New study shows how the vaccine can mess with your period

Photo credit: Andriy Onufriyenko - Getty Images
Photo credit: Andriy Onufriyenko - Getty Images

Earlier this year we reported that a study had confirmed what many of us had long suspected – that getting vaccinated against COVID-19 can have an impact on your period, either causing it to arrive late, last longer or feel heavier/more painful. Thankfully, the side effects are short-lived, and now further research has found that your regularly scheduled period should resume after one menstrual cycle.

This latest research from the Department of Obstetrics and Gynecology, Oregon Health & Science University, published on Tuesday (27 September), uses a wide sample pool of almost 20,000 people (around 75% of whom have been vaccinated and 25% who have not). According to the British Medical Journal, it solidifies and provides sturdy evidence that cycles are altered post-jab and identified that these changes occur irrespective of which pharmaceutical company produced the vaccine a person received (e.g. Pfizer, AstraZeneca, Moderna).

As for how long people's cycles are increasing for, the new research suggests by 0.71 days following the first dose and 0.56 days after the second dose. For those who had multiple coronavirus-related jabs within the same menstrual cycle, the delay leapt up to four days.

Photo credit: Paper Boat Creative - Getty Images
Photo credit: Paper Boat Creative - Getty Images

Speaking about the phenomenon of the jab altering periods, back in January Dr Victoria Male, an expert in menstruation from Imperial College London, said the research is "reassuring", according to the BBC. "Changes to the menstrual cycle do occur following vaccination – but they are small compared with natural variation and quickly reverse," she explained. "[Concerns around fertility being impacted have arisen only] from misinformation that Covid-19 vaccines cause female infertility."

Earlier this year, one US-based study harvested data from close to 4,000 women who use a cycle-tracking app and found that on average, their period was delayed by half a day after their second dose, but there was no delay after the first. This came after more than 36,000 people reporting post-vaccine period irregularities to the MHRA Yellow Card scheme.

Another research project from Norway (of over 5,600 people) reinforced how much periods can also vary naturally – due to an array of reasons from diet changes, to stress. Nearly 40% of study participants reported at least one change to their period, even before being vaccinated, the most commonly noted change being heavier than normal bleeding.

The study said that "menstrual disturbances were generally common regardless of vaccination" but that there was a "significant increase in menstrual disturbances after vaccination, particularly for heavier bleeding than usual, longer duration and for short interval between menstruations."

Anecdotally, others have reported that their period felt heavier and more painful for the first cycle after they contracted COVID-19.

This article is not intended to be a substitute for professional medical advice or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

You Might Also Like