I use only Doterra products. What is do when I have a certain problem I google which essential oil is good for such and such, and I read everything I can that comes up. I then go to the Doterra.com site and look for the oil or oils that were recommended and read whatever Doterra has on it, and go from there. I once had a boil, which I had never had and it scared me because I did not want to go to doc, I knew what they would do, lance it. I looked up oils that are good for that, and I happened to have some of them. I got rid of my boil in 3 days. It was unbelievable. I have a book called "Essentials of The Earth" available on amazon, it has tons of information, great, great book. I believe the latest edition is the 11th. It lists all kinds of illnesses and diseases and which oils to use. It also list all the different oils and what they are used for, how to use them and their safety. All oils should always be diluted, some are what they call "hot" and it will tell you about them and how to use. Please do your research, there is much to learn about them.
Good luck,
Blessings