Sauna for polycystic ovary syndrome
Evidence review
Overview
One controlled study assigned 18 women with obesity (mean BMI 41) and polycystic ovary syndrome to 30 one-hour hot-tub sessions over 8-10 weeks or to a time control. The heat group showed lower fasting glucose, glucose and insulin responses to an oral glucose tolerance test, serum testosterone, muscle sympathetic nerve activity, blood pressure, C-reactive protein and total cholesterol, with no change in BMI; the control group did not change. A Russian open-label randomized trial of 120 women with PCOS and grade 1 obesity found larger falls in BMI, atherogenic index and insulin-resistance index and in anxiety when a 24-day course of contrast (hot-cold) baths and underwater shower-massage was added to diet. The hot-tub findings come from a single small non-randomized study, and the randomized trial combined several water treatments, so neither isolates the effect of heat.
Key findings
- Fasting glucose 105 to 89 mg/dL (P=0.001), insulin AUC 126,924 to 91,233 (P=0.012), serum testosterone 51 to 34 ng/dL (P=0.033) after 30 hot-tub sessions; no change in controls (Ely 2019, Am J Physiol Endocrinol Metab).
- Same participants: systolic BP 124 to 114 mmHg and diastolic BP 77 to 68 mmHg (both P<0.001), muscle sympathetic burst frequency 20 to 13 bursts/min (P=0.012), total cholesterol 5.4 to 5.0 mmol/L (P=0.028) (Ely 2019, Am J Physiol Regul Integr Comp Physiol).
- BMI did not change in either group.
- Open-label RCT, 120 women with PCOS and obesity: diet plus contrast baths and underwater shower-massage for 24 days vs diet alone, BMI -11.3% vs -4.9%, insulin-resistance index 2.9 to 2.0 (p<0.05 vs control), normal LH/FSH ratio in 33.3% vs 6.6% (Chekhoeva 2024).
Every study we reviewed
3 found benefit
Each study was checked on PubMed. The colored edge shows the direction of the result.
Heat therapy improves glucose tolerance and adipose tissue insulin signaling in polycystic ovary syndrome.
Ely BR et al. Am J Physiol Endocrinol Metab. 2019. PubMed 31136202 · DOI · Free full text
- Who
- Women with obesity and PCOS (age 27, BMI 41.3), age- and BMI-matched
- What
- Hot-tub immersion, 30 one-hour sessions over 8-10 weeks (n=9) vs time control (n=9)
- Protocol
- 60 min · 3-4/wk · 8-10
- Measured
- Oral glucose tolerance, adipose tissue insulin signaling, testosterone
- Result
- Fasting glucose 105 to 89 mg/dL (P=0.001); glucose AUC 18,698 to 16,987 mg/dL x min (P=0.028); insulin AUC 126,924 to 91,233 (P=0.012); adipocyte p-AKT 0.29 to 0.93 AU (P=0.021); testosterone 51 to 34 ng/dL (P=0.033); no change in controls; BMI unchanged.
- Limitations
- Non-randomized assignment; very small; single center; short follow-up.
Heat therapy reduces sympathetic activity and improves cardiovascular risk profile in women who are obese with polycystic ovary syndrome.
Ely BR et al. Am J Physiol Regul Integr Comp Physiol. 2019. PubMed 31483156 · DOI · Free full text
- Who
- Women with obesity and PCOS (age 27, BMI 41.3); same participants as the metabolic report
- What
- Hot-tub immersion, 30 one-hour sessions over 8-10 weeks (n=9) vs time control (n=9)
- Protocol
- 60 min · 3-4/wk · 8-10
- Measured
- Muscle sympathetic nerve activity, blood pressure, CRP, cholesterol, arterial wall thickness, FMD after ischemia-reperfusion
- Result
- MSNA 20 to 13 bursts/min (P=0.012); SBP 124 to 114 mmHg and DBP 77 to 68 mmHg (P<0.001); CRP 19.4 to 15.2 nmol/L (P=0.018); total cholesterol 5.4 to 5.0 mmol/L (P=0.028); carotid wall thickness 0.054 to 0.044 cm (P=0.010); FMD after ischemia-reperfusion 5.6% to 9.5% (P<0.001); no change in controls.
- Limitations
- Same small non-randomized cohort; surrogate outcomes.
Hydrotherapy Application for Women with Polycystic Ovary Syndrome: a Randomized Study
Chekhoeva AN et al. Bulletin of Rehabilitation Medicine. 2024. Not in PubMed: source · DOIRussian publication; title and summary translated by SaunaLMN. Original title: Применение гидротерапии у женщин с синдромом поликистозных яичников: рандомизированное исследование
- Who
- Women aged 20-45 with PCOS, grade 1 obesity (median BMI 32.6) and menstrual disorders (North Ossetia, Russia)
- What
- Low-carbohydrate diet plus a 24-day hydrotherapy course (n=60): 12 freshwater contrast baths (warm water rising to 104 F (40 C) for 3 min alternating with cold water falling to 62.6 F (17 C) for 1 min, 3-4 cycles) on alternate days with 12 underwater shower-massages at 96.8-100.4 F (36-38 C) for 30 min; vs diet alone (n=60)
- Protocol
- 104 °F · 7/wk · 3.5
- Measured
- BMI, atherogenic index, insulin-resistance index, anxiety (Spielberger-Khanin), mood, LH/FSH ratio
- Result
- BMI fell 11.3% (32.7 to 29.0) with hydrotherapy vs 4.9% (32.4 to 30.8) with diet alone; atherogenic index 3.6 to 2.3 and insulin-resistance index 2.9 to 2.0 with hydrotherapy (p<0.05 vs control) with no significant change on diet alone; state anxiety 51.9 to 38.7 vs 52.8 to 46.7; normal LH/FSH ratio restored in 33.3% vs 6.6%.
- Limitations
- Open label, no sham; the intervention combined contrast (hot-cold) baths with underwater massage, so heat is not isolated; medians reported; ovulation outcomes not reported by group.
Protocols used in the studies
Hot-tub immersion for 1 hour per session, 30 sessions over 8-10 weeks (about 3-4 per week); water temperature was not reported in the abstracts. The Russian RCT used contrast baths (warm water rising to 104 F (40 C) for 3 minutes, cold water falling to 62.6 F (17 C) for 1 minute, 3-4 cycles) on alternate days with 30-minute underwater shower-massage at 96.8-100.4 F, for 24 days.
What is still unknown
Whether the findings replicate in a randomized trial; effects on ovulation, menstrual regularity and fertility; effects of dry sauna rather than hot-tub immersion; women with PCOS who are not obese; durability after sessions stop. Whether heat alone, rather than combined hydrotherapy with diet, affects metabolic, hormonal or ovulatory outcomes in PCOS.
Safety
Cautions for sauna in this condition
- No adverse events were reported in the abstracts (PMID 31136202, 31483156).
- Many patients with PCOS are trying to conceive: maternal hyperthermia in early pregnancy is associated with neural tube defects (OR 1.92, 95% CI 1.61-2.29; PMID 15703536). Avoiding core-temperature elevation when pregnancy is possible is a reasonable precaution.
- See the sauna general safety entry for cardiovascular contraindications.
For clinicians
Suggested rationale
In a small controlled study of women with obesity and PCOS, 30 one-hour hot-tub sessions over 8-10 weeks were followed by lower fasting glucose, insulin response, testosterone and blood pressure without weight change (Ely 2019), and an open-label RCT found greater metabolic and weight improvements when contrast baths and underwater massage were added to diet (Chekhoeva 2024); the evidence is preliminary, and no randomized trial has tested heat alone.
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