Norethindrone (Priming)

Norethindrone is a synthetic progestin sometimes prescribed for 7–14 days before an IVF stimulation cycle begins. It suppresses spontaneous ovulation and prevents a premature LH surge, allowing your clinic to plan an exact start date.

It is often used as an alternative to oral contraceptive pills for cycle scheduling, particularly in patients who respond poorly to estrogen-containing pills.

Once norethindrone is stopped, FSH injections typically begin 2–5 days later. Some research suggests it may improve synchronization of follicle cohorts.