If given within the first 7 days of the menstrual cycle, it becomes effective immediately. However, if CICs are started after the first 7 days of a cycle or the woman is not menstruating, a back-up method is recommended to be used for 7 days. Some providers recommend a back-up method be used for 7 days if Cyclofem or Mesigyna are begun after the fifth day of the cycle. Hypothetically, all CICs are effective when begun within the first 7 days of the menstrual cycle. However, a recent study has demonstrated high contraceptive efficacy for a CIC similar to Cyclofem and Mesigyna when initiated between days 7 and 10 of the menstrual cycle.
Some experts believe that the lower-dose CICs are effective at least as promptly as COCs.
The following rationale is based on what is known about combined oral contraceptives. CICs can be started from the second to the third week postpartum or at the first postpartum menstruation. CICs can be initiated any time within the first-week after an abortion. This should be emphasized when training personnel and counseling clients. The grace period of combined injectable contraceptives is officially 3 days.