What Is PT-141?
PT-141 (Bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH). Developed from Melanotan II, PT-141 lacks the C-terminal amide group, selectively activating central melanocortin MC3R and MC4R receptors in the hypothalamus without stimulating cutaneous melanogenesis.
In clinical and preclinical research, PT-141 is evaluated for central nervous system-mediated arousal and sexual dysfunction in both male and female models. PT-141 has an elimination half-life of approximately 2.7 hours. Other central peptides evaluated in laboratory studies include Mots-c and KPV. Reconstituting PT-141 with our peptide calculator and bacteriostatic water ensures exact volumetric measurement.
In clinical and preclinical research, PT-141 is evaluated for central nervous system-mediated arousal and sexual dysfunction in both male and female models. PT-141 has an elimination half-life of approximately 2.7 hours. Other central peptides evaluated in laboratory studies include Mots-c and KPV. Reconstituting PT-141 with our peptide calculator and bacteriostatic water ensures exact volumetric measurement.
PT-141 Dosage Chart
Standard research protocols for PT-141 evaluate doses between 1.0 mg and 2.0 mg (with 1.75 mg being the FDA-approved Bremelanotide clinical benchmark). Reconstituting a 10 mg vial with 2.0 mL of bacteriostatic water creates a concentration of 5.0 mg/mL.
Vial: 5 mgWater: 2.0 mL
Concentration2.5 mg/mL
Target Dose1.0 mg (1,000 mcg)
Draw to Mark:40.0 Units
Vial: 10 mgWater: 2.0 mL
Concentration5.0 mg/mL
Target Dose1.0 mg (1,000 mcg)
Draw to Mark:20.0 Units
Vial: 10 mgWater: 2.0 mL
Concentration5.0 mg/mL
Target Dose1.75 mg (1,750 mcg)
Draw to Mark:35.0 Units
Vial: 10 mgWater: 2.0 mL
Concentration5.0 mg/mL
Target Dose2.0 mg (2,000 mcg)
Draw to Mark:40.0 Units
| Vial Size | Bac Water Added | Concentration | Target Research Dose | Draw Units (U-100) |
|---|---|---|---|---|
| 5 mg | 2.0 mL | 2.5 mg/mL | 1.0 mg (1,000 mcg) | 40.0 Units |
| 10 mg | 2.0 mL | 5.0 mg/mL | 1.0 mg (1,000 mcg) | 20.0 Units |
| 10 mg | 2.0 mL | 5.0 mg/mL | 1.75 mg (1,750 mcg) | 35.0 Units |
| 10 mg | 2.0 mL | 5.0 mg/mL | 2.0 mg (2,000 mcg) | 40.0 Units |
How to Reconstitute PT-141
Reconstituting PT-141 requires standard laboratory diluent procedures to dissolve the lyophilized cyclic peptide cake into a sterile aqueous solution.
Syringe Reading Diagram
U-100 Syringe Graduation & Measurement Line (PT-141)
5 Standard Reconstitution Steps for PT-141
- Clean the rubber stoppers of both vials with fresh 70% isopropyl alcohol swabs.
- Draw 2.0 mL of sterile bacteriostatic water into a syringe.
- Inject water slowly down the internal glass wall of the PT-141 vial.
- Swirl gently until completely clear. Do not shake.
- Refrigerate reconstituted PT-141 at 2°C–8°C.
❄️ Storage & Shelf-Life Notice (PT-141)
Reconstituted PT-141 prepared with 0.9% benzyl alcohol bacteriostatic water remains stable under refrigeration (2°C–8°C) for up to 30 days.
⚠️ Common Preparation Mistakes to Avoid
Confusing PT-141 with Melanotan II (which causes skin tanning), shaking the vial causing foaming, and storing liquid solution at room temperature.
PT-141 Dosing FAQ
How much bac water do I add to 10mg PT-141?↓
Adding 2.0 mL of bac water to a 10 mg PT-141 vial creates a concentration of 5.0 mg/mL. A 1.75 mg dose equals 35 units on a U-100 syringe.
How many units is 1.0 mg PT-141 on a 10mg vial with 2mL water?↓
With 2.0 mL of water in a 10 mg vial (5 mg/mL), a 1.0 mg dose is 20 units (0.20 mL).
What is the half-life of PT-141?↓
PT-141 has an elimination half-life of approximately 2.7 hours following subcutaneous administration.
Does PT-141 cause skin tanning?↓
No. Unlike Melanotan II, PT-141 lacks the C-terminal amide required for significant MC1R melanocyte activation.
Can PT-141 be frozen after reconstitution?↓
No. Liquid peptide solutions must never be frozen. Store refrigerated at 2°C–8°C.