Plasma half-life cheat-sheet
Approximate t½ values reported in published pharmacokinetic studies. Subcutaneous route unless noted.
Grouped overview
Short< 1 hour
GHRP-2, GHRP-6, Ipamorelin, Hexarelin · ~15–30 min ·
Sermorelin ~10–15 min ·
PT-141 ~30–120 min ·
Selank, Semax < 30 min (intranasal route).
Medium1–12 hours
BPC-157 ~4 hours ·
TB-500 ~2–3 hours ·
Tesamorelin ~26 minutes (active metabolite ~38 minutes; effective signalling longer) ·
GHK-Cu ~few hours topical / 2 hours IV.
Long12 h – 1 week
CJC-1295 with DAC ~6–8 days ·
CJC-1295 (no DAC) ~30 minutes ·
Semaglutide ~7 days ·
Tirzepatide ~5 days ·
Retatrutide ~6 days ·
MK-677 (Ibutamoren) ~24 hours.
Detailed table
| Compound | Class | t½ (approx) | Route |
|---|---|---|---|
| Sermorelin | GHRH | 10–15 min | SC |
| GHRP-6 | GHRP | 15–30 min | SC |
| Ipamorelin | GHRP | ~2 h (terminal) | SC |
| CJC-1295 (no DAC) | GHRH analogue | ~30 min | SC |
| CJC-1295 (with DAC) | GHRH analogue | ~6–8 days | SC |
| Tesamorelin | GHRH analogue | ~26 min (parent) | SC |
| BPC-157 | Pentadecapeptide | ~4 h | SC / oral |
| TB-500 | Thymosin-β4 fragment | ~2–3 h | SC |
| Semaglutide | GLP-1 RA | ~7 days | SC |
| Tirzepatide | GLP-1 / GIP RA | ~5 days | SC |
| Retatrutide | GLP-1 / GIP / GCG | ~6 days | SC |
| MK-677 (Ibutamoren) | Ghrelin agonist | ~24 h | Oral |
| Selank | Heptapeptide | < 30 min | IN |
| Semax | Heptapeptide | < 30 min | IN |
| PT-141 (Bremelanotide) | Melanocortin RA | ~30–120 min | SC / IN |
| Melanotan II | Melanocortin RA | ~30 min | SC |
| GHK-Cu | Tripeptide | ~2 h IV / hours topical | Topical / SC |
| Epithalon | Tetrapeptide | ~5–30 min (terminal) | SC |
Values are reported ranges from published pharmacokinetic literature; actual t½ varies with route, formulation and assay model.