Editor's Note

Both Melanotan II and PT-141 (Bremelanotide) are melanocortin receptor agonists. PT-141 is the FDA-approved derivative specifically targeting sexual function. Melanotan II has broader receptor activity including tanning effects.

Quick Verdict

Melanotan II is a melanocortin agonist primarily researched for tanning, libido enhancement, while PT-141 is a melanocortin agonist studied for sexual arousal, libido. A key distinction: PT-141 has FDA approval status.

Side-by-Side Analysis

DimensionMelanotan IIPT-141
CategoryMelanocortin AgonistMelanocortin Agonist
MechanismMC4R activation.Central melanocortin pathway.
Half-Life~1 hours~2.7 hours
RouteSubQSubQ
Typical Dose250–250 mcg1500–1500 mcg
Frequency7x/wk2x/wk
Evidence LevelModerateVery Strong
Indexed Studies20+ indexed19+ indexed
FDA StatusResearch OnlyApproved
Lowest Price$40.00 / 10mg via Ascension Peptides$45.00 / 10mg via Ascension Peptides
Per-mg Cost$4.00/mg$4.50/mg

Mechanism of Action Comparison

How Melanotan II Works

Melanotan II Melanotan II is a synthetic melanocortin analog studied for stimulating skin tanning, suppressing appetite, and increasing sexual arousal, though it carries significant safety concerns.

MC4R activation. Non-selectively activates melanocortin receptors to stimulate melanin production, suppress appetite, and increase sexual arousal.

How PT-141 Works

PT-141 PT-141 (Bremelanotide) is an FDA-approved melanocortin agonist prescribed as Vyleesi for hypoactive sexual desire disorder in premenopausal women, also studied for male erectile dysfunction.

Central melanocortin pathway. Activates MC4R in the CNS to stimulate sexual desire through brain pathways rather than vascular effects.

Key Mechanistic Difference

Both Melanotan II and PT-141 belong to the Melanocortin Agonist class, but differ in their specific molecular targets and pharmacokinetic profiles.

Research Evidence

Melanotan II

20 studies
View all Melanotan II research

PT-141

19 studies
View all PT-141 research

Vendor Pricing

· Affiliate links · Prices verified 2026

Melanotan II

2 vendors
Ascension PeptidesBest Price Best Value
10mg vial · $4.00/mg
$40.00Buy
Bio Longevity LabsTriple-Tested
10mg vial · $5.60/mg
$55.97Buy

PT-141

2 vendors
Ascension Peptides Best Value
10mg vial · $4.50/mg
$45.00Buy
Bio Longevity LabsTriple-Tested
5mg vial · $9.59/mg
$47.97Buy

Affiliate disclosure: PeptiDex may earn a commission from purchases via vendor links at no extra cost to you. See our methodology.

Frequently Asked Questions

Can I take Melanotan II and PT-141 together?

Use caution. Melanotan II and PT-141 have overlapping mechanisms that may require careful dosing adjustment when used concurrently. Consult published research protocols before combining.

Which has more research evidence — Melanotan II or PT-141?

Melanotan II has 20 indexed studies (highest evidence: Moderate). PT-141 has 19 indexed studies (highest evidence: Very Strong). Melanotan II has a more extensive research base.

What is the price difference between Melanotan II and PT-141?

At current verified vendor prices, Melanotan II starts at $4.00/mg while PT-141 starts at $4.50/mg. Prices vary by vendor and vial size — see the full vendor comparison below.

Is Melanotan II or PT-141 FDA-approved?

PT-141 has FDA approval (or is derived from an FDA-approved compound). Melanotan II is a research compound without FDA approval for human use. FDA status reflects regulatory evaluation — not necessarily superiority for all research applications.

Related Comparisons

Research Use Only — Not Medical Advice

This comparison is provided for educational and research purposes only. It does not constitute medical, prescribing, or treatment advice. Clinical data cited here is sourced from published peer-reviewed trials and FDA labels. Consult a qualified healthcare professional before making any decisions about medications or research compounds. PeptiDex is an informational resource and does not sell pharmaceutical products.