If two oral drugs with the same dose and the same active ingredient are to be compared, both are considered equivalent (for example, a generic drug compared to an original) if they reach the site of action with comparable speed and to a comparable extent. In the case of generics, it is mandatory that the bioavailability of a generic drug is between 80% and 125% (with a 90% confidence interval) of the original. Then the preparations are considered bioequivalent.