Qlaira: a 'natural' change of direction.

©FSRH J Fam Plann Reprod Health Care 2009: 35(3) Background There is no doubt that the combined oral contraceptive pill (COC) has revolutionised and changed women’s lives for the better. With the discovery of progestogens in the 1940s/1950s, and the realisation that the accidental addition of synthetic estrogen [mestranol – the inactive precursor of ethinylestradiol (EE)] improved bleeding patterns, the contraceptive pill was born. Ever since, work has been ongoing to reduce its dose, its health risks and its side effects. In the last 50 years, doses of synthetic estrogen have fallen from 150 μg mestranol to just 15 μg EE (Mircette® containing desogestrel and Minesse® containing gestodene – neither pill is currently available in the UK). These ‘ultra low-dose pills’ maintain efficacy when modern progestogens are used,1 but the cost is cycle control: only 72% of women report ‘normal cycles’.2 In addition, these pills still produce small changes in lipid metabolism, coagulation factors and glucose regulation.1 Could a ‘new pill’ formulation using 17β-estradiol or one of its esters offer a ‘safer option’?