Recent research has found that women who receive the COVID-19 vaccine may experience temporary changes to their menstrual cycle length and increased symptoms associated with their period. The effects were more pronounced in those who received two doses of the vaccine within the same cycle, with their cycle length increasing by an average of 3.7 days. It is unclear what the effects of a COVID-19 infection are on menstrual cycles, although some studies have suggested a low percentage of people may experience a change in cycle length.
While the effects of the vaccine and infection on fertility and reproductive health are uncertain, research suggests that the benefits of getting vaccinated, such as a decreased chance of hospitalization and critical care admissions, outweigh the risks. The cycle length of those who get the vaccine typically returns to normal after one or two cycles.
To improve understanding of how the vaccine affects both men’s and women’s bodies and reproductive health, more research with larger sample sizes is needed. This research will help inform the public of the potential risks and benefits associated with the COVID-19 vaccine.