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 by day three. One ordinary session gives a small, brief bump in younger men and none in older men.
Updated Sep 24, 2026 · 1 study reviewed
A real finding has been pulled 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
The number traces to a 1986 Finnish study. 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 ↗ The study had no control group. The authors reported that the rise faded after the third day, and they suggested dehydration might be what drives it.
A normal session moves the number much less. After one 15-minute round at 72°C, growth hormone went from 2 to 5 µg/L in six men aged 31 to 46 and did not rise at all in six men aged 49 to 66.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 ↗ In another experiment, a second 30-minute sauna taken 80 to 150 minutes after the first produced no growth hormone response.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 evidence exists in people?
12/25The figure comes from a 1986 study of ten men with no control group. Growth hormone is a blood marker, and no study has tied a sauna-driven rise to muscle or aging.Source 1 · Clinical trialEndocrine effects of repeated sauna bathingLeppäluoto J, Huttunen P, Hirvonen J, et al.. Acta Physiologica Scandinavica, 1986.Read the paper ↗PubMed ↗
ConsistencyHas the finding held up?
16/25One 15-minute sauna took growth hormone from 2 to 5 µg/L in men aged 31 to 46 and did nothing measurable in men aged 49 to 66. 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?
16/25The popular version attaches the 16-fold number to a normal session. A normal session gave younger men about a two-and-a-half-fold rise that faded within hours, and older men 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 protocol match how people use it?
16/25The protocol was an hour at 80°C twice a day for seven days, fourteen hours 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 leaves its protocol behind. 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 had already faded by day three.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 ↗
No study has followed sauna users to see whether the extra growth hormone builds muscle or slows aging, so the benefit people attach to the number has never been measured.
Put it to use
Treat the growth hormone bump as a lab curiosity. If you use a sauna, choose your routine for its heart and circulation effects, where the evidence runs much deeper.
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People also ask
How much does one sauna session raise growth hormone?
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 and produced no significant rise in men aged 49 to 66.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?
A 1986 Finnish study of ten men who 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.”
One sauna study found blood heat shock protein 72 up 48.7% on average after 30 minutes at 73°C, and a review of 51 controlled heating studies found no change overall. No study in people has tied heat shock proteins from a sauna to slower aging.
68°H
Stretched
“Sauna boosts testosterone.”
In most sauna studies testosterone did not change, and the null results include a week of two hour-long sessions a day and three months of regular use. Two studies found short rises right after the heat, and one of those rises came only when men were pushed to exhaustion.
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