Researchers at Oregon Health & Science University claim the commonly held belief that taking the pill makes you pile on the pounds simply isn't true.
The scientists carried out tests on rhesus macaque monkeys - whose reproductive systems are almost identical to ours - to get to the bottom of the argument. This type of study, they claim, can be more accurate than a human study, since things like food intake can be controlled more easily in monkeys.
At the start of the study, half the monkeys were of a normal weight while the other half were overweight. The animals were given the pill at the same relative dose as that given to humans for eight months. During that time their weight, food intake, exercise levels and body fat were all tracked by the researchers.
At the end of the study the results showed the monkeys who were of normal weight at the beginning had remained stable. And perhaps more surprisingly, the overweight monkeys had actually lost 8.5 body fat.
According to the researchers, this means overweight women who stick to a stable diet could actually lose weight while taking the pill. There again, if something happens in tests involving monkeys, it doesn't guarantee the same will happen in humans. But the researchers are confident enough in their results to suggest women shouldn't be worried about weight gain while taking the pill.
Have you stopped taking the pill because of the effect it's had on you?