When was melatonin banned in Canada?

The sale of melatonin was banned in Canada until 2004, according to the Toronto Sun. Since then, the hormone has been available over the counter. Melatonin shows some efficacy for treating certain sleep disorders, states Mayo Clinic.

Melatonin is a hormone produced by the brain, and the darkness stimulates its production and release, explains Mayo Clinic. This suggests that melatonin plays a role in the regulation of sleep cycles. There is strong evidence that melatonin is useful for treating insomnia in children and the elderly, delayed sleep phase syndrome, jet lag, and sleep problems related to behavioral, mental and developmental disorders. The evidence supporting the use of melatonin to treat sleep shift disorder is weak.