This is an additional supplement that seems to make my husbands restless legs medication work better. I originally ordered it to see if it would help keep him from needing a stronger prescription. Aparently that is the only reason he hasn't had to increase his prescription dose. We tried skipping it for a week and it is apparent he needs this Formula 303. They do have a strong odor when you open the bottle and I even put the bottle in a storage bag after preparing each weeks supplements. Other than that, it is great and LOVE Earth Turns very PROMPT Shipping!!!!!