Melanotan II & PT-141 Stack Dosage Protocol
Melanocortin agonists — Melanotan II (tanning) + PT-141/bremelanotide (libido). Two separate vials; combination not clinically validated.
Mix & measure Melanotan II + PT-141 · 20 mg
Pre-filled with this protocol’s recommended BAC water and documented starting dose — edit any field to run your own numbers.
Reconstitution math only — not dosing advice. U-100 syringe: 100 units = 1 mL. Full reconstitution guide → · Advanced calculator →
Quickstart Highlights
This page pairs two melanocortin-receptor agonists kept in separate vials: Melanotan II, a non-selective MC1R–MC5R agonist used for tanning, and PT-141 (bremelanotide), a central MC4R agonist for sexual desire that is in fact derived from Melanotan II[1]. PT-141 is FDA-approved only as the finished drug Vyleesi for premenopausal women with HSDD; Melanotan II is approved nowhere and carries documented serious safety signals. The “tanning + libido” combination is not clinically validated — presented for research and educational use only.
Reconstitute 10 mg with 3 mL bacteriostatic water → 3.33 mg/mL. Tanning cycle: 250–500 mcg, 2×/week over a gradual 4-week build.
Reconstitute 10 mg with 1 mL bacteriostatic water → 10 mg/mL. On-demand: 1.75 mg (female HSDD) at least 45 min before activity; max 1 / 24 h, ≤ 8 / month.
Each peptide is mixed and drawn in its own vial and syringe. Never combine them in one syringe; inject at separate sites.
Keep dry vials cold until use; once reconstituted, store at 2–8 °C (refrigerator), protected from light, and do not freeze.
Important: Start with the Prep & Injection Guide — it covers the preparation and safety basics every protocol on this site assumes.
Dosing & Reconstitution Guide
Two separate vials, dosed independently — reconstitute and measure each peptide on its own
Melanotan II (10 mg vial) — Gradual Tanning Build (3 mL = 3.33 mg/mL)
Reconstitute: Add 3 mL bacteriostatic water to the 10 mg vial → 3.33 mg/mL. On a U-100 syringe, 1 unit ≈ 33 mcg.
Weeks 1–2: 250 mcg (0.25 mg) per injection → ~7.5 units (0.075 mL), 2× per week.
Weeks 3–4: 500 mcg (0.5 mg) per injection → ~15 units (0.15 mL), 2× per week.
Note: Early doses are under 10 units — a 30-unit insulin syringe improves accuracy. Build gradually over the 4-week cycle to limit nausea and flushing.
PT-141 (10 mg vial) — On-Demand (1 mL = 10 mg/mL)
Reconstitute: Add 1 mL bacteriostatic water to the 10 mg vial → 10 mg/mL. On a U-100 syringe, 1 unit = 0.1 mg (100 mcg).
Female HSDD (Vyleesi-equivalent): 1.75 mg → ~18 units (0.18 mL), as needed at least 45 min before activity[1].
Male ED (off-label, not FDA-approved): 1–2 mg → 10–20 units (0.10–0.20 mL), 30–60 min before activity.
Limits: Maximum one dose per 24 hours and no more than 8 per month. Alternatively, some references split into 1 mg (10 units) twice weekly.
Reconstitution steps: Draw the bacteriostatic water into a sterile syringe and inject it slowly against the vial wall — do not shake. Swirl gently until dissolved, label each vial with the date, then refrigerate at 2–8 °C, protected from light.
Supplies Needed
Quantities below cover a 4-week Melanotan II tanning cycle plus on-demand PT-141 dosing. Each peptide is kept and injected separately.
At 2×/week with a gradual 250–500 mcg build, one 10 mg vial covers roughly a full 4-week cycle.
- 4-week cycle: ~1–2 vials
At ~1.75 mg per on-demand dose, one 10 mg vial covers roughly 5–8 doses (the monthly cap).
- Per month: ~1 vial (≤ 8 doses)
A 30-unit syringe improves accuracy for the small Melanotan II doses; use a fresh syringe per injection.
- Melanotan II: ~8 / cycle
- PT-141: 1 per dose
3 mL per Melanotan II vial and 1 mL per PT-141 vial, plus two alcohol swabs (stopper + site) each injection.
- Bac water: 1–2 bottles
- Alcohol swabs: 1 box
Protocol Overview
A concise summary of the two-vial stack: a fixed 4-week Melanotan II tanning cycle plus on-demand PT-141 for libido.
- ▪Melanotan II: 250–500 mcg per injection, 2× weekly across a gradual 4-week build (tanning).
- ▪PT-141: 1.75 mg per injection, as needed at least 45 min before activity — max 1 / 24 h, ≤ 8 / month (libido).
- ▪Cycle length: Melanotan II runs 4 weeks; PT-141 is flexible and on-demand only.
- ▪Reconstitution: Melanotan II with 3 mL (3.33 mg/mL); PT-141 with 1 mL (10 mg/mL).
- ▪Validation: The tanning + libido combination is not clinically validated; the vials are used separately, never mixed.
Stack Administration
Because each peptide has its own schedule, concentration and syringe, administer them independently.
- ▪Separate syringes: Never combine Melanotan II and PT-141 in one syringe or vial; draw and inject each on its own.
- ▪Melanotan II timing: Inject on two consistent days each week (for example Monday and Thursday) for the 4-week cycle.
- ▪PT-141 timing: Use only before anticipated sexual activity — not on a fixed daily schedule.
- ▪Same-day use: If both fall on one day, use separate sites and separate syringes; do not stack them in a single shot.
- ▪Logs: Track each peptide’s dose, date and effects separately to keep the protocol consistent.
Storage Instructions
Correct storage preserves the stability of both peptides.
- ▪Lyophilized: Keep both dry vials cold and dark until reconstitution, limiting moisture exposure.
- ▪Reconstituted: Store both solutions at 2–8 °C (refrigerator), protected from light, and do not freeze the mixed solution.
- ▪Handling: Let chilled vials reach room temperature before drawing, and keep solutions clear of heat and direct light.
- ▪Freeze–thaw: Avoid repeated freeze–thaw cycles of either reconstituted solution.
Important Notes
Safety and regulatory points that apply to this two-peptide stack.
- ▪Never mix the vials: Use a fresh sterile U-100 syringe for each peptide and each injection; dispose of it in a sharps container.
- ▪Melanotan II safety signals: Documented serious risks include melanoma and changes to moles, priapism, rhabdomyolysis, renal infarction and posterior reversible encephalopathy (PRES). It is approved nowhere and has drawn regulatory warning letters.
- ▪PT-141 cautions: Can cause transient blood-pressure increase, nausea and flushing; observe the 1 / 24 h and ≤ 8 / month limits[4].
- ▪Monitoring: Watch for nausea, facial flushing and blood-pressure changes, and have a dermatologist check any pigment or mole changes during Melanotan II use.
- ▪Regulatory note: Only the finished drug Vyleesi (PT-141) is FDA-approved — for premenopausal women with HSDD. Research-grade PT-141, male/off-label use, and all Melanotan II use are not covered. Melanotan II is also caught by WADA category S0.
How This Works
Both peptides act on the melanocortin receptor family, and PT-141 (bremelanotide) is in fact a metabolite-derived analogue of Melanotan II[1]. That shared origin is why they appear together — but they target different receptors and outcomes.
Melanotan II is a non-selective MC1R–MC5R agonist. Activation of MC1R in skin drives melanin synthesis (tanning), while central MC3R/MC4R activity is linked to its libido and appetite effects[5].
PT-141 (bremelanotide) is a more selective central MC4R agonist that acts in the brain to increase sexual desire and arousal, rather than acting on the genital vasculature like PDE5 inhibitors[1][3].
Approval status, plainly: PT-141 as the finished drug Vyleesi is FDA-approved (2019), but only for premenopausal women with HSDD. Research-grade PT-141 and any male or off-label use are not covered by that approval. Melanotan II is not approved anywhere — it is a research chemical with FDA warning letters and documented serious safety signals (melanoma, priapism, rhabdomyolysis, renal infarction, PRES).
The popular “tanning + libido synergy” framing for combining these peptides is not clinically validated. This page is for research and educational purposes only.
Lifestyle Factors
Habits that support tolerability and reduce risk alongside the stack.
- ▪Sun caution: Melanotan II does not replace sun protection — continue using sunscreen and avoid the assumption that a deeper tan means UV safety.
- ▪Skin checks: Photograph and monitor moles; see a dermatologist for any new, changing or asymmetric lesions.
- ▪Hydration & nutrition: Stay well hydrated and eat regularly, since nausea is a common early effect of both peptides.
- ▪Blood pressure: If you are sensitive to blood-pressure changes, check it before and after PT-141 and avoid alcohol around dosing.
Potential Benefits & Side Effects
What the literature describes for each peptide. Only Vyleesi (PT-141) for female HSDD has FDA-level efficacy data; Melanotan II is unapproved.
Reported Effects
- ▪Melanotan II — tanning: Increased melanin and a deeper tan with less sun exposure, via MC1R activation.
- ▪PT-141 — libido: Increased sexual desire and arousal; for female HSDD this is supported by Vyleesi trial data[3].
- ▪Not validated together: No trial supports combining the two for a tanning + libido “synergy.”
Side Effects & Risks
- ▪Common: Nausea, facial flushing and headache with either peptide, often strongest early on.
- ▪Melanotan II — serious: Melanoma and mole changes, priapism, rhabdomyolysis, renal infarction and PRES have been reported.
- ▪PT-141: Transient blood-pressure increase and, rarely, focal hyperpigmentation with repeated use[4].
- ▪Sport restriction: Melanotan II is caught by WADA category S0 (non-approved substances).
Injection Technique
General subcutaneous technique, applied separately to each peptide, following established best-practice guidance[6].
Pre-Injection Preparation
- ▪Wash your hands well with soap and water.
- ▪Confirm you have the correct vial — Melanotan II (3.33 mg/mL) or PT-141 (10 mg/mL) — before drawing.
- ▪Wipe the vial stopper and the chosen site (abdomen, thigh or upper arm) with separate alcohol swabs and let them air-dry.
- ▪Draw the intended dose into the right syringe, then check for air bubbles and push any out.
Injection Procedure
- ▪Pinch a skinfold at the chosen site between thumb and forefinger.
- ▪Insert the needle at a 45–90-degree angle (use 45 degrees if the fat layer is thin)[6].
- ▪Skip aspiration for subcutaneous shots — it isn’t needed.
- ▪Press the plunger slowly and steadily until it’s fully down.
- ▪Wait 5–10 seconds, then pull the needle straight out to prevent leakage.
Post-Injection Care
- ▪Drop the used syringe straight into a puncture-proof sharps container — never recap a needle.
- ▪Return each reconstituted vial to the fridge right away.
- ▪Rotate sites between injections to prevent irritation and lipohypertrophy.
- ▪Watch each site for excess redness, swelling or signs of infection.
Recommended Source
For high-purity research peptides, we point researchers to Prime Lab Peptides, including PT-141 (10 mg).
Why Prime Lab Peptides?
- ▪Top-rated on Trustpilot: Independently reviewed as the highest-rated peptide lab on Trustpilot — making it the best current source in the USA.
- ▪Third-party tested: Every batch ships with a Certificate of Analysis (COA) confirming purity and composition.
- ▪Consistent quality: ISO-aligned manufacturing and handling keep product integrity reliable batch to batch.
- ▪Cold-chain integrity: Temperature-controlled shipping and storage across the whole fulfilment chain.
- ▪Research-grade purity: Fit for educational and research use that demands high-quality peptides.
Note: Product availability and specifications subject to change. Verify current product details on supplier website.
References
- 1
FDABremelanotide (Vyleesi) prescribing information — dosing, indication (premenopausal HSDD), and use limitations.
- 2
NCBI Bookshelf (LiverTox)Bremelanotide: mechanism as a melanocortin-4 receptor agonist, clinical use, and safety profile.
- 3
PMCBremelanotide for female hypoactive sexual desire disorder — phase-3 clinical trial review.
- 4
Mayo ClinicBremelanotide (subcutaneous route): side effects, precautions, and transient blood-pressure effects.
- 5
PubMedEvaluation of Melanotan-II: pilot phase-I study and melanocortin receptor pharmacology (MC1R–MC5R).
- 6
TGA AustraliaSafety alert — the serious health risks of unapproved Melanotan tanning products.
- 7
Prime Lab PeptidesPT-141 (10 mg) product page — purity specifications and certificates of analysis.
- 8
How to reconstitute Melanotan II + PT-141
- 1Wipe the vial stopper and your bacteriostatic-water vial with an alcohol swab.
- 2Draw your chosen amount of bacteriostatic water and inject it slowly down the inner wall of the Melanotan II + PT-141 vial.
- 3Let it rest, then gently swirl until fully dissolved — do not shake.
- 4Refrigerate the reconstituted vial and draw each dose with a U-100 insulin syringe.
Melanotan II + PT-141 — frequently asked questions
How do I reconstitute a 20 mg vial of Melanotan II + PT-141?
Wipe the stopper with an alcohol swab, then inject your bacteriostatic water slowly down the inside wall of the vial. Let it sit and gently swirl until dissolved — never shake. Store the mixed vial in the refrigerator and draw doses with an insulin syringe. Use the calculator above to turn any dose into syringe units.
How much bacteriostatic water should I add to Melanotan II + PT-141?
There is no single correct amount — more water simply spreads the same 20 mg of peptide across a larger volume, which makes small doses easier to measure accurately. 1 to 3 mL per vial is typical. Enter your chosen volume in the calculator above to see the resulting concentration and syringe units.
What do the "units" on an insulin syringe mean?
On a U-100 insulin syringe, 100 units equal 1 mL, so 1 unit equals 0.01 mL. The calculator above converts your draw volume into these units automatically so you can measure without doing the math by hand.
How should I store Melanotan II + PT-141 after mixing?
Keep the reconstituted vial refrigerated at roughly 2 to 8 degrees Celsius, away from light, and avoid freezing it. Reconstituted research peptides are generally used within a few weeks. Always follow the specific guidance supplied with your product.
How many doses does a 20 mg vial of Melanotan II + PT-141 provide?
Divide the vial strength of 20 mg by the amount you use per injection. The calculator above reports this as "doses per vial" the moment you enter a dose.
Is Melanotan II + PT-141 approved for human use?
No. Melanotan II + PT-141 is sold strictly for laboratory and research purposes and is not approved by the FDA or other regulators for human use. Everything on this page is research information, not medical advice — consult a licensed healthcare professional before any use.
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