hi there, firstly i am glad you have asked about the oral contraceptive pill. This is a myth. It does not cause weight gain. older generation contraceptive pills such as triphasil and minerva did cause a small measure of fluid retention but even that was minimal and did not increase weight in women taking them. Newer generation pills like oralcon (also known as Nordette) does not cause weight gain or fluid retention. there is however evidence for the contraceptive injections Depo-Provera and Nur-esterate causing small amounts of fluid retention and weight gain due to dramatic changes in hormone levels and appetite. A review of 44 studies showed no evidence that birth control pills caused weight gain in most users. And, as with other possible side effects of the pill, the minimal weight gain is generally temporary, going away within two to three months. if you require evidence i will send you links to various research studies done proving NO weight gain as a standard side effect. weight is caused by eating too much and exercising too little! Definitely not the pill