More than 47,000 members of MyLupusTeam take hydroxychloroquine (also known as HCQ and sold under brand names such as Plaquenil), an antimalarial that’s also used to manage lupus. Like all drugs, HCQ can bring on a range of side effects, and some members have wondered if taking it affects periods.

“Has anyone experienced wacky menstrual cycles when starting Plaquenil?” one member asked. “I just started taking it on Tuesday, and my period should be here and it isn’t.”

There isn’t much research on this topic, making it difficult to give a definitive answer regarding HCQ’s effect on menstrual periods. In this article, we’ll explore what evidence shows, consider experiences described by members, and discuss other potential causes of menstrual cycle changes in people who have lupus.

Hydroxychloroquine and the Treatment of Lupus

HCQ is used to treat and prevent malaria, and it’s also prescribed to treat autoimmune diseases like systemic lupus erythematosus (SLE) and rheumatoid arthritis. HCQ helps reduce inflammation and manage lupus symptoms.

HCQ comes with a lengthy list of side effects, most commonly nausea, diarrhea, and stomach cramps. In rare cases, the drug can cause more serious problems, such as vision changes. However, adverse reactions discussed on the drug’s prescribing information do not include menstrual cycle changes, and more research is needed to determine if HCQ affects periods.

Meanwhile, some MyLupusTeam members have discussed their experiences with HCQ and linked the drug to irregular periods. They’ve shared comments such as these:

• “I started taking Plaquenil two months ago, and I’ve had three bizarre periods since then. It’s unusual for me, since my periods have always been regular. I’m currently on day 12 of nonstop bleeding, and my last two periods were back to back, only one week apart.”
• “I just started Plaquenil a few weeks ago, and my period has come nine days early — normally it’s 28 days on the dot.”

Others report no effect of the drug on menstrual changes: “I take Plaquenil, and my menstrual cycles are on point.”

How Hydroxychloroquine Could Affect Your Menstrual Cycle

One lupus symptom that HCQ helps treat is abnormal blood clotting — specifically, it helps prevent your blood from clotting too much. This can lead to unusual bleeding, a potential side effect. You may bleed more than usual as your body sheds the lining of your uterus. Although this issue hasn’t been studied in people taking HCQ, a 2022 study found that people taking blood thinners, another category of medications, experienced heavier periods.

Hydroxychloroquine May Help Prevent Endometriosis

HCQ may help prevent a condition called endometriosis, which occurs when the endometrium (tissue that lines the uterus) is located outside the uterus. Endometrium may be found on organs like the ovaries or fallopian tubes. Normally, the uterine lining thickens and sheds during the menstrual cycle. With endometriosis, the misplaced tissue also responds to hormones and bleeds, causing pain and inflammation. This can lead to symptoms like severe pain, painful periods, pain during sex, and trouble getting pregnant. The exact cause of endometriosis is not fully understood, but it could be due to hormones, genetics, or the backward flow of menstrual blood — or a combination of factors.

People with lupus have an increased risk of developing endometriosis. A 2021 study found that using HCQ lowered the risk of endometriosis in people with lupus. This might be because HCQ helps reduce lupus activity, which may prevent the lupus symptoms that can contribute to the development of endometriosis. Again, more research is needed to clarify the connections.

Other Lupus Medications and the Menstrual Cycle

Although HCQ hasn’t been shown to affect the menstrual cycle, other medications that treat lupus might. If you begin taking one of these drugs along with HCQ, it might seem like the HCQ interfered with your period. Medications that could cause abnormal periods include:

• Corticosteroids — Corticosteroids such as prednisone help reduce inflammation caused by lupus. However, long-term use of corticosteroids can affect your hormones and cause irregular or missed periods.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) — NSAIDs like ibuprofen or naproxen are often used to manage pain and inflammation in lupus. NSAIDs can potentially reduce heavy menstrual bleeding. If your period is light, NSAIDs may cause it to go away entirely.
• Immunosuppressants — Medications such as cyclophosphamide (Cytoxan), mycophenolate mofetil (CellCept), and methotrexate (Rheumatrex) are prescribed to dampen your immune system and reduce lupus activity. These drugs may affect your menstrual cycle by causing you to skip a period or even stop menstruating.

Not everyone will experience menstrual changes while taking these medications. Talk with your rheumatologist if you have concerns about how your lupus medications might be affecting your menstrual cycle. They can provide guidance based on your treatment plan and your lupus symptoms.

Other Causes of Irregular Menstrual Cycles

Menstrual cycle irregularities can occur in people with lupus, regardless of whether you take HCQ. Lupus causes inflammation and other physical changes that affect the menstrual cycle. For example, lupus is often associated with menorrhagia — extremely heavy bleeding during periods. Likewise, hormonal changes during the menstrual cycle could trigger a lupus flare.

Birth Control Medications

Using birth control can affect your period in several ways. Different types of hormonal contraception, like the pill, patches, injections, intrauterine devices, and implants, work by changing the hormones in your body. These hormonal changes can help regulate your menstrual cycle, making it lighter, shorter, or more predictable. Some types of birth control can even help ease menstrual symptoms like painful cramps or heavy bleeding.

However, certain forms of birth control may cause irregular bleeding or spotting between periods, especially when you first start to take them. Keep in mind that everyone’s body responds differently to birth control, so changes to your period may vary. If you have any concerns about how birth control is affecting your period, talk with your health care provider. They can provide guidance on the best birth control option for you.

Stress

Stress can affect your menstrual cycle, especially when you’re dealing with the challenges of living with lupus or starting a new medication. When you’re stressed, your body makes more cortisol, a hormone that helps your body handle stress. High cortisol levels can disrupt the hormones that regulate your menstrual cycle. It’s important to understand the link between stress and your period and find ways to calm yourself down. Taking time for yourself, practicing relaxation techniques, and seeking support from loved ones can all help reduce stress and potentially help regulate your menstrual cycle.

Pregnancy and Breastfeeding

When you’re pregnant, you will most likely not have a period. After giving birth, it may take a while for your period to come back. You may not have a period if you’re breastfeeding because prolactin, the hormone that controls milk production, prevents ovulation (the release of an egg from your ovaries). It’s important to know that breastfeeding is not a foolproof method of birth control, and it’s possible to become pregnant even if you haven’t had a period yet.

Menopause

If your periods become less frequent, you may be entering menopause. Menopause is a natural process that occurs as people who menstruate grow older. It typically happens between ages 45 and 55, but the timing can vary. During menopause, your body goes through changes, and you stop having periods. This happens because your ovaries make fewer hormones, like estrogen and progesterone, which are important for controlling your menstrual cycle. Menopause can cause symptoms such as:

• Hot flashes
• Night sweats
• Mood swings
• Trouble sleeping
• Vaginal dryness
• Changes in sex drive

Before menopause is reached, perimenopause occurs. During this transitional phase, your ovaries produce fewer hormones. Because your hormones are no longer stable, you may experience irregular or abnormal periods. During perimenopause, you may also begin to experience menopausal symptoms.

Lupus can cause inflammation and damage to the ovaries, and certain medications like corticosteroids and cyclophosphamide can also affect how your ovaries work. This can lead to irregularities in the menstrual cycle and, in some cases, early menopause.

When To Talk to Your Doctor

Menstrual cycles are different for everyone, but if you feel that something is not right or if your periods are causing significant discomfort, seek medical advice. Your doctor can evaluate your symptoms, identify what’s causing them, and provide options to help regulate your menstrual cycle and improve your symptoms.

Talk With Others Who Understand

MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 223,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus.

Are you taking hydroxychloroquine to treat your lupus symptoms? Have you found that it affects your period? Share your experience in the comments below, or start a conversation by posting on your Activities page.