What happens if access to PrEP is interrupted? What if I stop taking PrEP and then start taking it again later?

If a daily dose is missed, PrEP is still effective but the level of HIV protection may decrease. It only works if you take it correctly and consistently.
According to data analysis from the iPrEx study that found PrEP to be effective:

  • For people who take 7 PrEP pills per week, their estimated level of protection is 99%.
  • For people who take 4 PrEP pills per week, their estimated level of protection is 96%.
  • For people who take 2 PrEP pills per week, their estimated level of protection is 76%.

There are not enough data available to provide specific timing guidance on non-daily use, so the FDA recommends PrEP be used daily to achieve the highest level of protection.