Sharing because I found this very interesting.
The Four Thieves Vinegar Collective has a DIY design for a home lab you can set up to reproduce expensive medication for dirt cheap, producing medication like that used to cure Hepatitis C, along with software they developed that can be used to create chemical compounds out of common household materials.
The most notorious is probably thalidomide, but there are plenty others on this list of withdrawn drugs that cause long-term side effects.