Vaccination against Covid-19 would influence the menstrual cycle according to a new study. The results show that it is lengthened by one day on average.
- The menstrual cycle is between the first day of menstruation and the first day of the next menstrual period.
- Menstrual cycles usually last between 24 and 38 days.
- According to the MSD Manual, only 10-15% of women have a cycle that lasts exactly 28 days.
79.1% of the population received a complete primary vaccination against Covid-19 and 59.9% a booster vaccination, according to Public health France. Among the vaccinated, many vaccinated! And, for several months, some of them have been talking about disturbances in their menstrual cycle when they received their injections.
Longer periods of one to three days
Researchers therefore wanted to quantify this disruption of the menstrual cycle. Thus, they studied the data of more than 20,000 women inhabitants in various regions of the world. Result: they affirm that the vaccine modifies the duration of the rules. Their results were published in the journal British Medical Journal.
In detail, the scientists found that the length of the menstrual cycle was increased by approximately one day, compared to the length of menstruation before vaccination. And the disruption was even greater after two doses of vaccine when the injections had taken place during the same menstrual cycle: on average, about three more days.
A temporary disruption of the menstrual cycle
But the authors reassure: this disruption of the menstrual cycle does not last. The vast majority of women return to a normal menstruation period from the next cycle. Thus, the researchers believe that this is one of the side effects of vaccination that women should be informed of before vaccinating them.
If this study has confirmed the link between longer periods and the vaccine against Covid-19, scientists have not yet found the cause. Maybe in a future study?