A big reason why big pharma doesn't get involved is because anyone can basically compound finasteride. You don't necessarily need a prescription. Therefore, they cannot patent it. How these pharmaceutical companies make their money is through the patent. For a long time there was no generic Propecia, you either had to get Propecia or Proscar. Having a monopoly on a medication is how they make money. Some pharmaceutical companies can raise the price of a medication by an insane number, and if they're the only ones who can make and distribute the medication the public has no choice. However, over-the-counter supplements are not as lucrative.