Even after having reduced their hormonal dosage by 92%, contraceptives would prevent ovulation and thus prevent pregnancy.
- A mathematical model was created to predict the minimum hormonal dose necessary to obtain effective contraception.
- By reducing the dose of estrogen by 92% and the dose of progesterone by 43%, contraceptives still prevent ovulation.
- “It is more effective to administer the estrogen contraceptive in the middle of the follicular phase (which determines the start of the menstrual cycle)”.
“Contraceptives composed of estrogen and/or progesterone are means of preventing pregnancy, which are frequently prescribed”, said researchers from the University of the Philippines. These hormones block ovulation, the phase of the cycle during which an egg is released into the uterus.
Problem: Contraceptive methods containing estrogen and progesterone (pill, patch, vaginal ring, implant, intramuscular injection) can cause several side effects, associated with high doses of hormones, such as weight gain, aches headache, nausea, acne, thrombosis or myocardial infarction. These reactions “make people hesitate to use them”.
Pill: predicting the minimum hormonal dose using a mathematical model
In a recent study, scientists wanted to determine the minimum dose of hormones needed to obtain effective contraception. For this, they created a mathematical model describing the interactions between the different levels of hormones as well as their effects. The team used data from 23 women aged 20 to 34, who had normal menstrual cycles.
“The mathematical model correctly predicts the average daily levels of pituitary hormones and ovarian hormones throughout a normal menstrual cycle and reflects the reduction in these hormone levels caused by estrogen and/or progesterone,” can we read in the works.
A tiny dose of hormones would be enough to prevent ovulation
According to the results, published in the journal Plos Oneit is possible to reduce the dose of estrogen by 92% in contraceptives and decrease the dose of progesterone by 43% while preventing ovulation. “It is most effective to administer the estrogen-based contraceptive in the middle of the follicular phase (which determines the start of the menstrual cycle). Finally, we show that by combining estrogen and progesterone, the dose can be further reduced to provided that the contraceptives are administered during a critical window of the menstrual cycle”, concluded the authors.