I have been making the claim for many years that the evidence is clear that Plan B emergency contraception is less effective than frequently advertised. When first made available, the manufacturer claimed that Plan B EC was about 90% effective in reducing unwanted pregnancy when taken after unprotected sex. Later on, and very quietly, researchers admitted that the effectiveness is not even close to 90%. In fact, here is the quote from researcher and senior fellow of the Guttmacher Institute James Trussell:
The risk of pregnancy for women requesting ECPs appears to be lower than assumed in theIt turns out that Dr. Trussell was far too optimistic even in this assessment. Now, it turns out that for many women, Plan B EC is not actually better than nothing!
estimates of ECP efficacy, which are consequently likely to be overestimates. Yet, precise estimates of efficacy may not be highly relevant to many women who have had unprotected intercourse, since ECPs are often the only available treatment. A more important consideration for most ECP clients may be the fact that data from both clinical trials and mechanism of action studies clearly show that at least the levonorgestrel regimen of ECPs is more effective than nothing.
The European manufacturer of an emergency contraceptive pill identical to Plan B, also known as the morning-after pill, will warn women that the drug is completely ineffective for women who weigh more than 176 pounds and begins to lose effectiveness in women who weigh more than 165 pounds...
These pills, which use a compound called levonorgestrel to prevent pregnancies, are the most effective morning-after pills available without a prescription. Other pills sold in the United States require a prescription, are less effective at preventing pregnancy, or cause side effects such as nausea or vomiting. Plan B One-Step, which retails for $50, is the only emergency contraceptive drug in the United States available to women of all ages without a prescription.
Emergency contraception advocates reacted to the news about Norlevo with dismay. "There's a whole swath of American women for whom [these pills] are not effective," says James Trussell, a professor of public affairs at Princeton and a senior fellow with the Guttmacher Institute, a think tank for reproductive health issues.
The advocates of Emergency Contraception have been pushing this medication women of all ages without prescription despite the fact that the evidence has been available for quite a while that it was not effective. This is shameful.
Data for the years 2007 to 2010 show the average weight of American women 20 years and older is 166.2 pounds—greater than the weight at which emergency contraceptive pills that use levonorgestrel begin to lose their effectiveness. The average weight of non-Hispanic black women aged 20 to 39 is 186 pounds, well above the weight at which these pills are completely ineffective. A CDC survey published in February found that 5.8 million American women used emergency contraceptive pills from 2006 to 2010.