1. Milk Thistle is NOT water soluble,so you are not getting anything from it, it has to be eaten, or put into capsule or tincture for any benefits to be gained.
2. Herbs cause change. Yes you can buy them at any health food store, but change can happen and does so it is best to consult an herb book or an herbalist( good books for just starting out are by Susun Weed and Rosemary Gladstar; on the web or library or stores)
3 Some "safe" herbs to use are Nettles, Red Raspbery, Red Clover, Oatstraw, these herbs contain high amounts of vitamins and minerals and can be taken as an infusion- 1/4 herb in mason jar with hot water, laft to steep at least 2 hours preferably overnight.
4. Again, I cannot stress enough that herbs are medicine and can cause damage if not used properly, please do yourself a favor and look into some books, you may just develop a life long love.