About us


Ninotalem® − High quality melatonin tablets

Melatonin, a natural hormone, plays a vital role in regulating the circadian rhythm (or ‘biological clock’) of the human body. Disturbances of the body’s melatonin levels are implicated in a variety disorders, ranging from sleep disturbances and jet-lag to seasonal affective disorder (a type of depression). In addition, melatonin is a potent antioxidant, can positively affect immunodepression and has shown positive results as an adjuvant to certain types of cancer therapy.

Circa Dia has developed Ninotalem® tablets that contain synthetic melatonin of high quality and consistency. Circa Dia’s Ninotalem® has been extensively tested in formal toxicology studies and in several clinical studies involving more than 1,000 subjects. All with clear and positive results. Based on these results, Circa Dia has been granted a product license for Ninotalem® by Health Canada for use in sleep disorders.

Circa Dia is now looking for partners to develop additional melatonin-based drugs for both adults and children and to develop the Canadian market (and others) for Ninotalem®. Circa Dia is also open for discussions on product licenses for Ninotalem®.

Company profile

Circa Dia B.V. is a privately held company founded in 1998 and located in Amsterdam and The Hague, The Netherlands. The company builds on longstanding melatonin research by renowned melatonin expert Wop J. Rietveld, MD, PhD, chairman of the International Society for Chronobiology and Scientific Director of Circa Dia.


Circa Dia B.V. - Herengracht 124 - 1015 BT Amsterdam - The Netherlands
T +31 (0)20 5205820 F +31 (0)20 5205810 E Elke.van.Wachem@circadia.nl