What environmental impact can a contraceptive molecule have? Recent work by UNamur researchers answers this question, and has just been published in the journal Environment International. This work is the fruit of a three-year collaboration with Mithra, a Belgian biotech company committed to transforming women’s health with innovative alternatives, particularly in contraception, funded by SPW Research.
Conventional oral contraceptives contain two main components: ethinylestradiol, a synthetic estrogen, and drospirenone, a progestin. For over 30 years, ethinylestradiol has been recognized as an endocrine and environmental disruptor. Studies carried out in the 90s, testing waters upstream and downstream of wastewater treatment plants, showed that downstream fish were predominantly female, attributing these endocrine changes to ethinylestradiol.
In the 1960s, a fourth natural estrogen, estetrol , was discovered in humans, produced by the fetal liver during pregnancy. Identified as an alternative to synthetic estrogen, Mithra acquired a patent for its synthesis and uses it in a new contraceptive pill in combination with drospirenone.
The study aims to assess the environmental impact of esterol , an alternative to ethinyl estradiol , by exposing several generations of zebrafish to environmental doses. Zebrafish , native to India and Malaysia, are commonly used in aquaria and laboratories as model organisms.
" The advantage of zebrafis h is that their life cycle is short: after 3 to 5 months, we already have a new generation of fish capable of reproducing," explains Patrick Kestemont.
The results, demonstrated by validated OECD tests, show that esterol has a significantly lower impact on the environment than ethinylestradiol, even at much higher concentrations. This research is in line with the objectives of the European Greendeal, which requires pharmaceutical companies to pay increasing attention to the environmental impact of their products, whether in terms of formulation, manufacturing processes or residues linked to their use.
These promising initial results were recently presented in Bilbao at the European Society of Contraception and Reproductive Health conference.
