Body & HealthFact
The cheap drug contains the same active ingredient as the expensive one.
A generic is a copy of an original drug after its patent expires – same active ingredient, same amount, same form. Makers must prove bioequivalence: blood levels within 80–125 % of the original. Differences lie in fillers, colour and shape. Patents usually run 20 years from filing.
Useful: The brand name on the box says little – the ingredient name below it is what matters.
Source: en.wikipedia.org