Peptide Half-Life Chart: Compare Common Peptides by Duration
This peptide half-life chart compares common research peptides by approximate duration so you can quickly see which compounds are discussed as shorter- or longer-acting. Half-life is a practical reference for understanding exposure, comparison context, and research planning. Use the linked guides, calculators, and protocol pages below for deeper context. Educational and research only, not medical advice.
Peptide Half-Life Chart
Half-life values can vary across studies, formulations, route of administration, and research conditions. Use this chart as a practical reference and verify critical details against primary literature.
| Peptide | Approximate Half-Life | Category | Research Context | Related Guide |
|---|---|---|---|---|
| Semaglutide | Approximately 7 days (long-acting). | Long-acting GLP-1 analog | Long-duration incretin signaling and weekly research cadence discussions. | Semaglutide guide |
| Tirzepatide | Approximately 5 days (long-acting). | Long-acting dual incretin analog | GLP-1/GIP comparison work and weekly titration-oriented protocol research. | Tirzepatide guide |
| Retatrutide | Approximately 6 days (long-acting). | Extended-duration triple agonist analog | Long-acting GLP-1/GIP/glucagon comparison and protocol-planning context. | Retatrutide guide |
| CJC-1295 | With DAC: ~8 days. Without DAC: ~30 minutes. | GHRH analog | Formulation-dependent GH signaling research; DAC and non-DAC versions differ materially. | CJC-1295 guide |
| Ipamorelin | Approximately 2 hours. | GH secretagogue | Shorter-duration GH pulse discussions and timing-sensitive research frameworks. | Ipamorelin guide |
| BPC-157 | Short; often dosed daily or twice daily in research. | Tissue-repair research peptide | Repair and gut-focused research discussions where exact human PK remains uncertain. | BPC-157 guide |
| TB-500 | Short; dosing frequency varies in research. | Thymosin beta-4-related peptide | Cell-migration and connective-tissue research with non-standardized PK reporting. | TB-500 guide |
| GHK-Cu | Short; rapid metabolism typical of small peptides. | Copper peptide | Skin, collagen, and topical-versus-injectable research discussions. | GHK-Cu guide |
| MOTS-c | Not fully established in humans; preclinical data suggests relatively short. | Mitochondria-derived peptide | Metabolic research where human pharmacokinetic detail remains limited. | MOTS-c guide |
What Peptide Half-Life Means
Half-life, simply explained
Half-life is how long it takes for about half of a peptide to leave the body.
Simple example
If a peptide starts at 100%, then after one half-life about 50% is left. After two half-lives, about 25% is left. After three half-lives, about 12.5% is left.
100% → 50% → 25% → 12.5%
Each step represents one half-life.
Half-life is not the same as completely gone
A 6-day half-life does not mean a peptide is fully gone after 6 days. It means about half may still remain around that point.
Example: Retatrutide
If Retatrutide is discussed with a reported half-life of about 6 days, that means roughly half may still be present after about 6 days. It does not mean the compound is fully cleared. That is one reason it has been studied as a once-weekly compound.
What happens if another dose is given around day 6?
A simple teaching example looks like this:
- Day 0: 100%
- Day 6: about 50% left
- Day 6 or 7: next dose given
- Simplified total right after that dose: about 150% of the original single-dose amount
Some of the earlier dose is still present, so the next dose builds on what remains. That is normal with repeated dosing and does not automatically mean anything is wrong or dangerous. It is part of how longer-acting compounds maintain steadier levels over time.
Half-Life and Research Planning
Comparing short- and long-half-life peptides
A short-half-life peptide leaves the body faster, so its levels usually drop more quickly. A long-half-life peptide stays in the body longer, so its levels usually fall more slowly over time.
- short half-life = faster drop
- long half-life = slower drop
This can affect how a compound is discussed in research planning. Shorter-acting compounds are often associated with tighter timing, while longer-acting compounds are often associated with wider spacing and steadier levels over time.
Why some peptides last longer
Not all peptides stay in the body for the same amount of time. Some are cleared more quickly, while others are designed or modified to last longer.
In simple terms, this can depend on a few things:
- the peptide's structure
- how stable it is in the body
- how quickly the body breaks it down
- how it is formulated
Why structure, formulation, and route matter
Half-life is not only about the peptide name itself. It can also be affected by the details of the compound and how it is used in a study.
- structure — small changes in the molecule can change how long it lasts
- formulation — different versions of a compound may behave differently
- route of administration — how a compound is given can affect how quickly it enters and leaves the body
This is one reason half-life values are often approximate rather than exact.
Why this matters in research planning
Understanding half-life helps people compare compounds more clearly.
For example, a shorter-acting peptide may be associated with levels that rise and fall more quickly. A longer-acting peptide may be associated with levels that change more slowly over time.
That helps researchers think about timing, spacing, and how consistent levels may be over a period of days.
Simple takeaway
Half-life helps answer a basic question: How quickly does the amount of this peptide go down over time?
That makes half-life one of the most useful ways to compare peptides in a simple, beginner-friendly way.
Half-Life and Pharmacokinetics
Elimination half-life is one pharmacokinetic metric inside a larger picture. It helps describe concentration decay over time, but it does not capture every variable that shapes exposure.
In practical terms, repeated administrations can create accumulation until a steadier pattern is reached. That is why steady-state discussions matter more for some long-acting analogs than for shorter compounds with faster concentration decline.
Pharmacokinetic context also matters when comparing literature. Study route, assay timing, formulation details, and the population being studied can materially shift the half-life reported in a paper or summary.
Short vs Long Half-Life Peptides
Ultra-short
Often measured in minutes to a few hours. These compounds are usually discussed in timing-sensitive research contexts rather than long-interval schedules.
Short
Short-half-life peptides still clear relatively quickly, so researchers usually interpret them through exposure windows rather than extended carryover.
Medium
Medium-duration compounds sit between pulse-like exposure and long-acting analog behavior. Their interpretation often depends heavily on formulation and route.
Long
Long-half-life peptides are usually easier to compare in weekly or less-frequent planning discussions, but steady-state and accumulation become more relevant.
Extended-duration analogs
Engineered analogs can stay active in circulation much longer than native molecules. Those modifications change both research planning context and comparison logic.
Use PeptideUniv Tools for Research Organization
PeptideUniv combines calculators, saved protocols, reminders, and organized research workflows so you can move from reference reading into structured planning without losing context.
Start with the calculator for concentration math, then save protocol ideas and keep recurring research tasks organized inside the full workspace.
FAQ
What is peptide half-life?
Why do peptide half-lives vary?
Is half-life the same as duration of effect?
Why do modified peptides last longer?
Where can I find calculators and peptide guides?
Related Links
For educational and research purposes only. Not medical advice. Consult a licensed healthcare professional for personal guidance.