I'm just trying to get the same feel out of vaping that I did with analogs. This can't be more harmful than those. Can it? 1 drop vaped per day seems minuscule.
if "pf" is PassionFlower, and "drops" are an extract, then off the top of my head i would say this (but agreeing with the other poster, it is NOT advice - you must research all things that you do, and have a firm understanding within yourself):
1. Harmine/Harmaline will make you very sick if you get close to ODing, the kind of sick you do not want to ever experience. nauseated, dizzy, heart-rate/blood-pressure things, vomiting, cramping, just very intensely ill. more than a 100mg might be lethal in combination with other things, and even if you fasted for days and had perfect health, more than a gram might very well be lethal by itself. but then again, a dozen grams of table salt is lethal. but less than 25mg in a day (not per dose) is probably OK, but probably will have negative physiological effects in the long term, and probably will cause headaches with cheese/beer/etc - foods containing Tyramine. in all cases, you should NEVER use them if you are taking ANY medications, whether prescription or over the counter. i would guess 1mg (or less) of a Harmala extract would be a fair test case in a person with no health problems and under no medication. but it is important for anyone trying that to do all research themselves. typically, they make almost any medication many times more powerful - but that alone may not be a good thing, especially with something that can be habit-forming, especially with something that is used daily.
2. if anyone does try such a thing, it is important to educate others, so they can add to their knowledge base. it is important to state what your current state of affairs are, exactly what you did - with all details, and then what you noticed afterwards.
3. IMHO, the goal would be something satisfying, non-habitual, and without any long-term harmful effects. personally, i still smoke 3-5x/day (cut back from almost 40!), and find that i vape more than i really would like to (like 30 minutes at a time or even more sometimes), and i have difficulty stopping vaping when i have other things to do - i keep waiting for that "i am done" feeling that doesn't arrive, and vaping does make me sleepy and tired more than usual. personally, i wish i had an e-liquid that made me want to stop after 10 hits, and then allowed me to have the relaxed powerful subtly energized intent/focus for 1+ hours afterward that tobacco gives me.
anyway, if "pf" is PassionFlower extract, i look forward to hearing any results of your experiment, including all details/amounts/concentrations/brands/usage and before & after subjective experiences, etc.