Melanotropic Peptides
Abstract and Introduction
Abstract
While ultraviolet radiation (UVR) is a major cause of skin ageing and carcinogenesis, public pursuit of a novel tanning strategy circumventing the need for UVR is increasingly reported in the media and scientific press. This involves the subcutaneous self-administration of unregulated products labelled as melanotan I and/or II, synthetic analogues of α-melanocyte stimulating hormone (α-MSH), as obtained via the internet, tanning salons and gyms. The Medicines and Healthcare products Regulatory Authority has recently raised awareness of the public health risk of transmission of blood-borne viruses from the needle sharing that may occur, and of the potential impurity of these products. Dermatologists should also be aware that these agents can complicate the clinical presentation of patients with pigmented lesions; their use may be suspected in unexpectedly tanned individuals with rapidly pigmenting naevi. Meanwhile, the regulated α-MSH analogue afamelanotide (Clinuvel Pharmaceuticals Ltd, Melbourne, Australia) is showing promise for its photoprotective potential, and is undergoing phase II and III clinical trials in people with photosensitivity disorders and those prone to nonmelanoma skin cancer. The photoprotective and other biological effects of α-MSH analogues await full determination.
Introduction
There has recently been widespread media coverage of the public's use of subcutaneously self-injected melanotropic peptides, labelled melanotan I and II, for the purpose of obtaining a tan. While the exact extent to which these products are used is unknown, there is growing concern regarding the health risks of these unregulated agents, including a recent alert from the Medicines and Healthcare products Regulatory Authority. These include potential impurity of the chemicals gained from these unregulated sources, and infective complications, including transmission of blood-borne viruses from needle sharing. This topical article reviews the newly reported cases of cutaneous complications associated with use of these 'sun-tan jabs', and also discusses the background and potential applications of the regulated α-melanocyte stimulating hormone (α-MSH) analogue afamelanotide (Clinuvel Pharmaceuticals Ltd, Melbourne, Australia), which is currently undergoing clinical trials as a protective agent in photosensitivity disorders and as a prevention strategy in nonmelanoma skin cancer.