Introduction: The interest on melatonin (MLT) as a psychiatric treatment has increased a lot in the last decade. This is mainly due to MLT safety and its lack of serious adverse reactions. The aim of this paper consists of reviewing the adverse effects to MLT consumption in humans.
Method: A 35-year (1966-2000) bibliographic search using the Medline database was carried out. The intersection of the key word melatonin with the group of words adverse effects or side effects or adverse reactions or toxicity was the strategy of the search.
Results: 307 articles were elicited and 9 were related to MLT adverse effects. The range of MLT dose involved in the adverse reactions oscillated between 1 mg and 36 mg. The adverse reactions were: one patient with autoimmune hepatitis, one case of confusion due to MLT overdose, one case of optic neuropathy, four subjects with fragmented sleep, one psychotic episode, one case of nistagmus, four cases of seizures, one case of headache and two cases of skin eruptions.
Conclusions: Attention should be paid on the necessity of enquiring about the drugs that patients are taking, because this product is not harmless for health.