wondering if the COVID vaccine will affect her periodShare on Pinterest
Luis Alvarez/Getty Images

COVID-19 is a disease that’s caused by the novel coronavirus, SARS-CoV-2. It’s often associated with respiratory symptoms, such as cough and shortness of breath. However, COVID-19 can also impact other parts of the body. Digestive, neurological, and cardiovascular symptoms can also occur.

There’s some evidence, through both research and anecdotal reports, that COVID-19 may also affect your period.

Let’s break down what we know so far.

Throughout the pandemic, there have been various anecdotal reports about how COVID-19 may impact the menstrual cycle. Some of the reported changes have included:

So far, little research has been done on the effect of COVID-19 on menstrual cycles. It’s possible that the infection itself could stress your body or disrupt hormone levels, leading to noticeable changes in your period.

A 2020 study found that the lining of the uterus (endometrium) is likely safe from direct infection by the novel coronavirus. This is because it has lower levels of ACE2, the receptor that the novel coronavirus binds to, throughout the menstrual cycle.

So, what do we know about COVID-19 and menstruation? A 2021 study assessed data from 177 menstruating people with COVID-19. Let’s take a closer look at the results.

Insights into COVID-19 and menstruation

Changes in menstrual volume were found in 45 out of 177 people (25 percent). Out of these 45 individuals, 36 experienced a significantly lighter period while 9 had a significantly heavier period.

People with severe COVID-19 were more likely to have a menstrual cycle that was longer than 37 days. Researchers found that 34 percent of people with severe illness had long cycles, compared to 19 percent of people with mild illness.

When researchers compared menstrual cycle length during COVID-19 to an individual’s normal cycle length, they found that 50 out of 177 people (28 percent) had changes in their menstrual cycle. Most experienced a longer-than-normal cycle during their illness, although some had a shorter cycle.

The levels of sex hormones, such as follicle-stimulating hormone, estrogen, and progesterone, from 91 people with COVID-19 were compared to 91 people without COVID-19. No difference was found between the two groups.

Lastly, researchers observed that 84 percent and 99 percent of participants had returned to their normal menstrual volume and cycle length, respectively, 1 to 2 months after having COVID-19.


To summarize the findings of the study:

  • Some people may experience temporary changes in menstrual volume and menstrual cycle length due to COVID-19.
  • The most commonly observed changes were lighter-than-normal periods and increased menstrual cycle length.
  • Levels of sex hormones didn’t differ significantly between those with COVID-19 and those without COVID-19.
  • Most people returned to their normal menstrual patterns 1 to 2 months after having COVID-19.

Read this for a detailed list of COVID-19 symptoms and comparison to other illnesses.

COVID-19 vaccination has also been associated with changes in menstruation. However, research hasn’t directly linked these changes to the COVID-19 vaccines. In fact, research into the way vaccines can impact menstruation is generally lacking.

So far, reports are anecdotal and most often describe irregular periods or heavier periods after vaccination. These effects appear to be temporary, with most experiencing a return to normal menstrual patterns in the weeks after vaccination.

However, According to the UK’s Medicines and Healthcare Products Regulatory Agency (MHRA), the agency tasked with ensuring the safety of medicines, medical devices, and blood products in the UK, between December 8, 2020 and September 8, 2021 there were 34,633 incidents of menstrual and vaginal bleeding reactions reported to them in relation to a COVID-19 vaccine in Great Britain.

To put this in perspective, there were approximately 47.8 million COVID-19 vaccine doses administered to women in the UK during that same time period.

These reports include episodes of:

These effects were more reports from people who’d had the Pfizer-BioNTech vaccine and the AstraZeneca vaccine (which is not authorized for use in the U.S.) than the Moderna vaccine. The MHRA did not report data regarding the Johnson & Johnson’s Janssen COVID-19 Vaccine.

The MHRA concluded that the number of reports of menstrual disorders and vaginal bleeding is low compared to the number of people who menstruate and who have had a COVID-19 vaccine and compared to how common menstrual disorders are among this population in general. They also noted there’s no evidence to suggest COVID-19 vaccines affect fertility.

A September 2021 editorial in the BMJ suggests it’s possible that there may be a link between menstrual cycle changes and COVID-19 vaccines and recommends further investigation.

The author notes that the way the MHRA collects data makes it difficult to draw clinical conclusions. Since menstrual changes have been reported after both types of COVID-19 vaccines, the author suggests that, if there is a connection, it may be related to the body’s immune response to vaccination in general rather than an ingredient or component of these vaccines.

The good news is, more research is planned. In 2021, the U.S. National Institutes of Health (NIH) awarded a total of $1.67 million to five institutions to study the potential link between COVID-19 vaccination and menstrual changes.

It’s also important to remember that there are many other factors that can impact menstruation.

Are there side effects after the COVID-19 vaccine?

It’s possible that you’ll experience the following side effects after receiving the COVID-19 vaccine:

  • pain, redness, or swelling at the injection site
  • fatigue
  • aches and pains
  • headache
  • fever
  • chills
  • nausea

The Pfizer-BioNTech and Moderna vaccines require two doses for full immunity. The side effects listed above are typically more intense after the second dose. This is normal and is a sign that your body is building immunity.

One less common side effect of the COVID-19 vaccines is a severe allergic reaction. This typically happens shortly after receiving the vaccine, which is why you’ll be monitored for a short period of time after getting your vaccination.

Serious blood clots are a very rare side effect of the Johnson and Johnson vaccine. These may happen in the weeks after vaccination and, according to reports, mainly impact women under age 50. According to an analysis by the CDC and FDA, the likelihood of having this side effect is very low.

Was this helpful?

Menstrual irregularities are estimated to impact between 5 to 35.6 percent of those who menstruate, depending on factors such as age and location. These irregularities can include things like:

Many conditions, illnesses, or medications can also cause your period to be different. Let’s take a quick look at some of the potential changes and their causes.

Irregular periods

Irregular periods refer to situations where your menstrual cycle is shorter or longer than normal. Irregular periods are generally (but not always) light and can be caused by:

Heavy periods

According to the Office on Women’s Health, heavy periods affect about 1 in 5 women in the United States each year. Some potential causes are:

Missing periods

Missing periods are called amenorrhea. You’re typically said to have amenorrhea if you haven’t had a period for 3 consecutive months. Some things that can cause this include:

If you’ve been noticing changes in your period lately, it could be down to pandemic stress. Indeed, there are many pandemic-related factors that can contribute to increased stress levels, such as concerns about:

  • your personal health and the health of your loved ones
  • social isolation related to physical distancing or quarantine
  • finding childcare or helping children with remote learning
  • maintaining a job
  • maintaining weight
  • increased drinking or smoking

Above, we discuss how increased stress may lead to irregular, light, or missed periods. Research has supported this.

A 2015 study found that high stress levels were associated with irregular periods in students. A 2018 study, also in students, found that high stress was correlated with missed periods, painful periods, and premenstrual syndrome (PMS).

Early results from a study of elite athletes found that 1 in 5 noticed changes in their menstrual cycle during the pandemic. While some of these are likely due to changes in training frequency and intensity, the researchers believe that psychological factors like increased stress also played a role.

Who can you ask if you think your period is different because of COVID-19 or the COVID-19 vaccination?

If you notice that your period is different due to having COVID-19 or receiving the COVID-19 vaccine, it’s important not to panic. It’s likely that your normal menstrual patterns will return in the coming weeks.

However, if menstrual changes don’t go away, there are various resources that you can turn to for help. These include:

Additionally, Dr. Kathryn Clancy, a researcher at the University of Illinois at Urbana-Champaign is interested in how COVID-19 vaccination impacts menstruation. You can participate in her secure online survey here.

Was this helpful?

It’s possible that having COVID-19 may temporarily affect your period. The exact reason why this happens is currently unknown. Research has found that the most common effects are light periods or longer menstrual cycles.

Receiving the COVID-19 vaccine may also cause changes in your period. These can include things like heavy periods or painful periods. However, scientific data has yet to link these changes directly with the current COVID-19 vaccines.

Remember that many conditions can cause menstrual irregularities. Stress, both physical and psychological, can also play a big role. Be sure to see a healthcare professional or OB-GYN if you have concerns about your period and COVID-19.