How To Take Intermittent PrEP

Intermittent PrEP  also called “PrEP on demand” is a way to take PrEP medication if you find your level of sexual activity is infrequent, your risk of exposure is only for short periods of time – such as travel, or you have significant side effects from PrEP that make taking daily tablets undesirable. (1)

The iPerGay study showed that short term use of Truvada PrEP can be effective using the following schedule (2) for CIS males who have sex with other men:

  • Take TWO Truvada pills from 24 hours to 2 hours in advance of an anticipated exposure to HIV.
  • If you do have sex that risks exposure, then take another pill 24 hours _after _the first dose and another one the day after that – again 24 hours after the previous pill.
  • If, however, you have sex that risks exposure again at some point in the two days after the first sex – then keep on taking one Truvada pill per day, until two days (48 hours) after your last sex. Only then stop.

The following video helps explain how to take intermittent PrEP using 3 different examples

In A Nutshell:

Take 2 tablets of Truvada 2-24 before sex, then take one tablet every 24h after the first dose till you’ve had 2 days (48h) free from sexual activity.

Time Intervals Between Intermittent Doses

If you have finished your episode of PrEP and then potential sex come up how do you proceed?

  • If it’s less than 7 days since your last tablet you don’t need to take the double starting tablets, just one.
  • If it’s been more than 7 days since the last dose of PrEP you need to start again with the 2 tablets of Truvada

From this point it’s continue as above, one tablet of PrEP every 24 hours till 48 hours has passed free of sex.

Currently on demand PrEP research has looked at gay males only. (3) The Australian PrEP Guidelines note:

It is important to emphasise that on-demand PrEP should not be used in cis-gender women, heterosexual men or trans individuals owing to a lack of data about its efficacy in these populations.


How To Take iPerGay PrEP Video Transcript