One key factor when choosing a method of birth control is how effective it’s going to be. You can read the effectiveness of each method here – ‘We’ve ranked all methods of birth control by their effectiveness’.

If you’re using birth control to prevent pregnancy, then it’s really important to understand how effective it is at doing that. However, how do you know? There are a few ways that doctor’s talk about effectiveness:

  • Perfect Use –  This indicates failure rate if you would use the birth control perfectly. That means no condom mishaps, you always take the pill at exactly the same time every day, day in, day out, for example.
  • Typical Use – For those of us who are human, this is a better figure to look at – it takes into account, failure rate of the contraception if you forget to take the pill, or if the condom breaks, for example. Which can happen to all of us (and certainly does!).
  • The Pearl Index – defined as the number of contraceptive failures per 100 women-years of exposure, and uses as the denominator the total months or cycles of exposure from the initiation of the product to the end of the study or the discontinuation of the product. (Read more here).

And because you need to know this stuff, here’s a song from the fabulous Dr Dervaitis (whose You Tube channel should be on your subscribe list!), & whose Instagram feed you should be liking (along with ours, obviously!). What better way to understand this important difference with a song!

Here at Four Five Oh, we tend to use the Perfect and Typical use indicators for effectiveness, since we think it’s easier to understand, and it highlights the importance of making sure you know how to use the method correctly. Note also that methods administrated by medical professionals, such as the IUDs Kyleena, Mirena, Jaydess, the contraceptive implant Implanon, have the same typical and perfect use (as long as you remember to get them replaced on time!).

Are you using any of these birth control methods? If yes, we’d love to hear from you!If you’d like to be featured in our Real Women | Real Experiences series, please contact us at

If you’d like to share your own experience and tell us what side effects you felt, and whether you recommend any of these methods to others, head over to Share your Experience