Analysis by Dr. Joseph MercolaFact Checked

STORY AT-A-GLANCE
- A study in Obstetrics & Gynecology found that those who received COVID-19 shots had longer menstrual cycles, typically by less than one day, when they received the shots
- The longer cycles were noted for both doses of the injection, with a 0.71-day increase after the first dose and 0.91-day increase after the second dose
- Some women experienced even greater menstrual changes, particularly those who received two shots in the same menstrual cycle
- These changes included a two-day increase in cycle length and, in some cases, changes in cycle length of eight days or more
- The study only evaluated menstrual cycle length, which means more research is needed to determine how the shots affect other aspects of menstruation, such as symptoms like pain and mood changes and characteristics of bleeding, such as heaviness of flow