Do weight-loss pills affect the effectiveness of birth control pills?

Do weight-loss pills affect the effectiveness of birth control pills? I keep seeing ads for this Avectar something or other weight-loss product and what it claims to do is amazing. I%26#039;m curious as to how weight-loss supplements affect birth control users. Birth control is my main form of contraception.
http://bytead.com/free-15days-hoodia/

overall this will be a temporary way to get over a weightloss plateau... but it will work...
take care :) 33% 1 Vote