Short answer: A peptide half-life chart lists how long it takes for the amount of a peptide in the blood to fall by half. Published human half-lives range from about 8 minutes (tesamorelin) to about 1 week (semaglutide) and 7 to 8 days (cagrilintide). Most research peptides, including BPC-157 and TB-500, have no published human half-life at all.
Research info, not medical advice. A half-life describes how fast levels fall. It is not a dosing schedule, and most research peptides are not approved for human use.
Each value below comes from an FDA label or a human study, linked in the last column. The route matters: a peptide given into a vein usually clears faster than the same peptide injected under the skin, so the "Measured in" column says how each value was measured.
| Peptide | Half-life | Mostly gone (5 half-lives) | Measured in | Source |
|---|---|---|---|---|
| GLP-1 and amylin peptides | ||||
| Semaglutide Ozempic, Wegovy | About 1 week | About 35 days · curve | FDA label (Ozempic) | Ozempic label |
| Cagrilintide | About 7 to 8 days (159 to 195 hours) | About 33 to 41 days · curve | Phase 1b trial | Enebo 2021 |
| Retatrutide | About 6 days | About 30 days · curve | Phase 1b trial | Urva 2022 |
| Tirzepatide Mounjaro, Zepbound | About 5 days | About 25 days · curve | FDA label (Mounjaro) | Mounjaro label |
| Dulaglutide Trulicity | About 5 days | About 25 days · curve | FDA label (Trulicity) | Trulicity label |
| Liraglutide Victoza, Saxenda | About 13 hours | About 2.7 days · curve | FDA label (Saxenda) | Saxenda label |
| Exenatide Byetta | About 2.4 hours | About 12 hours | FDA label (Byetta) | Byetta injection label |
| Pramlintide Symlin | About 48 minutes | About 4 hours | FDA label (Symlin) | Symlin label |
| Growth hormone and GH-releasing peptides | ||||
| CJC-1295 with DAC | About 6 to 8 days (5.8 to 8.1 days) | About 29 to 41 days · curve | Study in healthy adults | Teichman 2006 |
| HGH (Somatropin) | About 2 to 4 hours | About 10 to 20 hours · curve | FDA labels, injection under the skin | Norditropin label, Genotropin label, Humatrope label |
| Ipamorelin | About 2 hours | About 10 hours · curve | Human study, given into a vein | Gobburu 1999 |
| Tesamorelin Egrifta | About 8 minutes | About 40 minutes · curve | FDA label (Egrifta SV) | Egrifta SV label, Egrifta WR label |
| Other peptides | ||||
| PT-141 (Bremelanotide) Vyleesi | About 2.7 hours | About 14 hours | FDA label (Vyleesi) | Vyleesi label |
| Thymosin Alpha-1 | About 2 hours | About 10 hours · curve | Published review | Review, Am J Health Syst Pharm 2001 |
| Teriparatide Forteo | About 1 hour | About 5 hours | FDA label (Forteo) | Forteo label |
| Abaloparatide Tymlos | About 1 hour | About 5 hours | FDA label (Tymlos) | Tymlos label |
For these, we found no study that measured a half-life in people after an injection under the skin. Numbers quoted online usually come from rats, from cells, or from giving the peptide into a vein. We list what is published and leave the half-life blank instead of guessing.
| Peptide | What is published |
|---|---|
| BPC-157 | No human data. In rats and dogs, given into a vein or muscle: under 30 minutes. |
| TB-500 | No human data for TB-500. Full-length thymosin beta-4 given into a vein: about 0.5 to 2 hours, but that is a different molecule. |
| CJC-1295 (no DAC) | No published human value. |
| Sermorelin | No value after an injection under the skin. A constant infusion into a vein in 10 men measured about 4.3 minutes. |
| Kisspeptin-10 | Into a vein only: about 4 minutes. No value after an injection under the skin. |
| GHRP-6 | Into a vein only: about 2.5 hours in nine healthy men. No value after an injection under the skin. |
| SS-31 (Elamipretide) | The FDA Forzinity label gives no half-life. Levels peak 0.5 to 1 hour after an injection under the skin. |
| GHRP-2 | No published human value. |
| IGF-1 LR3 | No published human value. |
| GHK-Cu | No published human value. |
| Melanotan II | No published human value. |
| AOD-9604 | No published human value. |
| MOTS-c | No published human value. |
| Semax | No published human value. |
| Selank | No published human value. |
| KPV | No published human value. |
| DSIP (Delta Sleep-Inducing Peptide) | No published human value. |
| Epitalon | No published human value. |
| LL-37 | No published human value. |
After one half-life, about half of a dose is left in the blood. After two, about a quarter. After five, about 3% is left, which is why "5 half-lives" is the usual rule for when a drug is mostly gone. With regular dosing, levels also take about 5 half-lives to level off (steady state). The Ozempic label puts it this way for semaglutide: with a half-life of about 1 week, it is present in the circulation for about 5 weeks after the last dose.
To see the curve for a schedule, use the half-life calculator. For the idea in more depth, read understanding half-life. For mixing a vial, see the peptide reconstitution calculator and how to reconstitute peptides.