Skin & Hair · Reference
Melanotan II for Men: What the Research in Men Looked At, and What to Know First
This page covers what Melanotan II is, what the studies in men measured, what changes for men day to day, how it sits with erectile dysfunction and blood pressure medication and with testosterone therapy, what a physician rules out first, and how Pepti supplies it. The general reference is what is Melanotan II.
Treatments mentioned
Melanotan II is one of the few compounded peptides whose human research was done in men: a 1996 pilot in three healthy male volunteers reported increased skin pigmentation, and two ten-man placebo-controlled crossover studies, in 1998 and 2000, reported that single doses initiated erections in men with erectile dysfunction. All of it is small, single-dose work from one research group in the 1990s, and there are no controlled trials of repeated dosing, which is how it is prescribed. For men the practical points are that spontaneous erections in the hours after a dose are expected, an erection lasting more than four hours is an emergency, and moles darken, so your skin is examined before you start. It is a compounded prescription injection and is not FDA approved.
This page covers what Melanotan II is, what the studies in men measured, what changes for men day to day, how it sits with erectile dysfunction and blood pressure medication and with testosterone therapy, what a physician rules out first, and how Pepti supplies it. The general reference is what is Melanotan II.
Melanotan II for Men
The short answer
| Question | What the live research shows | Strength of evidence |
|---|---|---|
| Has it been studied in men? | Yes; every published human study enrolled men | Small, single-group, 1990s |
| Pigmentation | Two of three healthy men showed increased pigmentation after five low doses (Life Sciences, 1996) | One three-person pilot |
| Erections | Single doses initiated erections in men with psychogenic (Journal of Urology, 1998) and organic (Urology, 2000) erectile dysfunction | Two ten-person placebo-controlled crossover studies |
| Sexual desire | Higher reported desire after active doses than placebo (International Journal of Impotence Research, 2000) | Secondary, questionnaire-based |
| Repeated dosing over weeks | No controlled trials | None |
| Does it raise testosterone? | Does not bind androgen receptors or suppress your own hormone production | Not a testosterone product |
| Moles and melanoma | Moles darken; case reports of changing moles and melanoma, causal link not established | Case reports; a reason for skin checks |
| Tested sport | Not named on the 2026 WADA list; S0 can catch compounded preparations | Check before starting |
The honest summary: real but small human signals in men for pigmentation and erections, nothing on long courses, and a skin caution that matters more than any of it.
Melanotan II for Men
What Melanotan II is, in one paragraph
Melanotan II is a synthetic, ring-shaped analogue of alpha-melanocyte-stimulating hormone (alpha-MSH), the peptide your skin releases after sun exposure to tell pigment cells to make more melanin. The ring makes it far more resistant to breakdown and more potent than the natural hormone. It was designed in the 1980s at the University of Arizona, and a metabolite of it was later developed as bremelanotide, known as PT-141. It is not selective: it activates several melanocortin receptors at once. MC1R on melanocytes drives eumelanin and the tan; MC4R in the hypothalamus and spinal cord initiates erections and is linked to sexual desire; MC3R and MC4R take part in appetite. That is why one molecule brings pigmentation, erections and reduced appetite together. It is not a hormone in the endocrine sense, it does not bind androgen or oestrogen receptors, and it is not a sunscreen.
Melanotan II for Men
What research has looked at in men
The pigmentation pilot
The direct human pigmentation evidence is a phase I pilot published in Life Sciences in 1996. Three healthy male volunteers received subcutaneous Melanotan II or saline on alternating weekdays for two weeks, with the dose stepped up. Two of the three showed increased pigmentation in the face, upper body and buttocks, measured by reflectance and by eye, a week after dosing ended.
What it shows. That the pigment pathway can be switched on in men without deliberate ultraviolet exposure, after a handful of low doses.
What it does not show. How dark, how even or how lasting a tan would be. It was a three-person, single-blind pilot designed to see whether an effect existed, not to measure it.
The erection studies
Study Who What was reported Journal of Urology, 1998 10 men with psychogenic erectile dysfunction, double-blind crossover Erections in 8 of 10; 38 minutes of tip rigidity above 80 percent on Melanotan II versus 3 minutes on placebo Urology, 2000 10 men with organic erectile dysfunction, same design Erections after 12 of 19 active injections versus 1 of 21 placebo International Journal of Impotence Research, 2000 Pooled review, 20 men Erections in 17 of 20; increased desire after 68 percent of active doses versus 19 percent of placebo What they show. That single doses of Melanotan II initiate erections in men, measured objectively on a RigiScan monitor, through a central pathway that is independent of the local blood-flow mechanism sildenafil-type drugs act on. Erections began without sexual stimulation.
What they do not show. Anything about repeated dosing over weeks, which is how it is prescribed; any long-term outcome; or a role as a treatment for erectile dysfunction. These were small, single-dose studies, the desire finding was a secondary questionnaire measure, and that signal was taken forward with bremelanotide rather than Melanotan II. Melanotan II is not approved for anything.
Appetite
Reduced appetite was recorded on the side-effect questionnaires in the human studies and is described in animal work as a melanocortin effect. No human trial has studied Melanotan II for appetite or weight, and it is not a weight tool.
Melanotan II for Men
What changes for men
Spontaneous erections are expected
In the human studies, men had spontaneous erections that came and went for one to five hours after a dose, often preceded by a stretching and yawning sensation. Prescribers describe these effects as most noticeable at the start of a course. It is worth planning around in advance, because a dose taken before work or a flight is a different experience from one taken at home. If erections are frequent enough to be a problem, even if none has lasted four hours, message your care team.
An erection lasting more than four hours is an emergency
Priapism is one of the events in the FDA's on-file safety note, and a 2019 case in BMJ Case Reports involved self-sourced product. Whatever the cause, an erection lasting more than four hours needs emergency care: call 911 or go to an emergency department. It is also why the dose is set by a physician, printed on the vial and never adjusted on your own.
Medication for erectile dysfunction or blood pressure
There is no established drug-interaction list for Melanotan II, because the trials that would produce one have not been run. That is why the intake asks for every medication you take, including anything for erectile dysfunction or blood pressure, and why a physician reviews it rather than a form. If you start any new medication of that kind during a course, tell your care team before your next dose.
It is not a testosterone booster
Melanotan II acts on melanocortin receptors. It does not bind androgen receptors, does not suppress your own hormone production and is not described as moving testosterone. Desire that faded along with energy, mood and morning erections can point at the hormonal axis, which is a separate evaluation. If low testosterone is the question, see peptides for men over 40.
Alongside testosterone therapy
No interaction with testosterone has been described, but no study has looked at the combination. List your testosterone prescription and whoever manages it on your intake. The general picture is in can you take peptides with testosterone.
If sexual function is the actual goal
Melanotan II's erectile and desire effects come bundled with pigmentation, nausea and the skin caution. PT-141, its bremelanotide descendant, was developed specifically for sexual function and its pigmentation effect is comparatively minor, and the PT-141 + Oxytocin preparation exists for the same reason. Desire and erection are also two different problems: PDE5 inhibitors keep blood vessels open once arousal has started, while the melanocortin peptides act upstream. New erectile dysfunction is a recognised early cardiovascular signal and deserves a medical workup rather than a workaround. The detail is in PT-141 vs Melanotan II and peptides for libido.
Skin checks
Melanotan II darkens existing moles and freckles; that is the pigment pathway working. Case reports describe new moles appearing and existing ones changing during use, and a small number, in Dermatology in 2014 and the Australasian Journal of Dermatology in 2012 among others, describe melanoma diagnosed during or shortly after a course. A 2017 review in the International Journal of Dermatology concluded that a causal link has not been established but that the reports justify caution. Men often have moles on the back they cannot see, so a partner or a clinician checking them matters. A personal history of melanoma or atypical moles is a stop, not a caveat. A darker tone is not protection: nothing about this medication is a reason to use sunbeds or skip sunscreen.
Fertility
None of the human studies looked at fertility; they measured pigmentation and erections after short or single-dose exposure. There is no fertility data either way. If conception is a goal in any timeframe you can name, raise it with your physician before starting.
Tested sport
Melanotan II is not named on the 2026 World Anti-Doping Agency Prohibited List. Category S0, prohibited at all times, covers substances without current approval for human therapeutic use, so a compounded preparation can fall under it. Check with your anti-doping body before starting. See peptides for athletes.
Melanotan II for Men
What a physician rules out first
A large share of low desire and erectile problems in men has a cause no peptide addresses.
| Cause | Why it comes first |
|---|---|
| New erectile dysfunction | A recognised early cardiovascular signal; needs a medical workup |
| SSRIs and SNRIs | Among the most common reversible causes of low desire and delayed orgasm |
| Beta blockers and finasteride | Each is documented to affect libido in some people |
| Depression | Loss of desire is a core symptom, not a side issue |
| Chronic short sleep | Testosterone is largely released during sleep |
| Alcohol | Regular heavy use suppresses both desire and function |
| Thyroid disease, high prolactin | Produce low desire with fatigue |
Adjusting a medication is the decision of the prescriber who wrote it, and Melanotan II is not a workaround for any of these.
Melanotan II for Men
What the evidence does not establish
- What repeated dosing over weeks does, in men or anyone. There are no controlled trials of courses.
- How dark, how even or how lasting a tan will be.
- Long-term safety over repeated courses, or whether it changes melanoma risk in either direction.
- Any effect on testosterone, muscle or fertility.
- Efficacy for erectile dysfunction or any other condition as an approved treatment. Melanotan II is not approved for anything.
Melanotan II for Men
Side effects in men
| What is reported or relevant | When | What to do |
|---|---|---|
| Nausea, facial flushing, warmth | Within an hour or two of a dose, settling the same day | Usually fades with repeated doses; tell your care team if it is a problem |
| Stretching and yawning | Often before erections | Transient; worth knowing in advance |
| Spontaneous erections | On and off for one to five hours after a dose | Expected; message your care team if frequent |
| Reduced appetite, sleepiness at the top of the dose range | Around doses | Report it |
| Moles and freckles darkening | Weeks into a course | Expected; a mole changing shape, border or texture needs looking at promptly |
| An erection lasting more than four hours | Not routine | Call 911 or go to an emergency department |
| Severe headache with visual change or confusion, or a racing heart with agitation and muscle pain | Not routine | Call 911 |
| Facial or throat swelling, difficulty breathing | Rare | Call 911, then tell your physician |
If you think you injected far more than your directions, call Poison Control at 1-800-222-1222 and message your care team. The full list is in Melanotan II side effects.
Melanotan II for Men
Where Melanotan II stands with the FDA
Melanotan II was placed in Category 2 of the FDA's 503A bulk drug substances list in 2023 and is no longer there; the FDA's list updated 14 May 2026 does not include it in Category 2. The FDA's safety-risk page, current as of 22 April 2026, keeps its original note on file: a possible immunogenicity risk from aggregation or peptide impurities, and case reports of melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism. The FDA has announced that its Pharmacy Compounding Advisory Committee will discuss Melanotan II for possible inclusion on the 503A bulks list before the end of February 2027. It remains legal to prescribe and dispense with a valid prescription, and compounded medications are not FDA approved.
Melanotan II for Men
How Pepti supplies Melanotan II
| Product | What is in it | Typical directions | Price |
|---|---|---|---|
| Melanotan II | 5 mL vial, 2 mg/mL (10 mg Melanotan II) | 0.25 mL (25 units) subcutaneously once daily Monday through Friday; 0.5 mg per dose, 20 doses | $249/mo |
| PT-141 | 5 mL vial, 2 mg/mL (10 mg PT-141) | Printed on the vial; used before sexual activity rather than on a daily schedule | $259/mo |
| PT-141 + Oxytocin | 5 mL vial, 10 mg PT-141 and 5 mg oxytocin | Printed on the vial | $259/mo |
On the Melanotan II vial, 0.25 mL at 2 mg/mL is 0.5 mg per dose (math only). Twenty weekday doses is four weeks, which is why refills run every 28 days, one vial per fill; the weekend off is part of the schedule as reviewed. Where you inject does not decide where you tan, because the signal is systemic. The arithmetic is in Melanotan II dosage. Your physician sets your directions after reviewing your intake, and they are printed on the vial.
Every price is all-in, covering medication, physician review, refill management and shipping, with no membership fee. Pepti is cash-pay and does not bill insurance. Vials arrive as ready-to-use solutions with sterile syringes and alcohol prep pads, shipped refrigerated with ice packs.
Melanotan II for Men
Where to get Melanotan II prescribed
Melanotan II cannot be bought legitimately without a prescription. The toxicity and priapism case reports the FDA cites involved self-sourced product, and research-use-only vials have no pharmacy accountable for identity, purity, sterility or concentration. The prescription route:
- Complete a free online intake covering your history, any melanoma or atypical moles, your medications (including anything for erectile dysfunction or blood pressure, and any testosterone), whether you are drug tested, and what you want help with.
- A physician licensed in your state reviews it, usually within 24 hours.
- If it is appropriate, a PCAB-accredited, FDA-registered US 503A compounding pharmacy prepares it to that prescription. Lot test results are published at /quality/lab-results.
- It ships refrigerated with your directions printed on the vial.
- Your care team stays reachable for questions and side effects.
Step by step: how to get Melanotan II prescribed online. Bloodwork is not required for any Pepti treatment. If your physician wants labs for your care, they'll ask through your account.
References
What this is based on.
References
- Dorr RT, Lines R, Levine N et al.. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study · Life Sci (1996) · PMID 8637402
- Wessells H, Fuciarelli K, Hansen J et al.. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study · J Urol (1998) · PMID 9679884
- Wessells H, Gralnek D, Dorr R et al.. Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction · Urology (2000) · PMID 11018622
- Wessells H, Levine N, Hadley ME et al.. Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II · Int J Impot Res (2000) · PMID 11035391
- Habbema L, Halk AB, Neumann M, Bergman W. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review · Int J Dermatol (2017) · PMID 28266027
- Hjuler KF, Lorentzen HF. Melanoma associated with the use of melanotan-II · Dermatology (2014) · PMID 24355990
- Ong S, Bowling J. Melanotan-associated melanoma in situ · Australas J Dermatol (2012) · PMID 22724573
- Nelson ME, Bryant SM, Aks SE. Melanotan II injection resulting in systemic toxicity and rhabdomyolysis · Clin Toxicol (Phila) (2012) · PMID 23121206
- Dreyer BA, Amer T, Fraser M. Melanotan-induced priapism: a hard-earned tan · BMJ Case Rep (2019) · PMID 30796078
- Zhang Y, Collazo R, Gao Y, Li G, Scarpace PJ. Intermittent MTII application evokes repeated anorexia and robust fat and weight loss · Peptides (2010) · PMID 20034526
Citations are provided for educational purposes. They do not constitute medical advice. Always discuss any peptide protocol with your prescribing physician.
Common questions
Melanotan II for Men, answered.
Its side effects are better recorded than most compounded peptides because the human studies were in men: nausea, flushing, yawning, reduced appetite and spontaneous erections. The serious cautions are priapism and mole changes, and there is no long-term safety data. A history of melanoma or atypical moles rules it out.
Yes, in the studies in men. It activates the MC4 receptor in the brain and spinal cord, and erections began without sexual stimulation and came and went for one to five hours after a dose. An erection lasting more than four hours is an emergency.
No. Two small single-dose studies reported erections in men with erectile dysfunction, but it was never developed or approved for that, and there are no trials of repeated use. New erectile dysfunction deserves a medical workup, and PDE5 inhibitors are the usual treatment.
The pooled 2000 review reported increased desire after 68 percent of active doses versus 19 percent of placebo, as a secondary questionnaire measure. That signal was taken forward with bremelanotide, PT-141, which was developed for sexual function.
Only if your physician has reviewed both. There is no established interaction list, so anything for erectile dysfunction or blood pressure must be on your intake, and a new prescription during a course should be reported before your next dose.
It is not described as moving testosterone. It does not bind androgen receptors or suppress your own hormone production. If testosterone is on your mind, that is a separate evaluation.
No interaction has been described, but the combination has not been studied. List your testosterone prescription on your intake.
Yes, existing moles and freckles are expected to darken. A mole that changes shape, border or texture, or any new pigmented spot, should be looked at promptly, including on your back.
No. PT-141 is bremelanotide, a metabolite of Melanotan II developed for sexual function, with a comparatively minor pigmentation effect. Melanotan II is the parent molecule and does both.
It is not named on the 2026 WADA Prohibited List, but S0 covers substances without approval for human use and can catch a compounded preparation. Check with your anti-doping body first.
At Pepti, Melanotan II is $249 a month all-in, covering medication, physician review, refill management and shipping.
No. Bloodwork is not required for any Pepti treatment. If your physician wants labs for your care, they'll ask through your account. Your skin, and any changing mole, is what gets looked at before starting. The free assessment goes to a physician licensed in your state. A consultation does not guarantee a prescription.
Next step
See what a physician recommends for you.
A licensed physician in your state reviews your intake and decides what is appropriate. A consultation does not guarantee a prescription.