LA LABResearch Reference Document
Compound Guide
Melanotan II — Melanocortin Receptor Agonist
Quick Start
Not Approved — Mole Monitoring Required
Melanotan II (MT-II) is NOT FDA-approved and is illegal to sell for human use in the US, UK, and Australia. It is not approved in any major jurisdiction as a medical treatment. Case reports have linked MT-II use to melanoma and rapid changes in existing naevi (moles). All existing moles must be documented before starting any research protocol and monitored regularly. Discontinue immediately if any mole changes in size, colour, shape, or texture.
What It Is
Melanotan II is a synthetic cyclic analogue of alpha-melanocyte stimulating hormone (alpha-MSH), developed at the University of Arizona in the 1980s–1990s as a sunless tanning agent. It activates melanocortin receptors (MC1R, MC3R, MC4R, MC5R), producing skin tanning, sexual effects, and appetite suppression. It is not selective — it activates all melanocortin receptor subtypes simultaneously.
Research Dosing Protocol
Loading: 100–250 mcg/day → titrate to 250–500 mcg/day → 500–1,000 mcg/day (administered at bedtime to minimise nausea). Maintenance: 500–1,000 mcg 1–2× per week once desired effect is observed. Plasma half-life is approximately 1–2 hours — not "33 hours" (a commonly cited error that confuses plasma clearance with tissue/receptor effects).
Regulatory Status
Not approved in any major jurisdiction. Illegal to sell for human use in the US, UK, and Australia. No FDA IND filed. Not on WADA list. For research purposes only. Researchers should be aware of their jurisdiction's specific regulations regarding this compound.
Research Protocol
| Phase | Dose | Frequency | Duration | Notes |
|---|---|---|---|---|
| Titration start | 100–250 mcg | Once daily, bedtime | 1–2 weeks | Bedtime reduces nausea; start low to assess tolerance |
| Titration mid | 250–500 mcg | Once daily, bedtime | 1–2 weeks | Increase when lower dose is well tolerated |
| Target dose | 500–1,000 mcg | Once daily, bedtime | Until desired effect observed | Most protocols target effect within 4–8 weeks total |
| Maintenance | 500–1,000 mcg | 1–2× per week | Ongoing | Lower frequency once skin saturation observed |
Supplies & Reconstitution
Reconstitution Math — 10 mg Vial (3 mL BAC)
| Target Dose | Units (U-100) | Doses / Vial |
|---|---|---|
| 250 mcg | 7.5 units | 40 |
| 500 mcg | 15.0 units | 20 |
| 750 mcg | 22.5 units | 13.3 |
| 1000 mcg | 30.0 units | 10 |
Reconstitute the 10 mg vial with 3.0 mL bacteriostatic water (sold separately) → 3.33 mg/mL (3,333 mcg/mL). U-100 syringe = 100 units per mL. Swirl gently — do not shake. Refrigerate 2–8°C.
Reconstitution Steps
01
Warm the vial
Allow vial to reach room temperature from freezer before reconstitution.
02
Swab and draw
Alcohol swab both vial tops, air-dry. Draw 3.0 mL BAC water.
03
Inject along the wall
Let BAC water run slowly down the inside wall. Do not jet onto the powder.
04
Swirl gently
Swirl until clear and fully dissolved. Do not shake. Bedtime injection minimises nausea awareness.
05
Refrigerate
Store at 2–8°C for up to 30 days. Protect from light. Do not freeze after reconstitution.
Mechanism of Action & Receptor Profile
| Receptor | Location | Activation Effect |
|---|---|---|
| MC1R | Melanocytes in skin | Stimulates melanin production → skin darkening (tanning effect) |
| MC3R | Hypothalamus, brain limbic | Appetite suppression; sexual response contribution; energy balance |
| MC4R | Hypothalamus, PVN | Strong appetite suppression; sexual response; nausea (via area postrema) |
| MC5R | Exocrine glands, skin | Sebaceous gland activity; may contribute to oiliness during use |
MT-II activates all five melanocortin receptor subtypes. PT-141 (Bremelanotide) is more selective for MC3R/MC4R with far less MC1R activation — explaining PT-141's minimal tanning effect vs MT-II's strong tanning effect.
Melanoma Risk — Naevus Monitoring Required
Multiple case reports associate MT-II use with rapid changes in existing naevi and, in some cases, melanoma. MC1R activation stimulates melanocyte proliferation and melanin production — effects that can theoretically promote existing atypical melanocytes. Dermatological documentation of all existing moles before protocol start and regular monitoring are essential in any research context. Discontinue immediately if any mole changes appearance.
MT-II vs Related Melanocortin Compounds
| Compound | FDA Status | Tanning | Sexual Effect | Half-life |
|---|---|---|---|---|
| Melanotan II (MT-II) | Not approved | Strong (MC1R) | Yes (MC3R/MC4R) | ~1–2 h plasma |
| PT-141 (Bremelanotide / Vyleesi) | Approved (HSDD women) | Minimal | Yes — primary effect | ~2.7 h |
| Afamelanotide (Scenesse) | Approved (EPP) | Strong (MC1R selective) | Minimal | Implant releases over ~60 days |
Storage
| State | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilised (powder) | −20°C (freezer) | Up to 24 months | Protect from light; sensitive to moisture |
| Reconstituted (liquid) | 2–8°C (refrigerator) | Up to 30 days | Do not freeze after reconstitution; protect from light |
Disclaimer
This document is an educational research reference only. Melanotan II is not approved for human use in any major jurisdiction. Case reports link its use to melanoma. Mole monitoring is essential in any research protocol. Do not use alongside PT-141. By purchasing from LA LAB you confirm you are 18+ and that products are for research purposes only.
Side Effects & What People Report
Melanotan II has no approval anywhere and no completed safety trial. It has, however, been the subject of repeated public health warnings — which is unusual for a compound on this list and worth taking seriously.
| Reported | Detail |
|---|---|
| Nausea | Very common, especially on the first doses. The usual reason people start low. |
| Facial flushing | Common shortly after injection. |
| Spontaneous erections | A well-documented effect — PT-141 was developed from this observation. |
| Darkening of existing moles and freckles | Expected, and the core safety concern. Existing pigmented lesions darken and new ones can appear. |
| Appetite suppression | Frequently reported. |
| Tiredness after injection | Common; why it is often taken at night. |
This is the one on this list with genuine published harm reports
Health authorities in several countries have issued warnings about Melanotan II. Case reports in the dermatology literature describe new and changing melanocytic lesions, and at least one describes melanoma arising in a mole that changed during use. Causation is not proven — but a compound that deliberately drives pigment cells, used by people who then also seek sun exposure, deserves real caution rather than a shrug.
Who Should Avoid Melanotan II
| Situation | Why |
|---|---|
| Any history of melanoma or skin cancer | Avoid completely. |
| Many moles, atypical moles, or a family history of melanoma | Avoid. This is the highest-risk group for exactly the concern above. |
| Unwilling to have a skin check | If you use this, have a dermatologist map your moles first and review them. That is not optional advice. |
| Pregnancy or breastfeeding | Avoid. No data. |
| Under 18 | Avoid. |
| Known heart or blood-pressure conditions | Melanocortin receptors affect cardiovascular function; not studied. |
Frequently Asked Questions
Does it mean I can skip sunscreen?
No. Increased pigment is not the same as protection from UV damage, and the biggest documented risk with this compound is to your skin. Use sunscreen.
No. Increased pigment is not the same as protection from UV damage, and the biggest documented risk with this compound is to your skin. Use sunscreen.
Melanotan I or II?
Melanotan I (afamelanotide) is approved in some countries for a rare light-sensitivity disorder, under medical supervision. Melanotan II is the unapproved one, and is what is generally sold.
Melanotan I (afamelanotide) is approved in some countries for a rare light-sensitivity disorder, under medical supervision. Melanotan II is the unapproved one, and is what is generally sold.
Why does it cause erections?
It acts on melanocortin receptors in the brain. That side effect is the origin of PT-141, which was developed specifically for it.
It acts on melanocortin receptors in the brain. That side effect is the origin of PT-141, which was developed specifically for it.
How long does the tan last?
Users describe months rather than weeks, fading gradually.
Users describe months rather than weeks, fading gradually.
What about my moles?
They will likely darken. Get them mapped by a dermatologist before starting and reviewed afterwards. Any mole that changes shape or border needs looking at, not monitoring at home.
They will likely darken. Get them mapped by a dermatologist before starting and reviewed afterwards. Any mole that changes shape or border needs looking at, not monitoring at home.
Is the nausea avoidable?
Starting very low and building slowly is what most users do.
Starting very low and building slowly is what most users do.
Sources & Research
Langan EA, Nie Z, Rhodes LE. Melanotropic peptides: more than just ‘Barbie drugs’ and ‘sun-tan jabs’? Br J Dermatol 2010;163:451–5.
Cardones AR, Grichnik JM. α-Melanocyte-stimulating hormone-induced eruptive nevi. Arch Dermatol 2009;145:441–4.
Ong S, Bowling J. Melanotan-associated melanoma in situ. Australas J Dermatol 2012;53:301–2.
Regulatory status — not approved anywhere. Multiple national health authorities have issued public warnings against its use.
Educational reference only
This document is a research reference, not medical advice and not a treatment plan. Melanotan II is unapproved everywhere and has been the subject of public health warnings and case reports of changing pigmented lesions. Dose decisions belong to you and your prescriber. Independent certificates of analysis for every LA LAB batch are published under Research → Lab Results, with the Janoshik task number and verification key so you can check them yourself.