There have been some side effects reported while using Melanotan 2, typically these effects appear during the first few days of dosing and will become increasingly less obvious as the body adjusts to the peptide. These effects include: nausea, appetite loss, drowsiness and increased sex drive. In order to combat nausea, an anti-histamine can be taken when injecting until the body gets used to it. But most common way to deal with this is to inject Melanotan before bed, this is also beneficial to combat any drowsiness.
^ Jump up to: a b Low TL, Hu SK, Goldstein AL (February 1981). "Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations". Proceedings of the National Academy of Sciences of the United States of America. 78 (2): 1162–6. Bibcode:1981PNAS...78.1162L. doi:10.1073/pnas.78.2.1162. PMC 319967. PMID 6940133.
Oxytocin is a peptide of nine amino acids (a nonapeptide) in the sequence cysteine-tyrosine-isoleucine-glutamine-asparagine-cysteine-proline-leucine-glycine-amide (Cys – Tyr – Ile – Gln – Asn – Cys – Pro – Leu – Gly – NH2, or CYIQNCPLG-NH2); its C-terminus has been converted to a primary amide and a disulfide bridge joins the cysteine moieties. Oxytocin has a molecular mass of 1007 Da, and one international unit (IU) of oxytocin is the equivalent of about 2 μg of pure peptide.
Potential side effects of 5-HTP include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, vivid dreams or nightmares, and muscle problems. Because 5-HTP has not been thoroughly studied in a clinical setting, possible side effects and interactions with other drugs are not well known. According to the US National Institute of Health TOXNET, 5-HTP has not been associated with serotonin syndrome or any serious adverse events in humans. Across multiple studies, 5-HTP also been reported to not cause any noticeable hematological or cardiovascular changes. 5-HTP also has not been associated with eosinophilia.