A new study suggests that hormone dosages in common birth control pills could be drastically reduced while still being effective in preventing ovulation.
The scientists who conducted the study believe their findings may provide new insights into the complexities of the endocrine system and support the need for more precise and individualized hormonal birth control could benefit many people.
Mathematician Brenda Lyn A. Gavina of the University of the Philippines Diliman and colleagues from the Philippines, Korea, the US and Denmark constructed mathematical computer models to study the optimal timing and dosing of hormonal contraceptives to determine the dosing – and therefore the potential – to identify side effects – could be reduced.
The endocrine system regulates and influences the progression of a human menstrual cycle through multiple stages by secreting hormones from the hypothalamus, pituitary and ovaries.
To learn more about how these hormones interact, Gavina and her team collected information on pituitary and ovarian hormone levels from 23 healthy women between the ages of 20 and 34, all of whom reported regular menstrual cycles lasting between 25 and 35 days and had shown signs of ovulation in the last cycle.
Researchers used this real-world data to create a mathematical model of the normal menstrual cycle, which allowed them to predict daily hormone levels during a normal menstrual cycle and study the effects of exogenous hormone administration on these levels.
The most common birth control methods – pills, injections and implants – introduce one or both of the synthetic hormones estrogen and progesterone into the bloodstream to prevent pregnancy.
Synthetic hormonal contraceptives block ovulation, prevent egg release and fertilization, and alter cervical mucus to obstruct sperm and prevent egg implantation.
The modeling was able to make predictions not only about the minimum dose of these hormones needed for contraception, but also the effects of the combination of estrogen and progesterone and the optimal timing of doses.
“Numerous previous modeling studies have examined the menstrual cycle, how it occurs and how it can be modified,” the authors said write in their published work.
“To our knowledge, our work is the first to use modeling to study the timing of dosing, thereby further minimizing dose.”
The method used in modeling, known as Optimal Control Theory, is certainly not new. Previous research has used it to show how treatment protocols work diabetes And prostate cancer could be optimized and, according to the study authors, to describe the optimal hormone dosage for in vitro fertilization (IVF).
Now the team thinks the same approach could be used to optimize dosing of hormonal contraceptives. However, they note that their model does not account for the variation in cycle length, which varies within and between people.
The modeling suggests that birth control pills could work effectively with far lower doses of estrogen or progesterone than those currently prescribed, and that taking hormones at certain times during the menstrual cycle may be more effective than taking them all the time.
“The results show that it is possible to reduce the total dose by 92 percent with estrogen-only therapy and 43 percent with progesterone-only therapy,” writes the team“and that it is most effective to administer the estrogen contraceptive in the mid-follicular phase.”
And when both hormones are taken in combination, they found that even lower doses of each hormone could be enough to prevent pregnancy.
“Finally, we show that the dose can be reduced even further by combining estrogen and progesterone,” the team said adds.
Ovulation suppression is not only helpful for birth control; it can help unpleasant, disturbingand sometimes downright painful menstrual cramps and, perhaps surprisingly, reduce the risk of injury to the anterior cruciate ligament (ACL).
Even if we have been using hormonal contraceptives for decades, the full Effects are still poorly understood.
“Despite many advantages”, Gavina and team write“Undesirable side effects associated with high doses, such as thrombosis and myocardial infarction, lead to hesitancy in use.”
Of course, it would be ideal if everyone shared the responsibility for contraception, and we are search for solutionsincluding further non-hormonal avenues, though they are turns out to be complex.
At the same time, research continues to improve current contraceptives sorely neededin view of her serious side effects.
“The results of this study have the potential to bring contraceptive access to more women,” the researchers said say“especially since lower doses also reduce the risk of unwanted side effects.”
While this work remains a modeling exercise for now, it highlights the benefits of ongoing research to improve commonly used contraceptives.
The peer-reviewed study was published in PLOS Computational Biology.
