A consumer advocacy group petitioned the U.S. Food and Drug Administration on Thursday for the removal of a Johnson and Johnson transdermal birth control patch from the market due to increased risk of dangerous blood clots.

The bird control patch involved, Ortho-Evra, is marketed in the U.S. by Ortho-McNeil, a pharmaceutical manufacturer based in Raritan, New Jersey, and a subsidiary of Johnson & Johnson. When applied to the skin, the patch releases synthetic estrogen and progestin hormones to prevent pregnancy. The patch is applied (changed) weekly for three weeks in a row, then one week is skipped.

Ortho-Evra became controversial after an AP investigation in 2005 showing that women using it suffer higher rates of life-threatening blood clots than women taking birth-control pills.

In fact, the FDA has already added a warning label on the patch as recently as January, saying that women who wear the patch have about double the risk of developing blood clots.

According to Public Citizen’s Health Research Group, the amount of estrogen released from the Ortho-Evra patch varies widely among individual women and those who absorb too much were at greater risk for blood clots and other painful side effects, said Sidney Wolfe, head of the research group, Reuters reports. Women who use Ortho Evra can be exposed to about 60 percent more estrogen than pill users.

Moreover, patch use doesn’t result in any improvement in contraceptive outcomes when compared to the oral contraceptives.

Spokeswoman for Ortho Women's Health and Urology, (the J & J unit that makes the product) Gloria Vanderham said the risks of the patch as well as its benefits are already underlined on the product’s label. However, women should never use any contraceptive without the doctor’s approval, especially if they are smokers, having high blood pressure or having a family history of blood clots. The risk is even higher in their case.

However risky or not, sales of the patch in the U.S. totaled $153 million in 2007, according to data from health care information company IMS Health.