Why is Circadin® only for people aged 55 and over? Can Circadin® be used in adult patients younger than 55 years?

Circadin^® works by increasing the levels of melatonin in the body¹. There is a general decline in melatonin production with age^{26 21 27}. Also, insomnia sufferers have shown poorer melatonin production than people without insomnia across all age groups⁵. Therefore, the impairment in melatonin production as a result of ageing may be a cause of insomnia.

Insomnia sufferers aged 55 years and older were selected to be studied in clinical trials as they would, theoretically, have poorer melatonin production (due to both age and insomnia) and were hypothesised to benefit the most from therapy with Circadin^®1. As there are large inter-individual variations in ‘normal’ physiologic levels of melatonin across (as well as within) age groups, younger adults with insomnia may benefit from Circadin^®. Circadin^® was given to insomnia patients aged 20-80 years in clinical trials showing its safety for 6 and 12 months^{11 20}.
However, the current indication for Circadin^®, as stated in the Summary of Product Characteristics (SPC), is for use in people aged 55 and over¹. The physicians would need to make their own clinical judgement, in consultation with the patient, if they were to use Circadin^® to treat younger adults suffering from insomnia.