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Peptide Library / Sexual Health / Hormone

PT-141 (Bremelanotide)

Melanocortin MC4R agonist

PT-141 (Bremelanotide) Research Protocol

Complete Research Guide 4 min read1 peer-reviewed references

Quickstart Overview

PT-141 (bremelanotide) is a melanocortin-receptor agonist derived from Melanotan II and approved as a treatment for hypoactive sexual desire disorder in premenopausal women. Unlike vascular ED drugs it acts centrally in the brain to increase sexual desire and arousal.

Reconstitution
Add 2.0 mL bacteriostatic water to a 10 mg vial → 5 mg/mL
Literature Range
1–2 mg per administration
Measuring Reference
At 5 mg/mL: 1 mg = 0.2 mL = 20 units
Frequency
As needed
Route (studies)
Subcutaneous
Onset
~45 min

Scientific Data

Molecular Formula
—
Molecular Weight
1025.2 Da
Sequence
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH
Sequence Length
31
CAS
Research compound
Peptide Family
Melanocortin agonist
Half-life
Refer to published literature
Solubility
Bacteriostatic water, sterile saline
Storage
Lyophilized: -20°C. Reconstituted: 2–8°C, use within 2–4 weeks.
Appearance
White lyophilized powder
Standard: 10 mg vial · 2 mL diluent

Dosing & Reconstitution Guide

Interactive Reconstitution
Adjust vial size, diluent and target dose. Results update live.
Full Precision Calculator →
Concentration
5.00 mg/mL
Draw Volume
0.200 mL
Syringe Units
20.0 U
Doses / Vial
10

Units assume a U-100 insulin syringe (100 units = 1 mL). On-demand use ~45 min before activity; start at 1 mg (nausea is common).

Frequency: As needed

Reconstitution Steps

  1. 1Allow the lyophilized vial and bacteriostatic water to reach room temperature (~15 min).
  2. 2Swab both vial stoppers with a fresh 70% isopropyl alcohol pad and let them dry.
  3. 3Draw 2.0 mL of bacteriostatic water into a mixing syringe.
  4. 4Insert at an angle and let the water run slowly down the glass wall — never directly onto the powder.
  5. 5Gently swirl (do not shake) until the solution is completely clear.
  6. 6Label with date and concentration (mg/mL) and refrigerate at 2–8 °C immediately.

Supplies Needed

Planning example for a 4-week protocol at approximately 1000 mcg per day.

Peptide (10 mg vials)
Estimate vials from total mass: 1000 mcg/day × 28 days.
Bacteriostatic Water
One 10–30 mL vial typically covers a full cycle.
Insulin Syringes (U-100)
One per administration (29–31 G, 0.3–0.5 mL).
Alcohol Swabs
Two per administration (vial + site).
Sharps Container
Required for safe disposal.

Protocol Overview

Goal
Model central (MC4R) sexual-arousal pathways.
Schedule
On-demand, ~45 min pre-activity.
Dose Range
1–2 mg per use.

Dosing Protocol

Standard
1–2 mg ~45 min before activity
Frequency
As needed, not daily
Max
Limit frequency (≤ a few times/week)
Cycle Length
On-demand use
Timing
~45 minutes before anticipated activity
Route
Subcutaneous

Storage Instructions

Lyophilized
−20 °C long term (18–24 months); stable at room temperature for short transit.
Reconstituted
2–8 °C refrigerated; use within 4 weeks.
Light
Protect from direct light; keep in the original carton.
Freeze/Thaw
Avoid repeat freeze–thaw cycles after reconstitution.

Important Notes

  • Start at 1 mg — nausea is common initially.
  • On-demand compound; do not dose daily.

How This Works

PT-141 activates melanocortin receptors — principally MC4R in the hypothalamus — to increase sexual desire and arousal through central nervous-system pathways rather than the vascular (nitric-oxide/PDE5) mechanism of ED drugs. Because it works upstream in the brain, it can be effective where vascular agents are not, in both men and women. It was refined from Melanotan II to focus on MC4R while minimising pigmentation effects.

Potential Benefits & Side Effects

Reported in research
  • Centrally-mediated increase in sexual desire and arousal
  • Effective in both men and women
  • Works via a different pathway than PDE5 inhibitors
  • Approved (as bremelanotide) for HSDD in women
Possible considerations
  • Nausea (common, especially first doses)
  • Flushing and headache
  • Transient blood-pressure increase
  • Injection-site reactions
  • Mild skin darkening with repeated use

Lifestyle Factors

  • Adequate hydration and 7–9 h of sleep are standard controls in most research protocols.
  • Consistent dose timing improves the reliability of any self-tracked endpoints.
  • Maintain a clean, sterile workflow for every draw to avoid contamination.

Injection Technique

  1. 1Wash hands, then prep the vial top and the target site with separate alcohol swabs.
  2. 2Pinch a subcutaneous skin fold (abdomen, ~2 inches from the navel) and insert at 45–90°.
  3. 3Depress the plunger slowly over 3–5 seconds, hold 5 seconds, then withdraw.
  4. 4Rotate sites each administration and dispose of the syringe in a sharps container.

Frequently Asked Questions

Third-party HPLC testing

CG Labz Verified Batches

No published batches yet.

Research Disclaimer

All compounds are supplied strictly for laboratory research. Dosing figures below summarize ranges reported in published preclinical and clinical literature for reference purposes only. CG Labz does not provide medical advice or individualized dosing recommendations.

Peer-reviewed literature

References

  1. [1] Journal of Sexual Medicine
    Clayton A.H. et al. Bremelanotide for HSDD (RECONNECT trials).
    View Source