How soon should i start taking naproxen 500mg for it to stop my period cramps &is it more effective than naprogesic?

Naprosyn (naproxen): is an excellent anti-cramping medication. 500mg is a large dose and should be used inly AM/PM on a full stomach, unless directed otherwise by your GYN

When cramping begins: Without a prescription, the highest dose of naproxen is 200 mg every 8 hours with food when cramps begin; no more than 600 mg per day. Under a doctor’s supervision, the dose may go to 500 mg every 12 hours (or 250 mg every 6-8 hours if stomach upset), with a max of 1,000 mg/day. Naprogesic is not much different, as it contains a form of naproxen - just be aware of the dose.