Astressin-B is a synthetic cyclic peptide antagonist of corticotropin-releasing factor (CRF) receptors, originally developed for stress-related research. It gained viral attention after a 2011 Salk Institute study showed that a single injection reversed hair loss in chronically stressed mice. The hair regrowth finding was serendipitous — the study was designed to investigate stress-related GI effects. Despite enormous public interest, no human clinical trials for hair growth have been conducted, and CRF antagonists have a troubled clinical development history for psychiatric indications.
Category: Stress / CRF Antagonist. Evidence rating: D (animal/preclinical only).
Clinical status: Preclinical only. No human clinical trials. Multiple CRF1-selective antagonists have failed in clinical trials for depression and anxiety.
Astressin-B is a non-selective CRF receptor antagonist that blocks both CRF1 and CRF2 receptors. CRF is the master regulator of the stress response, activating the HPA axis and peripheral stress pathways. By blocking CRF receptors in the skin, astressin-B may reverse stress-induced telogen…
Safety considerations: No human safety data exists; CRF receptor antagonism could impair the stress response, which is physiologically essential; Related CRF1-selective antagonists in clinical trials showed hepatotoxicity and limited efficacy.
Reviewed by the PeptideAtlas Editorial Team.
| Molecular weight | ~3600 g/mol (approximate) |
|---|---|
| Production method | synthetic |
| Anti-doping status | not-listed |
| US regulatory status | Not FDA-approved. Research peptide only. |
The mouse study used a specific genetic model of CRF overexpression that caused stress-related hair loss. There is no evidence it would work for common androgenetic alopecia (male/female pattern baldness) or other forms of hair loss. No human trials exist.
CRF receptor antagonists have a troubled history — multiple compounds failed in clinical trials for depression and anxiety due to limited efficacy and liver toxicity. The hair growth finding was serendipitous and has not attracted pharmaceutical investment for clinical development.
No. Astressin-B is a non-selective peptide antagonist blocking both CRF1 and CRF2 receptors. Most clinical candidates (pexacerfont, verucerfont) were CRF1-selective small molecules. The non-selectivity and peptide nature of astressin-B make it distinct.
The CRF-mediated stress response is essential for survival. Chronic blockade could impair the ability to respond to physical stressors, potentially causing adrenal insufficiency. This is a fundamental limitation of the CRF antagonist approach.