Stay away from most gas station Kratom. Find a good online source and read the reviews. A particular brand, OPMS I'm sure has been adulterated with a bath salt type substance acting like speed. Stay away! It comes in a silver or gold version.
The red maeng dai is my favorite for its calming effects, it just takes so much to feel anything. Close to 10 grams. Concentrated drops are a good alternative, and capsules if you want to take 10 of them. All this on an empty stomach. It will curb opiate cravings,yet after several weeks you will experience similar withdrawls.
Kratom is illegal in most countries they are produced in and several states in the us. You never know what's in it. The greener the color the fresher the product. STAY AWAY FROM O.P.M.S.