New Pill will allow women to have just three periods a year

Women, rejoice. Painful periods – in fact monthly periods, altogether – could soon be a thing of the past. A new version of the Pill having clinical trials in America will let women lengthen their menstrual cycle to three or even four months, and mean they need have only three or four periods a year.

The pill, called "Seasonale", is identical to the standard contraceptive Pill, and contains the same combination of female hormones, though with different packaging. It could go on sale early next year. Barr Laboratories has licensed the technology from Eastern Virginia Medical School, Virginia, which patented the concept.

A Dutch study found 70 per cent of women between 15 and 50 would prefer to have their periods less frequently, suggesting the new Pill would be widely popular.

The technique might even prolong fertility, says Roger Gosden, scientific director of the Jones Institute at Eastern Virginia Medical School. "It might be that if you retain the eggs, the quality [later on] might be better. The window of fertility could be held back."

It will not harm the chance of women becoming pregnant if they stop taking it, says Professor John Guillebaud, an independent gynaecologist who is medical director at the Margarete Pyke health centre in London and author of The Pill.

He already prescribes extended courses of the Pill for women who suffer badly from period cramps or headaches, or who want to delay menstruation for a few days, say over a summer holiday. "It doesn't seem to have a long-term effect on the ovaries or pituitary gland. Those are effectively put to sleep, the same as when a woman is pregnant. Then they bounce back."

The Pill, and Seasonale, work by artificially raising the level of female hormones in the blood. This overrides the normal hormonal signal from the ovaries, and prevents the shedding of the lining of the uterus that is the bleeding seen in menstruation.

Long-term use would be very unlikely to have any harmful side-effects, he adds.