I don't think you'll find one that says "for internal use"
When I took it I just used the external use... all these oils all the same stuff anyway in this regard.
This is what I took:
www.amazon.com/NOW-Foods-Cinnamon-Cassia-ounce/dp/B000W3X4PI but I got it form the local health store.
PS - The stuff wrenches your gut if you don't put it in a capsule. And even then... Take it with food for the least gut wrenching experience.
EDIT: Both WOO/Thyme and in the beginning cinnamon oil all helped me but the major change or "click" didn't occur until I added Vitamin D3 (3,000 iu) and Vitamin A (3,000 iu) daily along with the WOO/Thyme Oil at the same time. This was like some sort of one two punch for whatever was going inside of me.
I'd try adding Vit D&A to the WOO for sure.
Post Edited (Canada Mark) : 11/30/2014 4:00:32 PM (GMT-7)