Side by side
MK-677 vs PT-141
Both are discussed for muscle & performance. What this site records about each, side by side. Every figure is on the compound's own page with the source it came from.
| MK-677 | PT-141 | |
|---|---|---|
| What it is | An orally active ghrelin receptor agonist that raises growth hormone and IGF-1. Not a peptide, and not injected. It is a small molecule taken by mouth. | A melanocortin receptor agonist approved by the FDA for low sexual desire in premenopausal women. It acts on the brain rather than on blood flow. |
| EvidenceHow much human evidence exists, not how well it works. | Early human trials | Approved for another indication |
| Regulatory statusReviewed 2026-08-12 | Not approved for human use in any jurisdiction. Development was not completed. It is widely sold as a 'research chemical' or mislabelled as a dietary supplement, which it is not. It is an unapproved drug. | Approved by the FDA as a prescription medicine for hypoactive sexual desire disorder in premenopausal women. It is not approved for use in men, and material sold as a research chemical is not the approved product. |
| Routes | Oral | Subcutaneous, Nasal |
| Half-life | 24 hours | 2.7 hours |
| Cheapest per mgVials only, read from vendors' own listings and dated on the price index. | $0.64/mg | $1.88/mg |
| Median per mg | $2.94/mg | $4.00/mg |
| Vendors with a price | 6 | 49 |
| Storage once mixed | Not applicable. Liquid preparations sold in solution should follow the seller's storage instructions, which is a weaker guarantee than it sounds. | Refrigerated at 2–8 °C. Do not freeze once mixed. |
Compare two other compounds · The full price index
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on BioAlmanac is medical advice. Nothing here ranks these two against each other. A table can show that one has more human evidence behind it or costs less per milligram; neither of those is a recommendation, and the right comparison for any person is one their doctor makes with them.