Does sauna increase human growth hormone?

Yes. Sauna exposure can temporarily raise human growth hormone (GH) levels.

• 1. First day: In one study, GH increased about 16-fold on day one; with repeated exposure, the rise was smaller—about 3–4-fold on day three. 1
• 2. Example protocol: One study used 20 minutes in the sauna, 30 minutes cooling, then another 20-minute sauna session. Repeated sessions across days produced larger increases than the first session alone, though the response diminished with repeated exposure. 2
• 3. Safety: Heat exposure can be dangerous; excessive overheating can cause severe harm or death. Be cautious and avoid pushing heat beyond what is safe. 3