A new study conducted in the US has discovered that Pfizer Inc.’s hormones can raise the risk of death caused by breast cancer by two times.

This is the same hormone which was used by several million women to get rid of menopause symptoms. As many as 40 million prescriptions for this hormone were filled in the US previous year.

Dr Jon LaPook who is the CBS News medical correspondent, said that a new study had supported the already present evidence that it could be dangerous to take hormone replacement therapy after menopause.

Christopher Loder, a spokesman for New York-based Pfizer, said “We stand behind the current, science-based guidance in Prempro’s label, which advises doctors to prescribe the medicine at the lowest effective dose and for the shortest duration.”

He said that women who were approaching their menopause should take advice from their physicians about the duration for which they could take these hormones safely.

During menopause the body stops making hormones, estrogen and progesterone, and Prempro is a combination of these hormones which can substitute the absence of the hormones that the body stops making.