Short answer: Sauna use — including infrared — can significantly increase human growth hormone (HGH) levels, with studies showing a 2–5x spike after a single session. This is one of the most compelling biological mechanisms behind sauna's recovery and anti-aging effects.
Why Growth Hormone Matters
Human growth hormone (HGH) is produced by the pituitary gland and drives:
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Muscle repair and growth — stimulates protein synthesis in muscle tissue
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Fat metabolism — promotes lipolysis (fat breakdown), especially visceral fat
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Recovery speed — accelerates tissue repair after training
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Sleep quality — most HGH is released during deep sleep; sauna may amplify this
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Longevity — linked to cellular repair, collagen production, skin integrity
HGH naturally declines ~14% per decade after age 30. Strategies that boost it — without pharmaceuticals — are genuinely valuable.
The Research on Sauna and HGH
Key Studies
Leppäluoto et al. (1986): Two 20-minute sauna sessions at 80°C with a 30-minute break produced a 2-fold increase in plasma growth hormone levels. No cool-down between sessions dampened the effect.
Kukkonen-Harjula et al. (1989): A single 20-minute sauna session at high heat led to significant GH spikes — and the response was amplified with repeated sessions over multiple weeks.
Rhonda Patrick, PhD (2019 — foundational review): Summarized that sauna use creates a hormetic heat stress response. Core temperature elevation triggers thermosensors in the hypothalamus, which stimulate GH-releasing hormone (GHRH), which then prompts the pituitary to release GH.
Infrared Specifically
Most foundational GH research uses traditional (Finnish) saunas at 80–100°C. Infrared saunas typically operate at 45–65°C — lower ambient temperature but deeper tissue penetration. The core temperature elevation is what matters for GH release, not the air temperature.
Evidence suggests infrared saunas produce similar — if not equal — core temperature increases with more comfort and longer sustainable session times, which may produce comparable hormonal responses.
How Sauna Triggers HGH: The Mechanism
- Heat stress raises core body temperature
- Hypothalamus detects the rise and releases GHRH (growth hormone-releasing hormone)
- GHRH signals the pituitary gland to secrete HGH into the bloodstream
- Simultaneously, somatostatin (HGH inhibitor) is suppressed
- Net result: significant spike in circulating GH
The body treats heat stress similarly to exercise stress — both are hormetic stressors that trigger adaptive responses.
Optimizing Your Sauna Protocol for HGH
Timing relative to exercise
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Post-workout sauna: Most effective. Combines training-induced GH release with heat-induced GH release — potential additive effect.
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Fasted sauna (morning): GH is naturally highest in the morning after an overnight fast. A fasted sauna session may amplify this baseline pulse.
Session structure
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Duration: 20–30 minutes per session
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Temperature: 55–65°C for infrared (target a core temp rise of ~1–2°C)
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Multiple sessions: Two sessions with a 20–30 minute cooling break may amplify GH response more than one continuous session
What blunts HGH release
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Eating beforehand: Insulin suppresses GH. Avoid carbohydrates or large meals 2+ hours before sauna if HGH optimization is a goal.
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Alcohol: Dramatically suppresses GH release — avoid post-sauna drinking
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Poor sleep: GH release is closely tied to slow-wave sleep; chronic sleep deprivation blunts the sauna benefit
HGH vs. Cortisol: The Balance
Heat stress also transiently elevates cortisol (the stress hormone). This is normal and short-lived — cortisol returns to baseline within 1–2 hours post-sauna in healthy individuals.
For optimal hormonal outcomes:
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Keep sessions under 35 minutes to avoid prolonged cortisol elevation
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Prioritize rest and rehydration post-session
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Don't sauna daily if recovering from heavy training — 3–5x/week is sufficient
Practical Stack for Biohackers
| Protocol | Details |
|---|---|
| Post-strength training | Sauna 20–30 min within 30 min of finishing workout |
| Fasted morning | Sauna 20 min before breakfast |
| Pre-sleep | Sauna 2–3 hours before bed (raises then drops core temp, deepens sleep, amplifies overnight GH pulse) |
| Cold + heat contrast | Sauna → cold plunge → sauna. The hormetic combo may amplify total HGH response. |
Frequently Asked Questions
How much does sauna raise growth hormone? Studies show 2–5x baseline increases after a single session. Elite protocols (multiple sessions, heat cycling) may produce even greater spikes.
Does infrared sauna increase HGH as well as traditional sauna? Evidence is promising. The key driver is core temperature elevation, which infrared achieves effectively — often with greater comfort and longer sustainable sessions.
How often should I use sauna for HGH benefits? 3–5 sessions per week appears optimal based on current research. Daily use is safe for most people but may offer diminishing GH returns without adequate recovery.
Is sauna better than supplements for HGH? For natural, non-pharmacological HGH elevation, regular sauna use competes favorably with most OTC supplements (arginine, GABA, etc.), which have limited evidence. The effect is real, measurable, and drug-free.
Can women benefit from sauna-induced HGH? Yes. Women naturally have higher baseline GH pulsatility than men. Sauna-induced GH spikes are documented across both sexes.
Bottom Line
Infrared sauna is one of the few lifestyle tools with direct, measurable evidence for increasing growth hormone. The mechanism is well-understood, the protocol is simple, and the effect is real.
Combine post-workout sauna sessions with quality sleep and fasted timing for maximum HGH benefit — no injections required.
Sources: Leppäluoto et al. (1986), Kukkonen-Harjula et al. (1989), Rhonda Patrick PhD (2019 foundational review), Journal of Clinical Endocrinology & Metabolism