Melanotan II (Melanotan 2)

Melanotan II (Melanotan 2)

Melanotan II is a synthetic analog of the naturally occurring melanocortin peptide hormone alpha-melanocyte stimulating hormone (a-MSH). This peptide was developed by the University of Arizona.  In preliminary studies and clinical trials it has been shown to have melanogenesis (tanning) and aphrodisiac effects.
Melanotan II was developed at the University of Arizona as a tool to prevent skin cancer.  The researchers understood that one of the best ways to prevent skin cancer was to have melanin activated in the skin.  This process is what causes a tan to the skin.  The researchers believed they could reduce the risk by triggering the body's natural pigmentation to tan before UV exposure.  In nature the UV exposure causes production of the hormone a-MSH.  This causes melanogenesis (tanning) by triggering the melanocytes (skin's pigment cells) to produce the skin pigment (melanin).  The researchers at the University of Arizona hypothesized that by introducing the a-MSH hormone directly into the body they could produce a sunless tan.  During initial studies this method appeared to show results.  However the short half life of naturally occurring a-MSH made it impractical to use as a therapeutic drug.
This led researchers headed by Victor J. Hruby and Mac E. Hadley to synthesize and study hundreds of molecules.  They eventually located a peptide, [Nle^4, D-Phe^7]-a-MSH, that was roughly 1,000 times more potent than naturally occurring a-MSH.  This new molecule peptide was named "Melanotan"; later Melanotan -1 and presently known as afamelanotide.  The researchers then developed another analog, Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2.  This peptide molecule was named Melanotan II, also known as Melanotan 2 or MT2.  The scientists were hopeful these peptides could be used to prevent melanoma by stimulating pigment production without needing harmful exposure to UV radiation.  This would then reduce the amount of skin damage and lower to possibility of skin cancer potential.  
Pilot Phase 1 clinical trial was conducted on males in in Tucson at the University of Arizona and published in 1996.  The study published that they found Melanotan II promoted tanning activity in humans given only 5 low doses every other day by subcutaneous injection.  The reported side effects were mild nausea and a "stretching and yawning complex" that coincided with penile erections.  Since this study there have been numerous other studies conducted that also reported melanogenesis (tanning) and sexual arousal in both males and females.  These studies will be further explored in future articles.

What are Peptides?

Peptides are naturally occurring biological molecules.  They are short chains of amino acid monomers linked by peptide bonds.  Peptides are distinguished from proteins on the basis of size.  This number is usually distinguished by 50 or fewer amino acids.  Proteins are polypeptides that are more complex.  Intake and production of all the amino acids is necessary for the production of all the peptides needed for the body to operate efficiently.

Peptides are created through peptide synthesis.  This is the combination of amino acids that are connected through peptide bonds.  Peptides are synthesized by coupling the carboxyl group or C-terminus of one amino acid to the amino group or N-terminus of another. There are two strategies for peptide synthesis: liquid-phase peptide synthesis and solid-phase peptide synthesis.


In 1901 the first synthetic peptide was discovered by Emil Fischer working with Ernest Fourneau.  It was not until 1953 that the first polypeptide was synthesized by Vincent de Vigneaud.  This peptide synthesized by de Vigneaud is the popularly know Oxytocin.  Oxytocin is produced naturally in the brain by the hypothalamus where it is transported out before being secreted by the pituitary gland.  This peptide serves many purposes in the reproductive cycle such as triggering child birth and also during breast feeding.  This peptide also creates a sense of trust and well being in the brain.  


Peptides have a wide range of applications in medicine and biology.  They are what regulate most physiological process of the body.  From the endocrine system to growth factors and neurotransmitters, peptides signal the body in numerous ways.  Insulin was the first therapeutic protein to be introduced to help treat Diabetics in the 1950's.  Since then over 60 different peptide drugs have been approved by the FDA for use.  There are about 140 currently in clinical trials and another 500+ peptide drugs in pre-clinical development.

Knight Peptide will continue to explore the world of peptides and be a place of education.