Switching from hormonal contraceptive method to combined hormonal contraception98
| Switch from | Switch to | When to start | Requirement for additional contraceptive precaution | Notes |
| CHC | Another CHC | Start on day after last active COC, CVR or CTP | No | If a hormone-free interval (HFI) is taken the need for additional precautions and emergency contraception should be assessed on an individual basis, taking account of correct use before the HFI. See also Table 7. |
| Traditional POP | CHC | Can be started immediately if the POP has been used consistently and correctly | Yes (7 days*) | The primary mode of action is not inhibition of ovulation and therefore additional precautions are required in case ovulation occurs before contraceptive efficacy of CHC has been established. The cervical mucus effect may be maintained but there is no evidence to prove adequate contraceptive protection. |
Progestogen-only anovulatory methods
| CHC |
| No | The primary mode of action of these methods is inhibition of ovulation. CHC suppresses ovulation by the time the inhibitory effect of the previous method is lost. |
| LNG-IUS (within licensed duration of use) | CHC | Start at any time. | Yes (7 days*)If there has been UPSI in the last 7 days, the LNG-IUS should be retained for 7 days |
CHC, combined hormonal contraception; COC, combined oral contraception; CTP, combined transdermal patch; CVR, combined vaginal ring; LNG-IUS, levonorgestrel-releasing intrauterine system; POP, progestogen-only pill; UPSI, unprotected sexual intercourse.
*9 days estradiol valerate/dienogest pill.