China's food and drug watchdog has started to collect material on negative reaction of contraceptive pills following a WHO cancer agency report that they may cause cancer.

The International Agency for Research on Cancer under the World Health Organization (WHO) concluded late last month that a common type of contraceptive pill, taken by about 10 percent of women of reproductive age, increases the risk of more types of caner, reported Associate Press on July 30.

The State Food and Drug Administration has started to collect information on whether they have carcinogenic effect and officials said they will notify the public if their studies conform with the agency's findings.

The agency has determined that the pill combining estrogen and progestin can not only cause liver cancer as previously believed, but slightly increases the risk of cancer and cervical cancer, the report said.

Meanwhile, the agency also said the pill protects against endometrial and ovarian cancers.

An official surnamed Lu with the family planning commission in Hangzhou city, east China, said he believed using contraceptive pills are safe as those which are used in China are all of small dosage.

Still, gynecologists suggested women to take small doses of contraceptive pills and said the better way is to first go through medical checkup and listen to doctors' professional advice.

Taking contraceptive pills has some side effects on certain people, such as nausea, vomiting, fatigue or irregular menstruation.

(Xinhua News Agency August 5, 2005)