The Peptide Dosing Cheat Sheet
Mixing, units and the doses used in human studies for the 20 peptides people use most. Updated 4 Nov 2026.
1. MixAdd bacteriostatic water slowly down the side of the vial. Don't shake, swirl. 2 ml is the easy default.
2. Do the mathStrength = mg in the vial ÷ ml of water. 5 mg in 2 ml = 2.5 mg per ml = 25 mcg per unit on a U-100 syringe.
3. DrawUnits to draw = your dose in mcg ÷ mcg per unit. 250 mcg ÷ 25 = 10 units. Or let the calculator do it.
| Peptide | Common vials | 1 unit holds | Dose used in human studies | Half-life | People studied |
|---|---|---|---|---|---|
| RetatrutideFat loss | 5, 6, 8, 10, 12, 15 mg | 40 mcg8 mg vial + 2 ml | 4, 9 or 12 mg subcutaneously once weekly for 80 weeks in phase 3 (PMID 42814954). Read the article | About 6 days (phase 1b, PMID 36354040). | ~7,900 |
| GHK-CuHealing, Skin and hair | 5, 10, 20, 50, 80, 100 mg | 100 mcg20 mg vial + 2 ml | Topical only. Read the article | Not published. | ~350 |
| IpamorelinMuscle, Healing | 2, 5, 10, 12.5 mg | 25 mcg5 mg vial + 2 ml | 0.03 mg/kg IV twice daily for up to 7 days after bowel surgery (PMID 25331030). Read the article | About 2 hours after IV infusion in healthy men (PMID 10496658). | ~320 |
| BPC-157Healing, Gut | 5, 10, 15, 20, 25 mg | 75 mcg15 mg vial + 2 ml | Rectal enema: 0.25 to 2 mg/kg as one dose and, after a one-week break, once a day for 7 days, in 24 healthy volunteers, and 80 mg once a day for 2 weeks in people with ulcerative colitis (meeting abstracts, summarized by FDA in 2026). Read the article | No human value published. | ~84 |
| TesamorelinFat loss, Brain | 0.5, 2, 5, 10, 15, 20 mg | 25 mcg5 mg vial + 2 ml | 2 mg subcutaneously once daily for 26 to 52 weeks in the phase 3 trials (PMID 18057338). | About 11 minutes in healthy people after a subcutaneous dose (US Egrifta WR label). | ~1,338 |
| SemaxBrain, Mood | 5, 10, 25, 30, 50, 60 mg | 125 mcg25 mg vial + 2 ml | Russian label (Vidal page, registration of 26 March 2025), 0.1% drops: 50 mcg per drop, 2 to 3 drops per nostril, single dose 200 to 2,000 mcg. | No human plasma half-life is published. | ~500 |
| TB-500Healing | 2, 5, 10, 20, 25 mg | 50 mcg10 mg vial + 2 ml | Full-length Tβ4 only. Read the article | Not established in the sources checked. | None found |
| TirzepatideFat loss, Muscle | 5, 8, 10, 15, 20, 24 mg | 50 mcg10 mg vial + 2 ml | 5, 10 or 15 mg subcutaneously once weekly, reached through a 20 week step-up (SURMOUNT-1, PMID 35658024). | About 5 days (US Zepbound label). | ~17,372 |
| SelankBrain, Mood | 5, 6, 10, 20, 30, 40 mg | 50 mcg10 mg vial + 2 ml | Russian label: 0.15% nasal drops (1.5 mg per mL), 2 drops in each nostril 3 times a day for 14 days. | Very short. | ~240 |
| MOTS-cFat loss, Muscle | 5, 10, 15, 20, 30, 40 mg | 75 mcg15 mg vial + 2 ml | No human dose published. | Not published. | None found |
| CJC-1295 without DAC (Mod GRF 1-29)Muscle, Hormones | 2, 5, 10 mg | 25 mcg5 mg vial + 2 ml | No human dose published. | Not published. | None found |
| Melanotan IIFat loss, Skin and hair | 10, 17 mg | 50 mcg10 mg vial + 2 ml | 0.025 mg/kg under the skin as a single dose (about 1.75 to 2 mg for a 70 to 80 kg man) in the erectile dysfunction studies (PMID 9679884, PMID 11018622). | Not published. | ~23 |
| KPVGut | 4, 5, 10, 12, 12.5, 50 mg | 50 mcg10 mg vial + 2 ml | No human dose published. | Not published. | None found |
| SS-31Longevity | 5, 10, 20, 25, 30, 39 mg | 100 mcg20 mg vial + 2 ml | 40 mg subcutaneous once daily (Forzinity label, MMPOWER-3, TAZPOWER, ReCLAIM-2). | The US label gives no single half-life figure. | ~1,500 |
| SemaglutideFat loss | 2, 5, 6, 10, 12, 12.5 mg | 30 mcg6 mg vial + 2 ml | Subcutaneous 2.4 mg once weekly after a 16 week step-up (STEP 1, PMID 33567185). Read the article | About 1 week. | ~160,000 |
| SermorelinMuscle, Sleep | 2, 5, 10, 12 mg | 25 mcg5 mg vial + 2 ml | Children with GH deficiency: 30 mcg/kg subcutaneously once daily at bedtime (PMID 8772599). | Very short. | ~150 |
| Melanotan I (afamelanotide)Skin and hair | 10, 12, 13 mg | 60 mcg12 mg vial + 2 ml | Label: one 16 mg implant under the skin every 2 months (FDA Scenesse label). | Implant: apparent half-life about 15 hours, peak at a median 36 hours (FDA Scenesse label). | ~1,300 |
| DSIPHealing, Sleep | 2, 5, 7.5, 10 mg | 25 mcg5 mg vial + 2 ml | 1980s trials: 25 nmol per kg by slow intravenous injection, about 21 mcg per kg, once a day for 3 to 7 days (PMID 1299794, PMID 3583493), or 30 nmol per kg six times in a week (PMID 3792404). | Minutes. | ~240 |
| N-Acetyl Semax AmidateBrain | 10, 20, 30 mg | 100 mcg20 mg vial + 2 ml | No human dose published. | Not published. | None found |
| PT-141 (bremelanotide)Peptide | 10, 15 mg | 50 mcg10 mg vial + 2 ml | Label: 1.75 mg under the skin at least 45 minutes before sex, no more than one dose in 24 hours and no more than 8 doses a month (FDA Vyleesi label). | About 2.7 hours (range 1.9 to 4.0) after injection under the skin. | ~3,500 |
"Dose used in human studies" is what the trials gave, not a recommendation. "None found" means no published human study. Sources for every number are in the articles and in the Vault.
Want a protocol built for you?Protocols, the full Vault and live calls with Jan, inside the Room.
Join the Room