Peptide Half-Life Chart
How long each peptide stays active after injection — half-life, time to clearance, route, and typical dosing frequency in one reference table, plus an interactive decay curve.
| Peptide | Half-life | ~Cleared (5×) | Route | Typical dosing |
|---|---|---|---|---|
| Sermorelin | ~10 min | ~51 min | SubQ | ~10 min — immediate pulse, bedtime dosing |
| CJC-1295 (no DAC) | ~30 min | 2.5 hours | SubQ | Minutes in circulation — rapid pulsatile GH release |
| GHK-Cu | 1 hour | 5 hours | SubQ / topical | Short — rapid tissue uptake |
| Ipamorelin | 2 hours | 10 hours | SubQ | Very short — pulse dosing 2–3× daily |
| SS-31 (Elamipretide) | 2 hours | 10 hours | SubQ / IV | Rapid clearance — daily dosing in studies |
| PT-141 (Bremelanotide) | 2.5 hours | 12.5 hours | SubQ / nasal | Dose 45–60 min before activity |
| Epithalon | 3 hours | 15 hours | SubQ / IV | Short — typically dosed daily in cycles |
| BPC-157 | 4 hours | 20 hours | SubQ / IM | Short half-life — typically dosed 1–2× daily |
| MOTS-c | 6 hours | 30 hours | SubQ / IV | Estimated based on metabolic clearance data |
| TB-500 | 24 hours | ~5 days | SubQ / IM | Often dosed 2× weekly |
| Semaglutide | ~7 days | ~35 days | SubQ | ~7 days — once weekly injection |
| Retatrutide | ~7 days | ~35 days | SubQ | ~7 days — once weekly per Phase 2 trial |
| CJC-1295 (with DAC) | ~8 days | ~40 days | SubQ | ~8 days — once or twice weekly dosing |
Interactive decay curve
Select a compound to see its decay curve, or add a second to compare two peptides side by side.
BPC-157
Half-life: 4h·SubQ / IM
BPC-157: Short half-life — typically dosed 1–2× daily
How to read peptide half-life
A peptide's half-life is the time it takes for half of the dose to be cleared from circulation. It is the single most important number for planning dosing frequency: after one half-life ~50% remains, after two ~25%, and after about five half-lives a peptide is ~97% cleared and considered effectively gone.
This is why dosing schedules vary so widely. A peptide like Sermorelin or CJC-1295 without DAC clears in minutes and is dosed daily (often at bedtime to mimic natural growth-hormone pulses), while Semaglutide and Retatrutide persist for about a week and are injected just once weekly. Matching dosing interval to half-life keeps levels steady and avoids peaks and troughs.
One caveat: circulating half-life is not always the same as duration of effect. Some peptides act locally in tissue or trigger downstream signaling that outlasts measurable blood levels — BPC-157 is a commonly cited example. Use half-life as a dosing-frequency guide, not a strict measure of how long a biological effect lasts.
Turn frequency into a dose
Once you know how often to dose, the dosing calculator converts your target dose and vial concentration into exact units to draw on a U-100 insulin syringe.
Open the dosing calculatorFrequently Asked Questions
What is a peptide half-life?
A peptide's half-life is the time it takes for half of the administered amount to be cleared from circulation. After one half-life, ~50% remains; after two, ~25%; after five half-lives a peptide is roughly 97% cleared and considered effectively eliminated. Half-life is the key factor in how often a peptide needs to be dosed.
How does half-life determine dosing frequency?
Short half-life peptides (minutes to a few hours), like CJC-1295 without DAC, Ipamorelin, or Sermorelin, are dosed one or more times per day to maintain effect. Long half-life peptides, like Semaglutide, Retatrutide, and CJC-1295 with DAC (~7–8 days), are dosed once weekly because they persist in circulation far longer.
How long does BPC-157 stay in your system?
BPC-157 has a short circulating half-life of roughly 4 hours, so it is typically dosed once or twice daily. Note that circulating half-life and duration of biological effect are not always identical — local tissue effects may outlast measurable blood levels.
Why do Semaglutide and Retatrutide only need weekly dosing?
Both have a half-life of approximately 7 days (168 hours), achieved through structural modifications (such as albumin binding) that slow clearance. This long half-life is what allows once-weekly subcutaneous injection while maintaining steady drug levels.
What does "5 half-lives" mean for clearance?
The "5 half-lives" rule is a standard pharmacology guideline: after five half-lives, about 97% of a compound has been eliminated, so it is treated as effectively cleared. For a 4-hour half-life peptide that is ~20 hours; for a 7-day half-life peptide it is roughly 5 weeks.