The Truth Behind Sauna’s “16-Fold” Growth Hormone Boost
A closer look at the real protocol behind sauna’s viral growth hormone study
Jul 12, 2026 12:26 PM EDT
Context is important when discussing the benefits of a specific intervention for health and fitness. In an era of headline reading, it’s good to get in the habit of asking more questions. Even research studies can be misinterpreted if you don’t look at the big picture
For example, sauna use is often touted for its effects on growth hormone. What is often cited is a study from the 1980s which showed a 16-fold increase in growth hormone from using the sauna. A 16-fold increase is massive
Increases in growth hormone can aid in tissue repair, fat loss, muscle protein synthesis , and collagen synthesis. So you can see why this would be eye-opening for people looking to improve their health
But again, what is the context? The 16-fold increase was after two one-hour sauna sessions per day for a week straight. Two hours in the sauna every day is a lot to ask of someone. In addition, the elevation in growth hormone was acute, or temporary
Another study by Kukkonen-Harjula et al. had a more reasonable protocol of two 15-20 minute sessions with varying temperatures. This saw a two-to-five-fold increase depending on how hot it was. This study showed that the growth hormone response depends on the intensity of the heat exposure
This is not to say to stop using the sauna, or that sauna use doesn’t work; it clearly does. It’s more of a cautionary tale to temper your expectations. Think of the sauna as an additional “pulse” of growth hormone output, similar to the one you get when sleeping. This is certainly beneficial, just not something that’s going to get you jacked or heal an injury overnight
The bigger lesson here isn’t about growth hormone, or even about saunas. It’s about how easy it is for a real finding to get flattened into a headline, and how a headline can turn a “16-fold increase” into an unspoken promise. The study wasn’t wrong, and neither is the excitement around sauna use. What’s missing is the protocol behind the number
