Peptides for Chronic Fatigue & CFS/ME

Peptides may theoretically address ME/CFS pathophysiology through several mechanisms, though evidence is largely preclinical and speculative:

1. Mitochondrial Function Enhancement Mitochondrial dysfunction is increasingly recognised in ME/CFS — studies have demonstrated impaired oxidative phosphorylation, reduced ATP production, and abnormal mitochondrial membrane potential in patient samples. MOTS-c, a 16-amino-acid peptide encoded by mitochondrial DNA, activates the AMPK pathway and has demonstrated metabolic regulatory effects including improved glucose uptake and fatty acid oxidation in preclinical models. SS-31 (elamipretide) targets the inner mitochondrial membrane, stabilising cardiolipin and improving electron transport chain efficiency. These mitochondrial peptides address the bioenergetic deficit hypothesis of ME/CFS directly.

2. Immune System Rebalancing ME/CFS is characterised by immune dysregulation including altered natural killer (NK) cell function, shifted T-cell subsets, elevated inflammatory cytokines, and in some patients, evidence of chronic immune activation. Thymosin-alpha-1, a thymic peptide that modulates T-cell maturation, NK cell activity, and dendritic cell function, has been used in clinical practice for immunodeficiency and chronic viral infections. Its immunomodulatory properties may be relevant to the immune dysregulation observed in ME/CFS, particularly in post-viral presentations.

3. Cellular Stress Response Support Humanin, a 24-amino-acid mitochondrial-derived peptide, has demonstrated cytoprotective effects including protection against oxidative stress, endoplasmic reticulum stress, and apoptosis. In ME/CFS, cellular stress responses appear to be chronically activated, potentially contributing to the inability to recover from exertion. Humanin's cytoprotective and anti-inflammatory properties may theoretically support cellular resilience, though this is entirely speculative in the ME/CFS context.

4. Post-Viral Recovery Support The association between viral infections and ME/CFS onset — now reinforced by the long COVID experience — has focused attention on immunomodulatory approaches. Thymosin-alpha-1 has clinical evidence for supporting immune recovery from chronic viral infections (hepatitis B, hepatitis C) and has been used as an adjunctive therapy in immunocompromised patients. Its ability to enhance adaptive immunity whilst modulating excessive inflammation may be relevant to post-viral fatigue states, though it has not been specifically studied in ME/CFS or long COVID.

5. Hormonal and Metabolic Support Many ME/CFS patients demonstrate hormonal abnormalities including blunted HPA axis responses, reduced growth hormone secretion, and altered thyroid function. GH secretagogues such as CJC-1295 may support GH-IGF-1 axis function, which influences energy metabolism, body composition, and tissue repair. However, hormonal supplementation in ME/CFS is controversial, and the relationship between observed hormonal changes and symptom causation remains unclear — hormonal abnormalities may be consequences rather than causes of the condition.