Health expert says Melanotan II darkens skin moles and can make melanoma hard to detect Herald Sun Avoid nasal tanning sprays or nasal tanners entirely. These products promise an all over tan without sun exposure but they are unregulated, can be unsafe, and contain potentially risky substances like Melanotan 2. Melanotan II A Sun Kissed Look, and a Confident You. Health warning over 'dangerous' self tan product after increase in ads