Aside from legal issues, it is very important to know the herb/EO's interactions because you CAN hurt someone. You would not want to give a blood pressure raising EO to someone with high blood pressure, or one that drops BP to someone who is on medication. There are many, many interactions and while they are taking prescription drugs it is not wise to offer the muscle relaxant, smooth muscle relaxing EO's, as it could be too much. Each person is affected to a different extent by drugs and by EO's, so you just don't know how much may be too much when mixing them (drugs and EO's). There are certainly some that are safe for most people (ie. lavender), most of the time, so sticking with those types should be fine, but it sounds like you want to do more. Not to be unkind or disrespectful, but until, and unless you study a lot, I would recommend staying away from the analgesic types of EO's until they are off meds and their health is more stable.