Melanotan 2

Melanotan 2

Melanotan 2 is a peptide that stimulates the body's production of melanin, the brown pigment responsible for skin tanning. It also promotes increased sexual arousal and libido, fat loss and appetite suppression.

Quantity: 10mg per vial  |  Purity: Exceeds 99% (HPLC)

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Melanotan 2, a highly potent synthetic peptide analog of the naturally occurring melanocortin known as α-Melanocyte-stimulating hormone (α-MSH), has been shown in usage to elicit melanogenic, aphrodisiac and anorectic effects in preliminary studies and clinical trials. Melanotan 2 promotes rapid endogenous melanin production, leading to drastic skin-darkening effects.

In addition to skin tanning, Melanotan 2 also stimulates increased blood flow to the genitals in men and women. This may lead to increased sexual arousal. As a result, it has been researched as a potential remedy for erectile dysfunction and female sexual arousal disorder. Further studies have shown Melanotan 2 to stimulate body fat loss, suppress appetite, enhance and maintain body composition, and improve insulin sensitivity.


The initial creation of the Melanotan II peptide is credited to a team of scientists headed by Drs. Victor J. Hruby and Mac E. Hadley at the University of Arizona. During the course of scientific research aimed at creating a drug to prevent skin cancer using the body’s natural processes, focus was placed on developing a method of stimulating melanogenesis or the production of melanin in the skin. Initially, University of Arizona scientists attempted to directly administer the naturally occurring hormone α-MSH in order to elicit this desired result.

Although this strategy exhibited promising results, it was determined that the naturally occurring α-MSH had a prohibitively short half-life to be of realistic use as a possible future therapeutic remedy. However, the positive results gleaned from α-MSH administration encouraged further research into the development of a compound that would exhibit similarly beneficial effects whilst possessing an extended half-life for functional therapeutic utilization.

Subsequent research and development yielded the synthesis of Melanotan-1, a peptide vastly more powerful in its melanogenesis-promoting effects than α-MSH. After additional studies, researchers developed Melanotan II, a compound believed to be 1,000 times more powerful than α-MSH.

Mechanism of Action

Melanocortin receptors are the primary mechanism through which Melanotan 2 exerts all of its effects. Melanotan 2, as a broad and powerful stimulator of MC-R action, has been shown in studies to exhibit appetite suppressant, lipolytic, and libido-enhancing effects in addition to promoting skin tanning.

These differing properties are thought to be a result of non-selective, but specific individual activation of melanocortin receptors MC1, MC3, MC4, and MC5. For instance, its tanning effects are believed to stem from the compound's activation of the MC1 receptor. Conversely, Melanotan 2’s effects on sexual arousal and libido may result from MC3 and MC4 receptor activation.

α-MSH and Melanogenesis

α-Melanocyte-stimulating hormone belongs to a family of hormones known as melanotropin peptides. Melanotropins, also referred to as Melanocyte-stimulating hormones (MSHs), react with the melanocortin receptor (MC-R) system to exert a wide and important range of effects in nearly all tissue types. These systemic effects include central and peripheral interaction with other prominent functional peptide-based systems (leptin, gherkin, insulin, etc).

Melanocyte stimulating hormones (MSHs) play a role in skin pigmentation by regulating production of eumelanin pigments from melanocytes as well as in the lipolysis of adipocytes, thermal control, sexual function, and cognition.

In the body, α-MSH is responsible for stimulating melanin production in the skin, a process called melanogenesis, via MC1-R interaction. Melanin is the term for a group of natural pigments found throughout the body. One type of melanin, known as eumelanin, of which there is a black-eumelanin and a brown-eumelanin, is produced by specialized cells known as melanocytes.

Melanogenesis (the formation of melanin via melanocytes) in human skin is initiated due to exposure to UV radiation, causing the skin to turn tan. A “tan” is the body’s natural defense mechanism against UV radiation by protecting skin cells with increased amounts of melanin. Simply put, the more melanin or “protective barrier” produced the darker the skin becomes.

Melanotan 2, as a longer-acting and more powerful variant of α-MSH, acts on melanocyte cells to stimulate melanogenesis and subsequently produce more melanin than they otherwise would naturally. As a result, Melanotan 2 has profound tanning effects when used in conjunction with minimal UV exposure.



Structurally, Melanotan 2 is a truncated cyclic lactam heptapeptide variant of α-MSH that has been altered to reduce enzymatic degradation (increase half-life) and enhance receptor binding (increase potency). The chemical name, Ac-cyclo[Nle4, Asp5,D-Phe7, Lys10]α-MSH4–10-NH2, signifies that the melanotan 2 peptide is comprised of the 4-10 amino acid sequence of α-MSH, but with substitutions at the 4, 5, 7 and 10 positions and a lactam bridge connecting the amino acids at the 2 and 7 positions.

In essence, Melanotan 2 is a shortened, circular analog of α-MSH consisting of seven amino acids.

Formal Name Melanotan-II
Synonyms Melanotan 2; MT-2; MT-II
CAS Number 121062-08-6
Molecular Formula C50H69N15O9
Molar Mass 1024.180 Da (g/mol)
Amino Acid Sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Peptide Structure
Physical Appearance Sterile filtered white lyophilized (freeze-dried) powder.

Dosage Guidelines

The most commonly reported Melanotan 2 dosages range from 250 to 500 micrograms (0.25 to 0.5 milligrams) administered per day. Updated protocols often suggest not exceeding a maximum dose of 1000mcg (1mg) per day. Reports indicate that starting with a low dose, then gradually increasing only as needed to achieve the desired effects, is a common practice. Read on for in depth dosage information.

WebMD advises "For causing an erection in men with ED: the typical dosage of melanotan-II is 0.025 mg/kg." and "For tanning skin: the typical dosage of melanotan-II is 0.025 mg/kg." However, lower dosages have been reported to elicit great results with less risk of side effects.

The dose of Melanotan 2 given per injection will vary with the phase of dosing protocol at which the individual is. This can range from 0.1 mg at the low end in the acclimation phase to up to 1 mg maximum in the loading phase. Importantly, exceeding 1 mg (1000 mcg) per injection is not recommended. Above this level, the risk of side effects will likely outweigh any additional benefits.

Common Phase Protocol

Effective Melanotan 2 dosage protocols can generally be thought of as having three distinct phases. These are an acclimation phase, loading phase, and maintenance phase. Experienced users may elect to skip the first phase. However, it is still good practice to follow this pattern in order to avoid unwanted side effects.

The first phase is the acclimation phase, where a conservatively low dose is taken initially so as to assess one's susceptibility to any side effects. If no adverse reactions occur after several days, the dose may be increased. The second phase is the loading phase, during which the effective dosage level reached in the first phase is taken until the desired skin tan shade is achieved. Phase three is the maintenance phase, where a lower dose is administered less frequently so as to maintain the desired skin tone.

Example Dosage Cycle

Below is an example of a common Melanotan 2 dosage cycle protocol as reported by experienced individuals. The following is not a recommendation or medical advice. It is provided for informational purposes only, which you can then discuss with your physician.

Phase 1 (Week 1):
• Day 1-4: 100mcg once daily
• Day 4-7: 250mcg once daily

Phase 2:
• Week 2-3: 500mcg once daily
• Week 4-6: 750mcg once daily

Phase 3:
• Week 7-End (as long desired): 500 mcg twice weekly

Phase 1: Acclimation

Individuals often report starting with a low dosage, in this case 100 mcg (0.1 mg), injected once daily. The injection is often administered after dinner prior to bed. If no adverse side effects are experienced after 3 days, some individuals may choose to increase the dose to 250 mcg. Again, if no side effects are experienced after 3 more days and more intense effect is preferred, the individual may choose to increase the dosage further.

500 mcg (0.5 mg) is the most commonly reported dosage amount. However, reports indicate that smaller doses may be effective for many. Healthcare practitioners advise taking the minimum effective dose, as excessive doses may cause unwanted side effects.

Depending on individual weight and skin tone preference, maximum dosage amount reported typically does not exceed 1 mg daily. This assumes that proper acclimation protocol is followed and is not recommended to inexperienced users.

Phase 2: Loading

Individuals report continuing to take the minimum effective dose (in this example 500 mcg) once daily prior to bed until they achieve their desired skin shade. In practice, reports indicate that this may take several weeks or even months.

Melanotan 2 is a minimally effective sunless tanning agent. Therefore, amount of sun or UV exposure will affect the speed at which individual tan in achieved. In the above example, the individuals experienced no harmful side effects after 2 weeks of 500mcg once daily and desired a greater tanning effect. As a result, they chose to increase the dose to 750mcg once daily for an additional 3 weeks.

Phase 3: Maintenance

In this phase, individuals sometimes choose to lower the dose to 500mcg twice weekly (spaced 3-4 days apart) now that they have attained their desired skin tan. Reports show that this maintenance phase is often sustained for as long as the continued effect is desired.

Many prefer to cease their Melanotan 2 dosage cycle after a time and begin another after giving the body a respite from continued administration. While this may or may not be physically necessary, it is important to note that no studies have been conducted on any long term effects associated with continued use exceeding several months.

Clinical Study Doses

Early dosages for Melanotan 2 in clinical studies have typically ranged from 0.01 milligrams per kilogram (mg/kg) of body weight to 0.03 mg/kg. In a pilot phase-1 clinical study, the research team recommended a single dose of 0.025 mg/kg every day for future Phase 1 studies.

So, for an 80 kilogram person, a study dose would call for about 2 milligrams, given once daily. A more conservative dosage (0.01 mg/kg) would be about 0.8 mg.

However, as mentioned previously, these recommendations are very high. Updated protocols suggest that the maximum dosage for a single day should not exceed 1 milligram, and that this amount should be worked up to slowly, especially for new individuals. Importantly, reports indicate that many individuals have not needed to use this much and have attained satisfactory results from smaller daily dosages.


Positive Results:

▪ Enhanced skin tanning
▪ Increased sexual arousal in men and women
▪ Increased fat loss
▪ Appetite suppression
▪ Improved insulin sensitivity

Melanin Production

The most commonly desired of Melanotan 2 results is a darker, faster tan via direct stimulation of the body's endogenous production of melanin, the brown pigment responsible for skin color. When the skin is exposed to ultraviolet rays, melanin production increases to protect the skin from the damaging effects of UV rays. MT-II further increases this natural production, resulting in a more rapid, darker skin tan. It is important to note that it is minimally effective at stimulating a tan without sun or UV exposure.

It was demonstrated in a pilot trail study using human subjects that significant change in pigmentation (specifically, darkening) occurred after just five applications of Melanotan 2 (applied every other day via subcutaneous injection) as measured by visual perception as well as by quantitative reflection.

The Arizona Cancer Center’s research has found Melanotan 2 to be effective in promoting skin pigmentation with little or no risk; however, its role in actually preventing skin cancer has yet to be determined. No long term study or instruction exists for Melanotan 2 peptide tanning analogs. Melanotan has been deemed not only safe by the University of Arizona, but also approximately 1,000 times more potent than natural α-MSH.

Sexual Arousal

Melanotan II and a similar α-MSH analog, known as PT-141 or Bremelanotide may enhance sexual function in males (erectile activity) and females (increased levels of sexual desire and genital arousal). Unlike other sexual-enhancement drugs, it is hypothesized that Melanotan II works at a neurological level, eliciting a more "natural" sexual response with minimal side effects. It was suggested that Melanotan II may prove equally effective in women as a treatment of female sexual dysfunction.

Multiple studies have observed that the administration of Melanotan II may increase sexual desire, which should warrant further investigation of centrally acting agents on disorders of sexual desire.

The American Association of Urologists tested Melanotan 2 extensively and found that it works through a different mechanism of action than PDE5 inhibitors, which change the blood flow or selectively expand or restrict capillaries to treat erectile dysfunction. Melanocortin peptides work by sending a signal to the brain that causes the body to naturally secrete the hormone that enhances libido. Further, melanotan 2 testing revealed that sexual desire and genital arousal also increased in women as well.

Fat Loss and Appetite Suppression

α-Melanocyte-stimulating hormone, of which Melanotan 2 is an analog, is the primary endogenous stimulator of the melanocortin system in humans; α-MSH is stimulated by leptin. The production of, and sensitivity to leptin is typically impaired in obese subjects.

On the topic of MTII as a potential obesity treatment agent: MC3R has been suggested to play a role in nutrient partitioning. Although agonists of the MC3R would not be expected to produce dramatic weight loss, they may favor a more beneficial partitioning of nutrients. Development of dual MC4 and MC3 receptor agonists has been addressed in order to reduce weight dramatically, as well as improve the metabolic co-morbidities of obesity significantly. Melanotan 2 binds to both of these receptors.

Further, Melanotan 2 results extend to fat loss in clinical studies, resulting in favorable effects on body composition. This effect is thought to occur through two different mechanisms. One common side effect is appetite suppression. This leads to decreased caloric intake, which can lead to increased fat burning and decreased body fat accumulation.

However, studies have indicated that it has direct effects on fat burning as well. A 2007 study performed on mice demonstrated that it resulted in reduced weight and body fat in obese subjects. An additional study had similar findings, concluding that melanotan peptides likely reduced body fat through enhanced lipid mobilization, or the burning of body fat for energy.

Insulin Sensitivity

Melanotan 2's positive effects on body composition may be further amplified by increasing the body's sensitivity to insulin. Studies performed on rodents indicate that results may include increased insulin sensitivity, improved glucose tolerance, and enhanced insulin-mediated glucose disposal. In humans, improved insulin sensitivity enhances the body's ability to gain and maintain muscle mass, whereas impaired insulin sensitivity can lead to increased fat gain and reduced lean muscle.

Side Effects

Side Effects

Melanotan 2 is usually well tolerated and most users report little to no side effects. At recommended low (but effective) dosages, the most commonly reported side effects are mild facial flushing, nausea, dizziness, and lethargy. These typically pass quickly, often within a matter of minutes or seconds. Further, also common among male users is the appearance of spontaneous erections. Still, users may be indifferent to this side effect or even look upon it as a benefit. Less common but more severe side effects may occur with excessively high dosages. However, most users of the Melanotan 2 peptide will find any side effects that do occur to be mild and manageable. It is crucial to start with a low, conservative dose and increase gradually, only when sure that the smaller dose is well-tolerated.

In clinical studies, any side effects reported were generally mild and short-lived. Importantly, any harsher side effects that did occur were correlated with extreme dosages, sometimes 6 or more times over the recommended maximum.

Potential side effects include:

▪ Flushing (especially of the face and chest)
▪ Dizziness, nausea and vomiting
▪ Fatigue/lethargy, yawning
▪ Headaches
▪ Appetite suppression
▪ Stomach pains and cramping
▪ Constipation
▪ Spontaneous penile erections
▪ Muscle pain
▪ Bloating, flatulence
▪ Back, liver, and kidney pain
▪ Formation of new moles and freckles
▪ Darkening of existing moles and freckles

Commonly Experienced

The most common side effects experienced with Melanotan 2 use are facial flushing, dizziness, dull headache, and nausea. These side effects generally manifest shortly after injection and clear up quickly. Spontaneous erections have also been reported in male users. Indeed, the peptide has been researched as a libido enhancement aid by the pharmaceutical industry as it has been observed to increase blood flow to both the male and female genitalia in clinical study. Some users also report a reduction in appetite.

Rarely Experienced

With extreme dosages, less common but more severe side effects can occur. Gastrointestinal effects include constipation, bloating, and flatulence, along with upset stomach and stomach cramping. Other side effects include body pains in the muscles, liver, and kidneys. In addition, excessive doses may aggravate an individual’s pre-existing allergies or hypersensitivities, including asthma. The appearance of this effect is an indicator that the dosage is too high and needs to be reduced. Some users have also reported the formation of new freckles as well as the darkening of existing freckles. This effect is similar to the response skin has to natural sun exposure, an effect which typically goes away along with their tan if sun exposure is reduced or eliminated. However, the use of Melanotan 2, along with all tanning and sun exposure, should be halted immediately if any signs of skin cancer are suspected. Indeed, if any abnormal reactions do occur, use should stop immediately and medical attention should be sought.


Melanotan 2 HPLC

Mass Spec

Melanotan 2 Mass Spectrometry