Sauna for myalgic encephalomyelitis / chronic fatigue syndrome
Evidence review
Overview
A Japanese group has reported reduced fatigue, improved mood and performance status after 4 weeks of daily far-infrared sauna (Waon) therapy in small uncontrolled series of inpatients with chronic fatigue syndrome, with no reported adverse effects. A related pilot reported symptom improvement alongside increased regional cerebral blood flow on SPECT. A 2025 German pilot in 9 patients described changes in blood-cell autophagy and mitochondrial markers after one session of medical whole-body hyperthermia but reported no clinical outcomes. There are no controlled trials.
Key findings
- Perceived fatigue significantly decreased after 20 Waon sessions; anxiety, depression and fatigue mood scores and performance status improved; pain and vigor unchanged (Soejima 2015, n=10)
- Symptoms reduced in all 11 patients with increased prefrontal and temporal cerebral blood flow (Munemoto 2017, n=11)
- One whole-body hyperthermia session in 9 patients shifted blood-cell autophagy marker LC3-II toward healthy levels; no clinical outcomes measured (Hochecker 2025)
Every study we reviewed
3 found benefit · 1 mixed results
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 10 studies on chronic fatigue syndrome (me/cfs), across all heat and cold therapies, including case reports and older work not graded here.
Effects of Waon therapy on chronic fatigue syndrome: a pilot study.
Soejima Y et al. Intern Med. 2015. PubMed 25748743 · DOI · Free full text
- Who
- consecutive inpatients with chronic fatigue syndrome
- What
- Waon therapy: far-infrared dry sauna then blanket rest
- Protocol
- 140 °F · 15 (plus 30 min warm rest) min · 5/wk · 4 wk
- Measured
- perceived fatigue (NRS), pain, Profile of Mood States, performance status
- Result
- Perceived fatigue significantly decreased after therapy (not at 2 weeks); negative mood (anxiety, depression, fatigue) and performance status significantly improved; pain and vigor unchanged; no adverse effects. Effect sizes not given in abstract.
- Limitations
- uncontrolled; n=10; inpatient setting; single group
Increase in the Regional Cerebral Blood Flow following Waon Therapy in Patients with Chronic Fatigue Syndrome: A Pilot Study.
Munemoto T et al. Intern Med. 2017. PubMed 28717076 · DOI · Free full text
- Who
- patients with chronic fatigue syndrome (mean age 27)
- What
- Waon therapy
- Measured
- symptoms; regional cerebral blood flow (SPECT)
- Result
- Waon therapy reduced symptoms in all 11 patients; regional CBF increased in prefrontal, orbitofrontal and right temporal regions.
- Limitations
- uncontrolled; small; symptom measures not quantified in abstract; same research group
The effects of repeated thermal therapy for two patients with chronic fatigue syndrome.
Masuda A et al. J Psychosom Res. 2005. PubMed 15992574 · DOI
- Who
- two patients with chronic fatigue syndrome unresponsive to prednisolone
- What
- far-infrared dry sauna plus post-sauna warming, 35 inpatient sessions, then 1-2 outpatient sessions/week for 1 year
- Protocol
- 140 °F · daily, then 1-2/wk
- Measured
- fatigue, pain, sleep disturbance, low-grade fever
- Result
- Symptoms markedly improved after 15-25 sessions; no relapse during the first year after discharge.
- Limitations
- two cases; no control
Heat vs. Fatigue: Hyperthermia as a Possible Treatment Option for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).
Hochecker B et al. Int J Mol Sci. 2025. PubMed 40508148 · DOI · Free full text
- Who
- people with ME/CFS, compared with healthy donors
- What
- single session of whole-body hyperthermia
- Protocol
- single session/wk
- Measured
- peripheral blood mononuclear cell autophagy (LC3-II), mitochondrial function and mRNA expression
- Result
- ME/CFS cells had higher LC3-II and mitochondrial function than healthy donors at baseline; after one WBH session LC3-II fell toward healthy levels and mitochondrial parameters rose. No clinical outcomes reported.
- Limitations
- cellular outcomes only; single session; very small; no control intervention
Protocols used in the studies
Clinical studies used the Waon protocol: 140 F (60 C) far-infrared sauna for 15 minutes, then 30 minutes of rest under a blanket, once daily 5 days per week for 4 weeks (20 sessions). The mechanistic study used one session of medical whole-body hyperthermia (protocol not given in the abstract).
What is still unknown
Controlled, blinded trials; outpatient feasibility; durability; use of standardized ME/CFS diagnostic criteria and outcome measures; risk of post-exertional symptom exacerbation.
Safety
Cautions for sauna in this condition
- The Waon protocol uses moderate temperature (140 F) with supine rest; higher-temperature sauna has not been studied in ME/CFS.
- Patients with orthostatic intolerance should start with short sessions and rise slowly afterward; antihypertensive drugs can predispose to post-bath orthostatic hypotension (PMID 16871826).
- See general-safety.
For clinicians
Suggested rationale
Small uncontrolled studies of far-infrared Waon therapy in chronic fatigue syndrome (Soejima 2015) reported reduced fatigue and improved mood and performance status without adverse effects; controlled trials are lacking.
Suggested wording only. The treating clinician decides whether it reflects their clinical judgment for this patient.
Typical ICD-10 codes: G93.3, G93.32. Examples only; the clinician assigns the code.
What a letter of medical necessity should containWho can write it: physicians, NPs, PAs and others