What is the most effective way to take PrEP? I have some friends that prefer to take it all the time and others that only use it before and after sex - is this method safe?
Both methods are safe - it depends on how far in advance you tend to plan having sex and how regularly you have sex.
Daily PrEP - taking your PreP every day is suitable if you have anal or vaginal sex.
On demand PreP - is when you know that you are going to have sex that could put you at risk of HIV and you start taking PreP 24 hours before this.
I think the best description of PrEP and the pros and cons of the different methods of taking it can be found here. There are clear descriptions and also some useful videos.
If you are interested in PrEP there are still some places available for Heterosexual women on the Impact Trial.
To find a clinic near to you please go to https://www.prepimpacttrial.org.uk/