October 3, 2002
Question from Mississauga, Ontario, Canada:
My wife and children just emigrated to Canada from India, where the insulin they were using was U-40, but I heard that in Canada the insulin is U-100. What is meaning of these units? What is their significance?
Clinically and in manufacturing amounts of insulin have always been expressed as Units rather than micrograms. U-40 means that the ampoule of insulin contains 40 units per ml. Likewise U-100 insulin, which is the standard in North America, contains a100 units per ml.. Disposable syringes here are calibrated in Units for U-100 insulin. Put another way the U-100 insulin is two and a half times as concentrated as the U-40.
[Editor’s comment: As long as you match the insulin concentration with the right syringe, there should be no problem in converting to U-100 insulin.