What do systematic reviews say?

Naproxen vs placebo

Naproxen showed no clear difference in side effects: gastrointestinal symptoms compared with placebo (low certainty).

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  OR 2.11 [0.18, 25.17]
  1 study · 33 participants
  Low