Naltrexone is becoming increasingly well known for the major role it has played in the heroin epidemic. Naltrexone is able to reverse the effects of an opioid (e.g. heroin, OxyContin, etc.) overdose and can save lives. The drug is also well-known to reduce alcohol intake in both animals and humans, making it a potential treatment for alcoholism and binge-drinking disorders.
New animal research suggests that melanotan 2 (MT-2), a peptide that has been associated with increased skin pigmentation and sexual arousal, may augment the effects of naltrexone when it comes to reducing alcohol consumption. It works much like Sermorelin. This finding reinforces previous speculation that MT-2 and other melanocortin receptor agonists interact with opioid systems to modulate pain, drug tolerance, and food intake.
MT-2 Alcohol Effects
Naltrexone alone affects alcohol consumption only moderately, reducing drinking by a small percentage. MT-2 also has moderate effects when administered by itself in animal models, reducing ethanol consumption by about 20%. However, when MT-2 and naltrexone are combined, the effects are startling. In recent scientific animal studies, consumption of ethanol, even with low doses of MT-2 and naltrexone, is reduced by nearly eight-fold over what naltrexone or MT-2 alone can produce .
Further research in mice has indicated that the effects of MT-2 on alcohol consumption are most likely mediated by action at the melanocortin 4 receptor (MC4R) . There are five known melanocortin receptors, each producing different properties when a molecule binds to them. MC4R has long been-associated with food intake, metabolism, and sexual desire. It is generally accepted that these effects are produced in the central nervous system, suggesting that melanocortins can directly influence behavior by influencing desire (e.g. increasing sexual desire while decreasing desire for food).
MT-2 Offers New Insight
The most recent scientific animal studies regarding melanotan 2, MT-2 and alcohol consumption are just months old. They are, however, the latest in a string of findings regarding MT-2 and behavior. The peptide works to modulate brain activity in a way that nothing ever has. It doesn’t just alter general levels of neurotransmitters, but targets specific neurotransmitters and specific neurons to affect specific types of behavior. MT-2 is expanding our conception of behavior and may open doors to the development of targeted medications that can finally provide behavior-specific modulation. The willpower answers may be just around the corner.
 M. Navarro, F. Carvajal, J. M. Lerma-Cabrera, I. Cubero, M. J. Picker, and T. E. Thiele, “Evidence that Melanocortin Receptor Agonist Melanotan-II Synergistically Augments the Ability of Naltrexone to Blunt Binge-Like Ethanol Intake in Male C57BL/6J Mice,” Alcohol. Clin. Exp. Res., vol. 39, no. 8, pp. 1425-1433, Aug. 2015.
 J. J. Olney, G. M. Sprow, M. Navarro, and T. E. Thiele, “The protective effects of the melanocortin receptor (MCR) agonist, melanotan-II (MTII), against binge-like ethanol drinking are facilitated by deletion of the MC3 receptor in mice,” Neuropeptides, vol. 48, no. 1, pp. 47-51, Feb. 2014.