Health Canada has asked pharmaceutical companies to include a new warning in emergency contraceptive packages that morning-after pills are less effective for women who are overweight.

The statement from Health Canada was released on Tuesday, March 25. Women who weigh between 165 and 176 pounds are likely to find the post-intercourse contraceptive pills less effective, it said. Additionally, according to the Health Canada statement, women who weigh over 176 pounds will find the pills ineffective.

Women take emergency contraceptives or post-intercourse pills within 72 hours of unprotected sex. The pill is also taken if there is any contraceptive accident list condom breaking. The pill helps prevent pregnancy. According to CTV News, these pills have a much higher dose of the hormone present in regular contraceptive pills. The hormone helps women prevent fertilisation or ovulation. The pills, however, do not work on pregnant women - according to Health Canada document.

At the moment, there is no warning label on the effectiveness of the pills on the basis of weight. However, Health Canada has claimed to have sent letters to drug manufacturers in the country and requested them to update the packaging with warning labels. Health Canada will allow the companies to keep contraceptive packages even without warnings at the moment as this happens to be the transitional phase.

The effectiveness of such emergency contraceptive pills started being evaluated by the federal drug regulator a couple of months back. The concept of the ineffectiveness of these pills on heavier women was originally instigated by a French drug manufacturing company, Laboratoire HRA Pharma, which declared that their pills would not work on heavier women. Its product Norlevo is available in Canada.

HRA Pharma will change the packaging of Norlevo and include the warning labels. However, there are three more emergency contraceptive pills which are available in Canada. Plan B, Option 2 and Next Choice - on the contrary - do not have any warning label attached to their packaging. All of these contraceptives, which are widely available in the market, do not need a prescription.

window.NREUM||(NREUM={});NREUM.info={"beacon":"beacon-2.newrelic.com","licenseKey":"530c5b0e18","applicationID":"2665226","transactionName":"MVEBZBZSD0dZBkJaDggbNkINHANdQkpGXxQBXQ1DS1YFXUwKRBwLFVcRWRRHEhtMDFhKPgtXBh8UXxRTUQtFHBEHRxdVS1ENVVYOGFsVCw==","queueTime":0,"applicationTime":0,"ttGuid":"","agentToken":"","userAttributes":"","errorBeacon":"jserror.newrelic.com","agent":"js-agent.newrelic.com/nr-356.min.js"}

// -->

Read Health Canada's Report HERE.