Here's a clear, evidence-based answer:

Short answer: Generally, NO — the most common pain killers for period cramps (NSAIDs) do not affect your hormones directly.

Drugs like ibuprofen, naproxen, mefenamic acid, and diclofenac are the first-line treatment for period cramps (primary dysmenorrhea). They work by inhibiting prostaglandin synthase (COX enzymes), which reduces the production of prostaglandins — not hormones.

Prostaglandins are local chemical mediators, not reproductive hormones. In the uterus, they cause:

By blocking prostaglandin production, NSAIDs reduce cramping without touching estrogen, progesterone, LH, or FSH — the actual reproductive hormones.

— Goldman-Cecil Medicine, p. 1447

NSAIDs taken occasionally during menstruation do not affect ovulation in the normal use case. However, high doses taken around the time of ovulation (mid-cycle) have been shown in some studies to potentially delay ovulation transiently — but this is not a concern when taken for 2–3 days during your period, as ovulation has already either occurred or is not imminent at that point in the cycle.

If NSAIDs are not enough, doctors may add oral contraceptives (the pill), which do work hormonally — they suppress ovulation and limit prostaglandin release. But that's a separate medication, not the painkiller itself.

— Goldman-Cecil Medicine, p. 1447

Bottom line: Common period pain killers (NSAIDs) target prostaglandins — the chemicals that cause cramping — not your hormonal system. They are safe for short-term use during menstruation and do not disrupt your hormonal cycle.