You're absolutely right about that. ...OTC version is a huge market than Rx!
I'm sure you heard bout Xenical 120mg is used by certain overweight people, such as those who are obese or have weight-related medical problems. If you ask these folks to visit a doctor to get Rx meds they MAY NOT (for various reasons). But for some reason the same folks would grab a bottle in a supermarket (reason- convenience/privacy/no need to discuss all of their issues etc)..for that reason ALLI was born an OTC version 60mg.
Let's talk bout sales Rx 120mg (Roche): around 100mil/yearly (total sales In 5 yrs <300/400 mil )
OTC 60mg (GSK): 1st year alone over 1 billion (not M but B) in here GSK is the winners!
Imo: it's psychology played a major role. The same applies here with our B for UC.