In a comparison study of the effectiveness of different contraceptives in the UK, the below table shows that the contraceptive pill in all forms available are of equal effectiveness:
| Percentage of women experiencing an unintended pregnancy within the first year of use | ||
| Typical use | Perfect use | |
| Combined oral contraceptives’ | 9% | 0.3% |
| Progesterone-only pill | 9% | 0.3% |
The above information has been taken from NICE (National Institute for Health and Care Excellence). View the full assessment here. [link https://cks.nice.org.uk/topics/contraception-assessment/background-information/comparative-effectiveness-of-contraceptive-methods/]