Of all the methods available for reducing risk of pregnancy, most contraceptives contain hormones – including the contraceptive pill, the IUS ‘coil’ (or intrauterine system), and the implant. But what if these methods could be introducing lower levels of hormones into our bodies?
A computational model has calculated that hormone levels in common contraceptives could be reduced by 92 per cent and still be effective at suppressing ovulation.
The results of the study could help clinicians with "optimal dosing formulations and schedule of therapy", according to PhD researcher Brenda Lyn A. Gavina, PhD student at the University of the Philippines Diliman.
Lower levels of exogenous hormones (those introduced to the body externally) could lower some of the risks and side effects associated with high doses of hormonal contraception, including changes in mood and thrombosis.
Ovulation is the point in the menstrual cycle when the ovaries release an egg. If no egg is released, it is not possible for it to be fertilised – and therefore for the woman to become pregnant.
While 92 per cent of hormones could be reduced in oestrogen-only contraceptives, the study also found that progesterone-only contraceptives could be reduced by 43 per cent. And if you combine the two hormones (such as in the combined pill), a dose of each could be even lower.
The results were released today in PLOS Computational Biology by researchers from the Philippines, Denmark, the Republic of Korea and the USA. The team used the computational model to test the interaction between varying hormone levels within the body with varying levels of exogenous hormones.
The study analysed the hormone levels of 23 women between the ages of 20 to 34 with normal menstrual cycles.
The model also indicates that the doses of hormonal contraceptives could be reduced in frequency as only certain phases of the menstrual cycle are important. This would reduce the need for constant doses and lower the overall levels of exogenous hormones in the body.
The model provides evidence that such reduction is possible while still suppressing ovulation – a possible stimulant for further research into lower-dose contraceptives. The research team hope that it will help clinicians to develop better dosing strategies.
Hormonal birth control has recently come under fire with the news that progesterone use can increase risk of breast cancer by up to 30 per cent – though women were encouraged to speak to their doctors to discuss their own risk level.
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