Can Sauna Heat Therapy Ease Fibromyalgia Pain? A Randomized Sham-Controlled Trial Says Yes

Fibromyalgia causes widespread chronic pain that's notoriously difficult to treat, which makes any well-designed trial on a non-drug intervention worth a close look. A 2023 randomized, sham-controlled trial tested whole-body infrared heat therapy (a sauna-like whole-body hyperthermia) specifically in people with medically confirmed fibromyalgia.

What the research looked at

41 adults with fibromyalgia syndrome were randomized to either six sessions of mild water-filtered infrared-A whole-body hyperthermia (heated to about 38.7°C for roughly 15 minutes) or a sham treatment, over three weeks. Pain was measured on a standard 0–10 scale at multiple points, including a 30-week follow-up.

What they found

By week four, the heat-therapy group had a 30.7% reduction in pain versus a 9.5% reduction in the sham group (p=0.015) — nearly half the active-treatment group (10 of 21) reached a clinically meaningful 30%+ pain reduction, compared to 4 of 20 in the sham group. The benefit wasn't just short-lived: at the 30-week follow-up, pain was still down 17.0% from baseline (p=0.002).

What this means in practice

This is a genuinely strong result for a chronic pain condition with few reliable treatment options — randomized, sham-controlled, with effects still measurable seven months later. If you have fibromyalgia and are considering heat therapy, this is worth discussing with your doctor, especially around session frequency and temperature, since the trial used a specific, monitored protocol rather than casual sauna use.