Big pharma absolutely can patent drugs extracted from herbs. The reason you don’t see lots of them is that lots of them didn’t work very well and the ones that did were all isolated and turned into medicine decades ago, so the patents have expired, and they’re generally sold under medicine-sounding names rather than the names of the plant them came from. E.g. Aspirin was originally made from modified willow extract, and was discovered because willow was a known natural remedy and so was a good candidate for further investigation. Also, the requirement that a newly discovered drug needs to be proven to be effective to be licensed is a big hurdle lots of natural remedies don’t manage to clear.
Even despite that, though, big pharma does sell natural remedies. The difference is that they don’t claim they’re medicine. If they only claim they’re a food supplement or something else that’s only medicine-adjacent, there’s no requirement to prove efficacy.
Big pharma absolutely can patent drugs extracted from herbs. The reason you don’t see lots of them is that lots of them didn’t work very well and the ones that did were all isolated and turned into medicine decades ago, so the patents have expired, and they’re generally sold under medicine-sounding names rather than the names of the plant them came from. E.g. Aspirin was originally made from modified willow extract, and was discovered because willow was a known natural remedy and so was a good candidate for further investigation. Also, the requirement that a newly discovered drug needs to be proven to be effective to be licensed is a big hurdle lots of natural remedies don’t manage to clear.
Even despite that, though, big pharma does sell natural remedies. The difference is that they don’t claim they’re medicine. If they only claim they’re a food supplement or something else that’s only medicine-adjacent, there’s no requirement to prove efficacy.