Materials on this web site are protected by copyright law. Access to the materials on this web site for the sole purpose of personal educational and research use only. Where appropriate a single print out of a reasonable proportion of these materials may be made for personal education, research and private study. Materials should not be further copied, photocopied or reproduced, or distributed in electronic form. Any unauthorised use or distribution for commercial purposes is expressly forbidden. Any other unauthorised use or distribution of the materials may constitute an infringement of ClinRisk Ltd's copyright and may lead to legal action.
The monthly regimen of 21 active pills containing estrogen and progestogen, followed by a seven-day break of no pills (or seven placebo tablets) was created to promote a monthly withdrawal bleed and so mimic the menstrual cycle. Continuous use of COCs reduces the number of monthly bleeds. Various formulations are being researched which vary the number of days of use. Seasonale was approved for use in the US in 2009 and is taken continuously for three months (84 days). It is not known when or if similar products will be available in the UK.