Melanotan II 10mg · α-MSH Analog (MT-II) · 98.6% Purity

What is Melanotan II?

Melanotan II (MT-II) is a synthetic non-selective melanocortin receptor agonist. By activating MC1R it stimulates melanin synthesis (the tanning effect); by activating MC3R and MC4R it modulates central sexual arousal pathways — the basis for libido research and for the FDA-approved spinoff PT-141.

What is Melanotan II used for?

Two dominant research applications: UV-independent pigmentation (skin tanning) and central libido response. Both effects are dose-dependent. Researchers comparing MT-II vs. its more selective cousin PT-141 find MT-II offers stronger libido response but with broader off-target effects (nausea, appetite suppression, freckle darkening).

How does it work?

Non-selective melanocortin receptor agonist (MC1R, MC3R, MC4R); stimulates melanogenesis (tanning) and central libido pathways. Read our complete research hub for the full literature review, or jump to our best peptides for libido article for comparator molecules.

Why this listing?

Helix Peptides' MT-II batch MT2-2604-F tested 98.6% purity (HPLC). Because MT-II affects existing melanocytes, expect existing moles/freckles to darken — perform a skin check before any tanning research protocol.

How Peptide.best sources and verifies Melanotan II

Every Melanotan II listing on Peptide.best comes from a verified vendor that has passed our onboarding audit — GMP-licensed manufacturing facility, documented chain of custody, third-party Janoshik Analytical testing on every batch, and a published Certificate of Analysis. Helix Peptides (the seller on this listing) currently maintains a 4.7-star average across all their products. Compare the five live offers on the right side of this page — Peptide.best forces vendors to compete on price and purity for the same SKU, so you always see the best current deal at the top, with the COA-verified purity, shipping speed, and seller rating side-by-side. Looking for alternatives in the same libido space? PT-141 and the other peptides listed under our Libido category are the most commonly compared alternatives.

Commonly stacked with

PT-141 · GHK-Cu · Ipamorelin · CJC-1295. See the peptide stacks page for full protocol writeups.

Compliance notice

Melanotan II has not been evaluated by the FDA for any indication. All statements on this page are based on published research and are not medical claims. Some products may be sold for research purposes only as marked. Consult a licensed healthcare provider before use. See our full disclaimer.

Research literature

Melanotan II has been the subject of growing peer-reviewed and preclinical research across the libido domain. The current PubMed index returns several hundred citations spanning mechanism, dose-response, and adverse-event reporting.

Key references commonly cited in Melanotan II research:

• Mechanism papers covering non-selective melanocortin receptor agonist (mc1r, mc3r, mc4r); stimulates melanogenesis (tanning) and central libido pathways.
• Dose-response work in rodent models (most studied species)
• Comparator-molecule trials vs. PT-141 and other peptides in the same class
• Safety / pharmacovigilance datasets where available

For a full reference list, see the Peptide.best Research Hub or the dedicated Libido pillar article.

Standard research dosing

Loading phase: 0.25–0.5 mg/day subcutaneous until desired pigment level reached (typically 1–3 weeks). Maintenance: 0.5–1 mg, 1–2x per week. For libido-only research: single 1 mg dose 1–2 hours pre-activity.

Reconstitution

This product ships as lyophilized powder. Reconstitute with Bacteriostatic water (2mL) for stable refrigerated storage. Once reconstituted, use within 30 days; keep at 2–8°C.

Protocol notes

For full protocols and stacking guidance, see our peptide dosing guides. Always start at the low end of the published range and titrate based on individual response. Half-life (~33 hours (long systemic)) determines dosing frequency.

Reported side effects

Most-common: nausea (especially first 3 doses), facial flushing, appetite suppression, spontaneous erection in male subjects. Darkening of moles is universal — annual dermatology screening is recommended.

Contraindications

Do not use during pregnancy or lactation. Do not combine with other peptides without reviewing pharmacology. Consult a licensed healthcare provider before beginning any peptide research protocol. Discontinue immediately if any adverse reaction occurs and contact your provider.

Drug interactions

Limited interaction data exists for most research peptides. Be especially cautious when combining with prescription medications affecting the same physiological pathway as Melanotan II (libido pathway).

Certificate of Analysis

Every batch of Melanotan II sold on Peptide.best ships with a third-party Certificate of Analysis (COA) from Janoshik Analytical — the most-cited independent peptide testing lab in the research community.

Current batch testing summary

• Batch ID: MT2-2604-F
• Test date: 04/14/2026
• Peptide content (HPLC): 98.6%
• Mass-spec identity: Confirmed (target mass match)
• Endotoxin (LAL): Below detection limit
• Residual solvents: Within USP <467> limits

Download full COA PDF

For our overall testing process and chain-of-custody details, see Trust & Safety.

Q: Is Melanotan II legal to purchase?

A: Melanotan II is sold on Peptide.best for research purposes where applicable. Legal status varies by jurisdiction. See our disclaimer for full details.

Q: How long until I see effects?

A: Timing depends on protocol, dose, and individual response. Most users report observable changes within 2–6 weeks of consistent dosing per the standard research protocols. See the Dosing & Protocol tab.

Q: Can I stack Melanotan II with other peptides?

A: Yes — see commonly stacked peptides in the Overview tab, or browse our peptide stacks page for full protocol writeups.

Q: Why is the price lower than pharmacy retail or other research sites?

A: Peptide.best aggregates verified vendors and forces them to compete in a single checkout. Vendors save on customer-acquisition cost; the savings pass to you. Every batch is still 3rd-party COA tested.

About Helix Peptides

Helix Peptides is one of the six verified vendor partners on Peptide.best. They maintain a 4.7-star average rating across all products and submit every batch to third-party HPLC analysis before it ships.

All Helix Peptides products on Peptide.best ship from a GMP-licensed contract manufacturing facility and are tested by Janoshik Analytical. Cold-chain shipping is included on temperature-sensitive products.