Anamorelin is a synthetic, orally active ghrelin receptor (GHS-R1a) agonist developed for the treatment of cancer-related cachexia. Unlike endogenous ghrelin which has a half-life of minutes, anamorelin was designed for once-daily oral administration with sustained receptor activation. It received regulatory approval in Japan in 2021 for cancer cachexia in patients with NSCLC, gastric, pancreatic, and colorectal cancer — making it one of very few peptide-derived therapeutics with a specific cachexia indication. It has not been approved by the FDA or EMA.
Category: Growth Hormone Secretagogue. Evidence rating: B (meaningful human data).
Clinical status: Approved in Japan (2021) for cancer cachexia. Phase III trials completed (ROMANA 1 & 2). Not FDA/EMA approved.
Anamorelin acts as a selective agonist at GHS-R1a, the same G protein-coupled receptor targeted by endogenous ghrelin. In the hypothalamus, GHS-R1a activation stimulates orexigenic neurons in the arcuate nucleus, increasing NPY/AgRP signaling and suppressing anorexigenic POMC pathways, producing…
Safety considerations: Phase III trials (ROMANA) showed discontinuation rates comparable between anamorelin and placebo groups; GH-mediated blood glucose elevation observed; diabetes mellitus or glucose intolerance in small percentage; Transient liver enzyme elevations (AST, ALT) reported, typically mild and reversible.
Reviewed by the PeptideAtlas Editorial Team.
| Molecular formula | C35H46N8O5 |
|---|---|
| Molecular weight | 658.79 g/mol |
| CAS number | 249921-19-5 |
| Half-life | 7-12 hours |
| Bioavailability | Orally bioavailable (peptidomimetic design) |
| Production method | synthetic |
| Anti-doping status | not-listed |
| US regulatory status | Not FDA-approved. Phase III trials completed but not submitted for approval due to functional endpoint concerns. |
Related peptides: Ipamorelin, CJC-1295, Sermorelin.
No. Anamorelin is approved only in Japan (2021) for cancer cachexia. It has not received FDA or EMA approval, partly due to concerns about the dissociation between lean mass gains and functional strength improvements, and QTc prolongation.
Anamorelin is orally active with a 7-12 hour half-life, while GHRP-2 and ipamorelin require injection and have much shorter half-lives (15-30 minutes). All target GHS-R1a but anamorelin is a peptidomimetic small molecule rather than a true peptide.
Cancer cachexia is a multi-organ syndrome of involuntary weight loss, skeletal muscle wasting, and reduced appetite that cannot be fully reversed by nutritional support. It affects 50-80% of advanced cancer patients and is associated with reduced treatment tolerance and survival.
While ROMANA trials met primary endpoints for lean mass, they failed to show improvement in handgrip strength (a co-primary endpoint). The FDA weighed this functional disconnect along with QTc prolongation concerns.
Coverage on this site: Ipamorelin Handling: Storage, Documentation, and Best Practices, Ipamorelin Stability: What Researchers Should Know.