Long COVID and peptides — what the literature actually supports

Why this dossier exists

Long COVID — post-acute sequelae of SARS-CoV-2 infection (PASC), ICD-10 code U09.9 — is the condition where the gap between biohacker peptide protocols and published human evidence is wider than anywhere else in this corpus. The Davis, McCorkell, Vogel and Topol 2023 Nature Reviews Microbiology synthesis reported at least 10% of acute SARS-CoV-2 infections produce a long-COVID syndrome, more than 200 catalogued symptoms, an estimated 65 million affected globally. There is no FDA-approved disease-modifying treatment as of 2026; the NIH RECOVER initiative is only now beginning to read out RECOVER-TLC interventional trials, with most pivotal results not expected until late 2026 or 2027.

Into that vacuum the practitioner-peptide conversation has converged on a recognisable stack: Thymosin α-1 on immune-reconstitution, BPC-157 on gut-barrier and vascular repair, KPV on mast-cell and NF-κB modulation, and increasingly MOTS-c and SS-31 on the mitochondrial-dysfunction reading of post-exertional malaise. Two additional molecules have emerged in 2025–2026: ARA-290 / cibinetide on the dysautonomia and small-fiber-neuropathy axis, and the GLP-1 class (Semaglutide and tirzepatide) now in formal trial testing on a neuroinflammation hypothesis. This dossier walks each peptide against the actual literature, separates direct PASC evidence from mechanism extrapolation, and addresses the MCAS framing and the Kell-Pretorius microclot hypothesis that recur in long-COVID communities. The honest read: the strongest direct PASC evidence on this list is a single ex-vivo study with n=10 patients on thymosin α-1. Anyone using peptides for self-managed long COVID is operating downstream of mechanism plus practitioner observation, not downstream of trial evidence.