How much BLOOD does your weed have in it? Was it fertilized with BLOOD?
If the answers to these questions are "NONE" and "NO" _AND_ it is a prescribed "medication," _AND_ it is not being smoked, then I *think* the WTB&TS would have nothing to say.
The Watchtower is anti-smoking and anti-recreational substances that are not prescribed, regardless of the "naturalness" of the substance.
The WTB&TS has no problem with homeopathy, by the way, because it is based on a dilute extract of baloney and bullshit.