Non-steroidal anti-inflammatory drugs (NSAIDs) are a type of pain relief medication recommended as a first-line therapy to ease the milder symptoms of endometriosis. There are many different types of NSAIDs of different strengths available either over the counter or with a prescription.

How NSAIDs work

NSAIDs can ease pain by preventing inflammation. Inflammation is a natural immune process, triggered by infection, stress, or damage. It causes swelling, heat, irritation, and further damage.

NSAIDs work by blocking a group of enzymes called cyclooxygenases (COX). These enzymes have several roles in the body, including the production of prostaglandin hormones. Several prostaglandins, such as PGE2, act as part of the immune response to trigger inflammation. By reducing prostaglandin levels, NSAIDs reduce inflammation and stop the resulting pain response.

NSAIDs do not provide immediate relief from pain. They do not reduce existing inflammation and the associated pain, but prevent further inflammatory signals. As a result, NSAIDs should be taken before the pain occurs, for example, 24 hours before a menstrual period.

NSAIDs for endometriosis

Endometriosis is associated with the abnormal growth of endometrial-like tissue outside the uterus forming lesions. In response to hormones, endometrial tissue thickens, breaks down, and exits the body during the monthly menstrual cycle.

The abnormal lesions respond in the same way, thickening and breaking down, but become trapped in the body. This causes inflammation, leading to pain and potential scarring of the surrounding organs. As NSAIDs reduce inflammation, they can help ease endometriosis-associated pain and reduce the risk of scarring.

Prostaglandins can also trigger contractions that help shed the thickened endometrial tissue during a period, causing additional pain. By reducing prostaglandin levels, NSAIDs also reduce this pain associated with the menstrual cycle.

Additional information

There are several types of NSAIDs that act to block different types of COX enzymes; it may take several attempts to find a brand that works best for an individual. Talking to a medical professional can help identify suitable and safe alternatives.

NSAIDs can cause gastrointestinal side effects, as prostaglandins are also involved in maintaining the health of the lining of the stomach. Taking NSAIDs with food or milk may reduce side effects such as upset stomach, nausea, vomiting, diarrhea, and stomach ulcers.

NSAIDs may also have serious side effects, including increased risk of heart attack, stroke, or stomach or intestinal bleeding. Long-term or high-dose use of NSAIDs can increase the risk of these side effects.


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