[2] Even norethindrone, a first generation progestin ... Generations are not standardized, and one compound may appear in different groups. Most of the available OCs contain derivatives of 19 ...

Norethindrone acetate 5mg; scored tabs. Initially 5mg daily for 2 weeks, then increase by 2.5mg/day every 2 weeks up to 15mg/day maintenance dose. Continue for 6–9 months unless breakthrough ...