This seems to be a common misconception. You can’t patent a compound. They patent the manufacturing process for creating/purifying/etc the compound in a particular form (pill/liquid/stabilize/whatever) as well as the use of the compound in a particular form to treat a disease that they themselves have done the clinical trials in (guaranteeing that their form of the drug is the only one that has FDA approval)
They can do that with a natural compound as easily as with one they created in a lab.
This is why they can charge $1 for a pill of propecia even though the active chemical finesteride has been out of patent protection for ages.
