*Welcome to the OutUK series looking at gay men and their health brought to you in association with the NHS* website.**
	Each week we'll tackle a different topic in our A to Z of Gay Health. We'll have features and advice on everything from relationships, sexual health, mental and physical conditions and how to stay fit. You can follow any of links provided below for more information direct from the NHS website, or view any of our Previous A to Z Features.

You should also know that OutUK has produced a special report about: Coronavirus Covid-19.

This Week - P : PrEP

Pre-Exposure Prophylaxis (PrEP) is used to reduce the risk of getting HIV (human immunodeficiency virus).

PrEP works by stopping HIV from getting into your body and making copies of itself (replicating). You'll only be protected from HIV infection if there are high enough levels of PrEP in your body, so it's important to take it correctly.

PrEP can be used by anyone from a community or group that is most at risk of HIV, or people who have sex with people from those networks.

You may benefit from taking PrEP if:

you're an HIV-negative man having condomless sex with men, and other people who have sex within these networks
you have a partner (or ex-partner) with HIV
your partner (or ex-partner) comes from a country with high rates of HIV
you have condomless sex with a partner(s) and do not know their HIV status
you're a trans or non-binary person and are regularly having condomless sex
you exchange sex for money, drugs, shelter or another reason
you are injecting drugs

Find out more about who is at risk of getting HIV.

Find out more about other at-risk activities.

PrEP comes as tablets that contain 2 medicines called tenofovir disoproxil and emtricitabine. Both medicines are often also used to treat HIV.

You can get PrEP from a health professional at an NHS sexual health clinic.

Key facts

PrEP does not protect you against other sexually transmitted infections (STIs).
Common side effects of PrEP include feeling sick (nausea), diarrhoea, bloating, indigestion, headache, feeling tired or weak and sleeping problems. They usually go away after the first couple of weeks.
If you get stomach side effects while taking PrEP, taking it with or just after food may help.
Most people can take PrEP every day but some people can take it on demand (just before and after sex).
If you take PrEP daily for vaginal/frontal sex, it takes 7 days to give maximum protection. If you take it only when you need it for anal sex, you'll be protected about 2 hours after your first double dose.

How to take PrEP

For PrEP to be most effective, the medicine needs to be at a certain level in your body. As the body takes time to absorb this medicine, PrEP needs to be taken before exposure to HIV and afterwards. Once you start taking PrEP, you need to be tested and monitored regularly for HIV and STIs.

How you take PrEP depends on your circumstances. There are 2 different ways in which you can take it:

Daily Dosing - you take PrEP every day
For receptive anal and insertive anal sex

When you start PrEP, take 2 tablets (double dose) at least 2 hours but no more than 24 hours before sex. This is to make sure that the medicine levels are high enough to be protective before condomless sex. Continue to take 1 tablet a day, every day.

To stop PrEP, take 1 tablet every 24 hours until 2 tablets have been taken after your last sexual exposure.

Event-Based Dosing (EBD) - you take PrEP around the time of sex
For receptive or insertive anal sex and sharing injecting drug equipment

When you start PrEP, take 2 tablets (double dose) at least 2 hours but no more than 24 hours before exposure. This is to make sure that the medicine levels are high enough to be protective before exposure. Continue to take 1 tablet a day, every day.

To stop PrEP, take 1 tablet every 24 hours until 7 tablets have been taken after your last exposure.

More Information

Tips on how to take daily PrEP

Use a pill box - this makes it easy to see whether you have taken or missed a dose. Set a reminder alarm on your phone or use a pill reminder app. Pick a regular time to take your PrEP and try to stick to this each day - link it to a routine task like brushing your teeth.

If you have a break from PrEP and have condomless sex during this time, consider PEP and have a HIV test before you restart PrEP.

Event-based dosing (EBD)

Studies show that EBD is as effective as daily dosing for people having anal sex. EBD is a way of using PrEP only when you are likely to have sex.

EBD is an option for people who:

do not want to take PrEP all the time
only occasionally have sex without condoms
can plan for sex in advance

EBD is not suitable:

If you have hepatitis B - it is very important to know your hepatitis B status before taking PrEP

EBD for sexual episodes over one day

Take 2 tablets (double dose) at least 2 hours but no more than 24 hours before sex. This is to make sure that the medicine levels are high enough to be protective when you have sex. Take a single tablet 24 and 48 hours after the double dose. This is often called "PrEP 2-1-1" or "PrEP on demand".

EBD for sexual episodes over more than one day

Use this schedule if you may have sex several times over a period of time. For example, you are away for a weekend or on holidays.

Take 2 tablets (double dose) at least 2 hours but no more than 24 hours before sex. If you are continuing to have sex, take 1 tablet 24 hours after the double dose. Continue taking 1 tablet every 24 hours for the days you are having sex.

Take 1 tablet for 2 days after last having sex.
Do not miss any doses if you are taking event-based PrEP.

Missed doses and when to take PEP

If you miss some PrEP doses you may need to take post-exposure prophylaxis (PEP) to reduce the risk of becoming HIV positive.

PEP is a 28-day course of medicine that helps reduce your risk of getting HIV after exposure to the virus. If your only exposure has been through oral sex, you will not need to take PEP. This is regardless of how many doses you missed.

OutUK has just begun a series of articles on Sexual Health for Gay Men. This week you can find out about the risks of getting a sexually transmitted infection (STI) from different sexual activities.

We'll have more information and advice next week on another topic in our A to Z of Gay Health. We have covered many subjects in this series and you can catch up with all of our Previous A to Z Features. If you want to find out more about this week's subject you can visit the Original article on the NHS website. If you are worried by any aspect of your health make sure you go and see your doctor or book an appointment at your local clinic.
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