The Family Health International's researchers have revealed that women do not put on weight as a result of consuming contraceptive pills. David Grimes of the research center said that the belief weight is gained as a result of contraceptive pills is only a myth, and that such beliefs are not based on facts.
The researchers compiled the results of 44 studies carried out over the past few years that examined the effects of contraceptive pills and patches. As they report in The Cochrane Database of Systematic Reviews1, they found no evidence that beginning of the use of the pill leads to any jump in weight gain. There are many brands of the pill on the market, but all contain a synthetic version of the hormone progesterone, usually together with synthetic oestrogen, which stop the body's natural production of these hormones and prevent ovulation.
Some doctors believe that these hormonal changes can also stimulate increased appetite, causing women to put on weight. And many women believe that they piled on the pounds after starting on the pill. But Grimes and his colleagues' data suggest that this supposed 'cause and effect' is merely anecdotal, and that patterns of weight gain among new pill users are no different to those seen in the population at large.
The only logical explanation to increased weight could be that most people add on pounds as a result of age. Of the 44 studies collated by Grimes' group, only three compared the effects of the pill with those of a placebo, the ultimate test of whether the contraceptives cause any discernible change. Such studies are difficult to carry out, in part because of the ethical implications involved in prescribing a placebo to women who do not want to conceive. These studies showed no difference in weight gain between those on the pill and those not. Nor was there an effect on appetite.