
12/25A 1986 study of ten men with no control group produced the figure, and the number it reports is a marker in the blood.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗
ConsistencyHave other studies found the same thing?
16/25One 15-minute sauna took growth hormone from 2 to 5 µg/L in men aged 31 to 46. It did nothing measurable in men aged 49 to 66, and a second sauna later the same day produced no rise at all.Source 2 · Clinical trialHeat Exposure Elevates Plasma Immunoreactive Growth Hormone-Releasing Hormone Levels in Man*Leppäluoto J, Tapanainen P, Knip M. The Journal of Clinical Endocrinology & Metabolism, 1987.Read the paper ↗PubMed ↗Source 3 · Randomized trialGrowth hormone response to different consecutive stress stimuli in healthy men: Is there any difference?Jezova D, Radikova Z, Vigas M. Stress, 2007.Read the paper ↗PubMed ↗
MagnitudeDoes the claim match the size of the effect?
16/25People quote the 16-fold number as if it came from a normal session. In the studies, one normal session gave younger men about a two-and-a-half-fold rise that faded within hours, and older men got no rise at all.Source 2 · Clinical trialHeat Exposure Elevates Plasma Immunoreactive Growth Hormone-Releasing Hormone Levels in Man*Leppäluoto J, Tapanainen P, Knip M. The Journal of Clinical Endocrinology & Metabolism, 1987.Read the paper ↗PubMed ↗Source 4 · ReviewHow the sauna affects the endocrine systemKukkonen-Harjula K, Kauppinen K. Annals of clinical research, 1988.Read the paper ↗PubMed ↗
DoseDoes the studied dose match how people use it?
16/25The men spent an hour at 80°C twice a day for seven days, so they logged fourteen hours of sauna in a week. The authors suggested the dehydration from all that sweating may drive the hormone release.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗
The claim drifts from the data here
The 16-fold figure gets repeated without its protocol. Fourteen hours of sauna in a week is far from the two or three sessions of 5 to 20 minutes that a Finnish review describes as typical, and the response faded after the third day.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗Source 5 · ReviewCardiovascular and Other Health Benefits of Sauna Bathing: A Review of the EvidenceLaukkanen JA, Laukkanen T, Kunutsor SK. Mayo Clinic Proceedings, 2018.Read the paper ↗PubMed ↗
People link the number to building muscle and slowing aging, and researchers haven't followed sauna users to see whether either happens.
Put it to use
Treat the growth hormone bump as a lab curiosity. If you use a sauna, build your routine around its heart and circulation effects, since the evidence there runs much deeper.
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People also ask
How much does one sauna session raise growth hormone?
Not much. In one small study, a 15-minute round at 72°C took growth hormone from 2 to 5 µg/L in men aged 31 to 46. Men aged 49 to 66 had no significant rise.Source 2 · Clinical trialHeat Exposure Elevates Plasma Immunoreactive Growth Hormone-Releasing Hormone Levels in Man*Leppäluoto J, Tapanainen P, Knip M. The Journal of Clinical Endocrinology & Metabolism, 1987.Read the paper ↗PubMed ↗
Where does the 16-fold growth hormone figure come from?
It comes from a 1986 Finnish study in which ten men spent an hour at 80°C twice a day for a week. The response faded after the third day, and the study had no control group.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗
Check these claims next
65°H
Stretched
“Sauna helps you build and keep muscle.”
Heating one muscle for hours a day slowed its loss in immobilized legs and gave small strength gains in some trials. The one sauna trial that measured muscle growth found no extra gain from post-workout infrared sessions.
74°H
Stretched
“Sauna switches on heat shock proteins that slow aging.”
In one sauna study, blood levels of heat shock protein 72 rose 48.7% on average after 30 minutes at 73°C. A review of 51 controlled heating studies found no change overall, and the idea that these proteins slow aging comes from animal research.
68°H
Stretched
“Sauna boosts testosterone.”
Most sauna studies, including a week of two hour-long sessions a day and three months of regular use, found no change in testosterone. Two studies found short rises right after the heat, and one of those came only when men stayed in until they were exhausted.
We cited these sources
- 01Leppäluoto J, Huttunen P, Hirvonen J, Väänänen A, Tuominen M, Vuori J. Endocrine effects of repeated sauna bathing. Acta Physiologica Scandinavica. 1986;128(3):467-470. doi:10.1111/j.1748-1716.1986.tb08000.x PMID 3788622
- 02Leppäluoto J, Tapanainen P, Knip M. Heat Exposure Elevates Plasma Immunoreactive Growth Hormone-Releasing Hormone Levels in Man*. The Journal of Clinical Endocrinology & Metabolism. 1987;65(5):1035-1038. doi:10.1210/jcem-65-5-1035 PMID 3117831
- 03Jezova D, Radikova Z, Vigas M. Growth hormone response to different consecutive stress stimuli in healthy men: Is there any difference?. Stress. 2007;10(2):205-211. doi:10.1080/10253890701292168 PMID 17514589
- 04Kukkonen-Harjula K, Kauppinen K. How the sauna affects the endocrine system. Annals of clinical research. 1988;20(4):262-266. PMID 3218898
- 05Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence. Mayo Clinic Proceedings. 2018;93(8):1111-1121. doi:10.1016/j.mayocp.2018.04.008 PMID 30077204