Which birth control pills don't cause weight gain?

The only contraceptive that I know that has showed weight gain in studies is the Depo Provera (the 3 month shot). None of the pills have studies that reliably showed weight gain. There are plenty of anecdotal evidences from women who claim that they do.

I think there is a reason for this. Unfortunately, but most of us gain some weight as we get older, including women in their reproductive years taking the pills. When compare the group taking the pills and group that don't, there really is no significant different in weight gains between the groups. I believe those woman who claim that they gained weight while taking the pills. That doesn't mean that there is a direct link since there are other factors in weight gain as well.