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Contact Us

Thank you for contacting the Ontario Health Study. Due to the COVID-19 Pandemic, the OHS team is working remotely.

We’re still available to help you, however we ask that you do not leave a voice message, as we are temporarily unable to return your call.

Instead, please email us at

Our hours of operation remain the same – Monday to Friday from 9am to 5pm. Thank you for your patience and we apologize for the inconvenience.

If you feel you need more information than what is provided on this website, please call 1-866-606-0686 to speak with a member of our Study Team. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m. Please note that if you leave a voicemail, an OHS staff member will return your call. If you are not available at that time, the OHS will leave a voicemail for you if the feature is available.


For Participants, the Public, and Researchers:


Ontario Health Study
MaRS Centre 661 University Avenue, Suite 510
Toronto, ON
M5G 0A3