Melanotan-II Quick Start
Melanotan-II (MT-II) is a synthetic cyclic analog of alpha-melanocyte-stimulating hormone (α-MSH). It is a non-selective melanocortin-receptor agonist, acting at MC1R (linked to skin pigmentation) and MC4R (linked to sexual response and appetite). It is studied in pigmentation, photoprotection, and sexual-function research models.
This guide is an educational research reference. It does not diagnose, treat, or prescribe, and is not medical advice. Consult a licensed clinician before considering any compound.
Melanotan-II Dosing Protocols
The injectable (subcutaneous) and nasal-spray formats are documented as two separate protocols. Community-derived planning typically uses a low loading phase, then a smaller, less frequent maintenance phase once the target response is reached. These are research-planning references, not personal dosing recommendations.
Injection — Subcutaneous
| Phase | Per dose | Frequency |
|---|---|---|
| Loading | 250 mcg | Once daily |
| Maintenance | 500 mcg | 2–3× weekly |
Nasal Spray
| Phase | Per dose | # of sprays | Frequency |
|---|---|---|---|
| Loading | 300 mcg | 3 sprays | Once daily |
| Maintenance | 500 mcg | 5 sprays | 2–3× weekly |
Melanotan-II Reconstitution Guide
MT-II ships as a lyophilized powder. The BAC water volume sets the concentration and draw volume for the injectable vial. Nasal sprays ship pre-mixed and ready to use.
Injection
| BAC | Conc. | 250 mcg |
|---|---|---|
| 2 mL | 5,000 mcg/mL | 0.05 mL · 5 u |
| 1 mL | 10,000 mcg/mL | 0.025 mL · 2.5 u |
2 mL is the default; units are U-100 syringe units.
Reconstitution steps
- Inspect the vial. Confirm label and intact powder.
- Wipe the stoppers. Alcohol swab on both vials.
- Draw BAC water. 2 mL into the injectable vial.
- Inject down the wall. Release water slowly down the inside wall, not onto the powder.
- Swirl, do not shake. Roll gently until clear.
- Refrigerate. Store at 2–8 °C; do not freeze.
How to use the nasal spray
- Prime first use. Pump 2–3 sprays into a tissue until a fine, even mist appears.
- Position. Tilt the head slightly forward; insert the tip just inside one nostril, aimed slightly outward toward the ear — not at the septum.
- Spray and breathe. Press once while breathing in gently; do not sniff hard, which sends the solution down the throat instead of onto the mucosa.
- Alternate nostrils. For multi-spray doses, switch nostrils each spray to spread absorption and limit irritation.
- Count per the protocol. Use the sprays-per-dose shown above; if a dose isn't a whole number, round up.
- Between uses. Wipe the tip, recap, and refrigerate.
How Melanotan-II Works
MT-II mimics α-MSH and activates melanocortin receptors. At MC1R on melanocytes it stimulates melanogenesis (eumelanin production), the basis for pigmentation research. At MC4R in the central nervous system it influences sexual arousal and appetite — the same MC4R activity underlies the related approved fragment bremelanotide (PT-141).
MC1R → pigmentation
Stimulates melanin synthesis in melanocytes in pigmentation models.
MC4R → arousal/appetite
Central melanocortin activity linked to sexual response and reduced appetite.
Non-selective
Unlike PT-141, MT-II is not MC4R-selective, so it drives both pigmentation and central effects.
Open question
Long-term human safety, especially around melanocytic lesions, is not established.
Who Should Avoid Melanotan-II
Atypical moles / melanoma history
MT-II increases melanocyte activity and can darken moles; a personal/family history of melanoma or many atypical nevi is a key caution.
Pregnancy & lactation
No human reproductive safety data.
Cardiovascular concerns
Melanocortin activity can affect blood pressure; review with a clinician.
Unmonitored skin changes
New or changing pigmented lesions warrant dermatologic evaluation before continuing.
Melanotan-II Side Effects & Safety
Nausea & flushing
The most common short-term effects, typically worse early and at higher single doses.
Pigment changes
Darkening of moles, freckles, and new pigmented spots are commonly reported; dermatologic monitoring is prudent.
Spontaneous erections
A frequently reported MC4R-mediated effect in male users.
Appetite suppression
Reduced appetite is commonly reported.
Timeline & What to Monitor
| Timeframe | Commonly tracked | Notes |
|---|---|---|
| Days 1–3 | Nausea, flushing, injection-site response | Early-dose tolerability is most prominent here. |
| Weeks 1–3 | Pigmentation response | Pigment changes build gradually; this drives the loading→maintenance shift. |
| Ongoing | Moles and pigmented lesions | Track any new or changing lesion; seek dermatologic review. |
Research Evidence Context
Pigmentation
Early clinical and preclinical work explored melanotan peptides for tanning and photoprotection research.
Sexual function
MC4R activity informed development of the approved related fragment bremelanotide (PT-141).
Safety signals
Case reports describe changing moles and melanoma concerns with unregulated MT-II use.
Open question
MT-II itself is not an approved drug and lacks long-term controlled safety data.
Storage & Handling
| State | Storage | Notes |
|---|---|---|
| Lyophilized (powder) | −20 °C long-term; fridge short-term | More stable than reconstituted solution. |
| Reconstituted (liquid) | 2–8 °C | Use within ~3–4 weeks; do not freeze. |
| Appearance | Clear, colorless | Discard cloudy or particulate solutions. |
Mistakes & Troubleshooting
- Strong nausea/flushing. Often dose-related; research protocols typically start low and titrate slowly.
- Wrong BAC volume. Recalculate concentration; injection assumes 2 mL, spray assumes 10 mL.
- Missed dose. Skip and continue at the next scheduled time; do not double-dose.
- New or changing mole. Stop and seek dermatologic evaluation.
- Left out overnight. Treat reconstituted solution as compromised and discard.
Melanotan-II vs PT-141
| Feature | Melanotan-II | PT-141 (Bremelanotide) |
|---|---|---|
| Selectivity | Non-selective (MC1R + MC4R) | MC4R-selective |
| Main research focus | Pigmentation + sexual response | Sexual response |
Monitoring
There is no peptide-specific lab for MT-II. The most relevant monitoring is dermatologic — periodic skin/mole checks — plus blood-pressure awareness given melanocortin vascular effects.
Frequently Asked Questions
What is Melanotan-II?
A synthetic α-MSH analog and non-selective melanocortin agonist studied in pigmentation and sexual-function research.
How is the injection dosed vs the nasal spray?
Separate protocols. Injection commonly references 250 mcg daily loading then 500 mcg 2–3× weekly. The spray delivers 100 mcg per spray, so loading is 3 sprays and maintenance is 5 sprays.
How is MT-II reconstituted?
For injection, 10 mg in 2 mL BAC water gives 5,000 mcg/mL, so 250 mcg = 0.05 mL = 5 units. The spray ships pre-mixed and delivers 100 mcg per spray.
Why does MT-II cause nausea and darker moles?
MC4R activity drives nausea/flushing (worse early), and MC1R activity increases melanocyte activity, which can darken existing moles and create new pigmented spots. Changing lesions warrant dermatologic review.
Is this page medical advice?
No. It is an educational research reference and does not diagnose, treat, or prescribe. Consult a licensed clinician before considering any compound.
References
- Dorr RT, et al. Evaluation of melanotan-II, a superpotent melanotropic peptide, in humans. Life Sci (1996).
- Wessells H, et al. Melanocortin receptor agonists and erectile response. Urology / J Urol (1998–2000).
- Hadley ME, Dorr RT. Melanocortin peptide therapeutics: melanotan analogs. Peptides (2006).
- Langan EA, et al. Melanotropic peptides: safety concerns with unregulated use. Br J Dermatol (review).
- King SH, et al. Melanocortin receptors and bremelanotide (PT-141) development. Pharmacology (review).