Answer
Yes, oral norethisterone is partly converted into ethinylestradiol, equivalent to about 4–6 micrograms of ethinylestradiol per 1 milligram of orally administered norethisterone or norethisterone acetate.
Sources for this answer
- Primolut NBayer plc · emc · SmPC §4.4 Special warnings and precautions for use · Version 15Document updated
Sources checked