You can’t walk into the factory but certainly you can look at a patented drug and get a formula, for example. The Wikipedia article about Sovaldi (sofosbuvir

You can’t walk into the factory but certainly you can look at a patented drug and get a formula, for example. The Wikipedia article about Sovaldi (sofosbuvir - a Hepatitis C drug) contains the exact chemical formula. Plus the clinical trial process is extensive. It would be much harder in the present regulatory regime to have a new BS prescription drug than a new BS testing startup, like this one or Theranos. (Old drugs are a little different - some were grandfathered into the current testing regime and evidence for their effectiveness is in some cases limited.) Certainly there are trade secrets in medicine, but not everywhere.