Sex may help with period cramps for some people, but it is not considered a standard treatment. The relief is most likely linked to orgasm, which can release natural pain-relieving chemicals and may temporarily increase pain tolerance.
This effect has not been well studied specifically for menstrual cramps, so it should not be relied on as the main way to manage period pain. Current guidance for period cramps more commonly recommends options such as heat, gentle exercise, massage, NSAIDs, and hormonal birth control when appropriate.
Sex during a period is generally a personal choice. It may feel comfortable for some people and uncomfortable for others. If cramps are related to conditions such as endometriosis, sex or orgasm may worsen pelvic pain instead of relieving it.
A gynecologist should be consulted if cramps are severe, getting worse, new, or interfering with daily activities. Pain during sex, heavy bleeding, fever, or unusual discharge should also be evaluated. Avoid self-medicating frequently without medical guidance.