Peptide Half-Life Calculator
Visualize and compare how different peptides decay over time. Understanding half-life is crucial for determining optimal dosing frequency and maintaining therapeutic levels.
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What is Half-Life?
Half-life (t1/2) is the time it takes for the concentration of a substance in the body to reduce by 50%. This pharmacokinetic parameter is fundamental to understanding how long a peptide remains active in the system.
Key Points:
- After 1 half-life: 50% remains
- After 2 half-lives: 25% remains
- After 3 half-lives: 12.5% remains
- After 4-5 half-lives: Essentially eliminated
Peptides with longer half-lives require less frequent dosing but may accumulate with repeated doses. Shorter half-life peptides clear quickly and often require multiple daily doses.
Why Half-Life Matters
Dosing Frequency
Determines how often a peptide should be administered to maintain effective levels in research subjects.
Steady State
Helps predict when drug levels will stabilize with repeated dosing (typically 4-5 half-lives).
Redosing Window
Identifies the optimal time to administer the next dose (usually between 1-2 half-lives).
Drug Testing
Indicates how long a substance may be detectable in the system.
Route of Administration
Half-life values shown are typically for subcutaneous (SubQ) administration. Intravenous (IV) administration often results in shorter half-lives due to faster absorption, while intramuscular (IM) may show intermediate values.
Peptide Half-Life Categories
Short (< 6 hours)
Requires multiple daily doses. Clear quickly, less accumulation risk.
Medium (6-24 hours)
Once or twice daily dosing. Good balance of convenience and control.
Long (> 24 hours)
Less frequent dosing (weekly or less). May accumulate with repeated doses.
Complete Peptide Half-Life Reference
| Peptide | Half-Life | Confidence | Category | Typical Dosing | Source |
|---|---|---|---|---|---|
| VIP | 1-2 minutes (plasma) | Low | Immune & Inflammation | 2-3x daily | - |
| Angiotensin II | 1-2 minutes | Low | Cardiovascular | 2-3x daily | - |
| Gonadorelin | 2-4 minutes | Low | Hormonal & Sexual Health | 2-3x daily | - |
| Oxytocin | 3-5 minutes (plasma) | Low | Cognitive & Nootropic | 2-3x daily | - |
| MGF | 5-7 minutes | Low | Muscle Growth | 2-3x daily | - |
| Pinealon | Short (minutes) | Low | Nootropic & Cognitive | 2-3x daily | - |
| Vasopressin | 10-20 minutes | Low | Cardiovascular | 2-3x daily | - |
| BNP | 20 minutes | Low | Cardiovascular | 2-3x daily | - |
| DSIP | 15-25 minutes | Low | Nootropic & Sleep | 2-3x daily | - |
| AOD-9604 | 30 minutes | Low | Healing & Recovery | 2-3x daily | - |
| CJC-1295 no DAC | 30 minutes | Low | Growth Hormone | 2-3x daily | - |
| Fragment 176-191 | 30-60 minutes | Low | Metabolic & Fat Loss | 2-3x daily | - |
| Glycine | 30-60 minutes | Low | Antimicrobial | 2-3x daily | - |
| Humanin | 30 minutes | Low | Mitochondrial | 2-3x daily | - |
| Thymulin | 15-30 minutes | Low | Immune | 2-3x daily | - |
| Thymosin Beta-4 | 30-60 minutes | Low | Healing & Recovery | 2-3x daily | - |
| Pramlintide | 48 minutes | Low | Metabolic & Fat Loss | 2-3x daily | - |
| Hexarelin | 70 minutes | Low | Growth Hormone | 2-3x daily | - |
| Buserelin | 1-2 hours | Low | Hormonal | 2-3x daily | - |
| PE-22-28 | 1-2 hours | Low | Cognitive & Nootropic | 2-3x daily | - |
| Collagen Peptides | Not well characterized | Low | Hair & Skin | 2-3x daily | - |
| Copper Tripeptide-1 | Not yet established in human studies | Low | Hair & Skin | 2-3x daily | - |
| Defensin HBD-2 | Not yet established in human studies | Low | Antimicrobial | 2-3x daily | - |
| Desmopressin | 1.5-2.5 hours | Low | Hormonal | 2-3x daily | - |
| Ipamorelin | 2-3 hours | Medium | Growth Hormone | 2-3x daily | Raun et al., Eur J Endocrinol 1998 |
| Nisin | Not yet established in human studies | Low | Antimicrobial | 2-3x daily | - |
| Exenatide | 2.4 hours (immediate-release), 2 weeks (extended-release) | Low | Metabolic & Fat Loss | 2-3x daily | - |
| Angiotensin 1-7 | 2-4 hours | Low | Cardiovascular | 2-3x daily | - |
| Argireline | 2-4 hours topically | Low | Hair & Skin | 2-3x daily | - |
| GHK | 2-4 hours | Low | Anti-Aging | 2-3x daily | - |
| Larazotide | 2-4 hours (local gut activity) | Low | Gut & Digestive | 2-3x daily | - |
| Leuprolide | 2.9-4.2 hours | Low | Hormonal | 2-3x daily | - |
| N-Acetyl Selank Amidate | 2-4 hours | Low | Cognitive & Nootropic | 2-3x daily | - |
| Nafarelin | 2-4 hours | Low | Fertility & Hormones | 2-3x daily | - |
| BPC-157 | 4-6 hours | Medium | Healing & Recovery | 2-3x daily | Sikiric et al., J Physiol Paris 1999 |
| N-Acetyl Semax Amidate | 3-5 hours | Low | Cognitive & Nootropic | 2-3x daily | - |
| SS-31 | 4 hours | Low | Mitochondrial | 2-3x daily | - |
| Triptorelin | 3-5 hours (immediate release), 4 weeks (depot) | Low | Hormonal | 2-3x daily | - |
| Goserelin | 2.3 hours (initial), 4.2 hours (terminal) | Low | Hormonal | 2-3x daily | - |
| Pentadecapeptide BPC | 4-6 hours | Low | Healing & Recovery | 2-3x daily | - |
| SNAP-8 | 4-6 hours (topical residence) | Low | Hair & Skin | 2-3x daily | - |
| Polymyxin B | 4.3-6 hours | Low | Antimicrobial | 2-3x daily | - |
| Kisspeptin-54 | 4-8 hours | Low | Fertility & Hormones | 1-2x daily | - |
| MOTS-c | Unknown (estimated 4-8 hours) | Low | Mitochondrial | 1-2x daily | - |
| Pentosan Polysulfate | 4-8 hours | Low | Anti-Aging | 1-2x daily | - |
| TB-500 | 24-48 hours | Medium | Healing & Recovery | 1-2x daily | Goldstein et al., Expert Opin Biol Ther 2012 |
| Matrixyl | 6-8 hours (skin residence) | Low | Hair & Skin | 1-2x daily | - |
| Liraglutide | 13 hours | High | Metabolic & Fat Loss | 1-2x daily | FDA Label (Saxenda) |
| Myostatin | Variable by compound | Low | Muscle Growth | 1-2x daily | - |
| Orforglipron | 29-49 hours | Low | Metabolic & Fat Loss | 2-3x weekly | - |
| Pemvidutide | 72-96 hours | Low | Metabolic & Fat Loss | Weekly or less | - |
| Dulaglutide | 5 days | Low | Metabolic & Fat Loss | Weekly or less | - |
| Enclomiphene | 5-7 days | Low | Hormonal | Weekly or less | - |
| PEG-MGF | 5-7 days | Low | Muscle Growth | Weekly or less | - |
| Cagrilintide | ~165 hours (7 days) | Low | Metabolic & Fat Loss | Weekly or less | - |
| ACE-031 | 11-14 days | Low | Muscle Growth | Weekly or less | - |
| Cerebrolysin | Variable (peptide mixture) | Low | Nootropic & Cognitive | Weekly or less | - |
| CJC-1295 with DAC | 6-8 days | Medium | Growth Hormone | Weekly or less | - |
| Mazdutide | 168 hours (7 days) | Low | Metabolic & Fat Loss | Weekly or less | - |
| Retatrutide | 168 hours (7 days) | Low | Metabolic & Fat Loss | Weekly or less | - |
| Semaglutide | 7 days | High | Fat Loss & Metabolic | Weekly or less | FDA Label (Ozempic) |
| Survodutide | 168 hours (7 days) | Low | Metabolic & Fat Loss | Weekly or less | - |
| Thymalin | Short | Low | Immune & Longevity | Weekly or less | - |
IMPORTANT: Research & Educational Use Only
This half-life calculator is strictly for educational and research reference purposes. Half-life values are compiled from published literature and may vary based on route of administration, individual metabolism, and study methodology.
Not Medical Advice: The dosing frequency suggestions are general guidelines based on pharmacokinetic principles and do not constitute medical advice. Always consult qualified healthcare professionals for medical decisions.
Data Sources: Half-life data is derived from peer-reviewed literature and clinical studies where available. Individual responses may vary significantly based on factors including age, weight, organ function, and concurrent medications.
Disclaimer: PepGuide and its contributors assume no liability for decisions made based on this information. Many peptides discussed are research compounds not approved for human therapeutic use.