PrEP (pre-exposure prophylaxis)

PrEP is a tablet you take daily or ‘on demand’ (when you have sex) to stay protected from HIV. When taken daily and correctly, it can reduce your risk of getting HIV from sex by about 99%.

PrEP is a type of medication called an antiretroviral. These medications work by reducing the amount of HIV in the body to a very low level or removing it completely. ‘PrE’ stands for ‘Pre-Exposure’ because PrEP is only effective if it is taken before exposure to HIV. The other ‘P’ stands for ‘Prophylaxis’, meaning a treatment or action you take to prevent an infection or disease. Simply put, PrEP protects you from HIV before you contract it.

What does pre-exposure prophylaxis mean?

‘Pre-exposure’ means ‘before coming into contact with’ something, in this case, HIV. ‘Prophylaxis’ is a treatment that protects you from getting an infection. So pre-exposure prophylaxis means taking a treatment to protect yourself from HIV before coming into contact with the virus. Think of it as a proactive way to significantly reduce your risk of an HIV infection.

PrEP works to prevent HIV by blocking the enzyme that HIV needs to replicate, stopping it from spreading and multiplying. This approach can stop you from developing an HIV infection in the first place.

Tenofovir and emtricitabine are antiviral medications known as nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs). They prevent HIV if it gets into your body by stopping the virus from multiplying.

You should take PrEP if you are HIV-negative and at risk of being exposed to or catching HIV.

People most at risk (but are not limited to) include:

• men, non-binary people, and transwomen who have sex with men and do not always use condoms
• people who are HIV-negative but whose partner is HIV positive
• people who have sex with people from places where HIV is common
• black African women and men
• people who inject drugs
• sex workers
• people who have recently migrated
• people who have condomless anal or vaginal sex with people at higher risk of HIV

If you are having unprotected sex and are concerned about it, you should speak about your health and lifestyle choices to find out if PrEP is right for you.

PrEP is almost 100% effective at preventing HIV, and the medications it contains are well-researched as they have been used in HIV care for many years.

Studies show that the PrEP once-daily regime reduces the risk of getting HIV from sex by around 99%. Further studies found that PrEP effectiveness sat at around 93% in people who took it regularly, however, this was reduced to 86% in people who had periods of stopping and starting PrEP.

"It is very important to take PrEP exactly as directed. Not doing so can increase your chances of getting HIV if you are exposed. For PrEP to be most effective, it can be taken daily. PrEP is also effective when taken “on demand”, providing you follow instructions. You should also continue to practice safe sex and use condoms to minimise your risk completely. It’s also vital to remember that even while using PrEP, you are also still vulnerable to other STIs." — Dr Clair Grainger, Medical Editor

PrEP is a prescription medication, so you'll need a prescription from a licensed healthcare professional before you can buy it. It’s important to only request PrEP online from trusted online services like ZAVA, which are monitored and regulated to ensure you receive safe and genuine prescriptions.

Getting PrEP online from ZAVA is quick and convenient, with no need for a face-to-face appointment. We can provide PrEP to both new and current users:

1.Complete a short online medical questionnaire

Share details about your health so our doctors can ensure PrEP is right for you.

2.Order and pay online

Sign in or create your ZAVA account, select PrEP, and securely make your payment.

3.Doctor review and approval

A UK-licensed doctor will check your health information and approve your request if PrEP is safe and appropriate for you.

4.Fast and discreet delivery

If approved, PrEP will be delivered discreetly to your home or a local post office for collection.

5.Ongoing care

Our doctors will be available to support you if you have any questions or concerns while taking PrEP. All you have to do is message them for free via your patient account.

When you request PrEP from us, our doctors will ask whether you’ve had:

• a negative HIV test result
• a normal kidney function test result
• a negative hepatitis B and C test result — you only need a negative hepatitis B result if you’ve not had a hepatitis B vaccination, and you only need a negative hepatitis C result if you are a man who has sex with other men or a trans woman, or have other risk factors for hepatitis C infection

You can still request PrEP if you haven’t taken one or more of these tests. However, you must take these tests before you begin taking PrEP. You can order any PrEP tests you need from us and complete these at home.

It’s also recommended that you do a full screen test for sexually transmitted infections (STIs).

How to get PrEP for free

You can get PrEP for free on the NHS if it’s suitable for you by going to a sexual health clinic, but you may still need to pay a prescription fee. At the clinic, you can explain that you need PrEP, and they will check to make sure it’s safe and suitable for you. Depending on your health and situation, your prescriber may want to conduct a few tests before starting PrEP.

You can find your nearest sexual health clinic using the NHS website.

Recent updates made to national PrEP guidelines mean that anybody eligible for PrEP (emtricitabine and tenofovir) can now start it with a double dose and become protected within 2 hours. This includes using PrEP on demand (around the time of having sex).

How you take PrEP will depend on whether you plan to take it daily or on demand. What works best for you will depend on your lifestyle and needs.

Daily

When you take PrEP daily, you:

• start by taking 2 tablets at least 2 hours before you have sex
• then take 1 tablet every day around the same time daily
• begin your daily dose ideally 24 hours after your initial double dose to stay protected from HIV

Daily PrEP is a great option if you do not like to plan sex or you do not want to worry about remembering to take PrEP when you do have sex, as it’s already part of your daily routine. Taking PrEP daily is also very effective in preventing HIV as it keeps you up to 99% protected from infection.

On-demand

On-demand means you only take PrEP when you need to, for example, if you have sex infrequently.

To do this, if you have anal sex or are the person giving frontal sex, you:

• take 2 tablets at least 2 hours before having sex
• then, take 1 tablet each day, for 2 days – start the daily tablet roughly 24 hours after the initial double dose
• keep taking 1 tablet every 24 hours until you’ve not had sex for at least 2 days (called 2:1:1 dosing)

2:1:1 dosing should not be used for people receiving frontal (vaginal) sex or in people who inject drugs, as it does not provide effective enough HIV prevention.

To do this, if you are a cis woman, trans, or non-binary person receiving frontal sex (and in people who inject drugs), you:

• take 2 tablets at least 2 hours before having sex
• take 1 tablet each day for 7 days following an initial double dose (called 2:7 dosing) – start the daily tablet roughly 24 hours after the initial double dose
• keep taking 1 tablet every 24 hours until you’ve not had sex for at least 7 days

If you do not have sex regularly or do not want to remember to take a tablet every day, on-demand PrEP is a great way of making sure you’re protected from HIV when you need to.

Taking PrEP on demand can be just as effective as taking it daily, as long as you remember to take it on time. Missing even 1 tablet can reduce the effectiveness of your treatment.

Tuesday, Thursday, Saturday, and Sunday dosing (TTSS)

If you have already been using a daily dose of PrEP for at least 7 days, you can choose to take your dose on Tuesdays, Thursdays, Saturdays, and Sundays (TTSS) if you prefer. This may be an option for you if event-based dosing is not right for you or if you get side effects when taking PrEP daily.

When should I start taking PrEP?

You should start PrEP with a double dose at least 2 hours before you want to have sex. Then continue taking 1 tablet daily.

You should start taking PrEP on demand at least 2 hours before having sex. Then, continue the treatment schedule to stay protected.

PrEP is meant to be taken as a preventative measure before you have sex. If you’ve had sex and think there’s a chance that you’ve been exposed to HIV, you’ll need a different treatment called post-exposure prophylaxis (PEP). You can get this from a sexual health clinic and it must be taken within 72 hours of exposure. If it’s a weekend or you cannot access a sexual health clinic for any reason, PEP is also available at A&E.

Do I need to be HIV negative before taking PrEP?

Yes, you must be HIV-negative before taking PrEP. PrEP is only a treatment that reduces the risk of getting HIV. It's not a treatment for HIV. Taking PrEP while you are HIV positive can cause drug resistance, which can actually make it more difficult to treat HIV.

If you’ve possibly been exposed to HIV and are out of the window for PEP (longer than 3 days since exposure) or have HIV symptoms, inform your doctor and take a HIV test. If you have no symptoms of HIV but you’ve had a potential exposure to HIV in the 6 weeks before starting PrEP, you should take another HIV test 6 weeks after starting PrEP and then at 3 months after starting PrEP. If you’re not sure, our doctors can help.

How long should I take PrEP for?

PrEP can be taken continuously for as long as you need to take it. If you wish to stop taking PrEP, you should take a tablet daily for 2 days after last having anal sex or sex where you insert your penis (such as frontal sex), or 7 days after last receiving frontal sex.

When used correctly, PrEP (emtricitabine and tenofovir) generally causes little or no side effects. However, any medication has the potential to cause side effects which can vary from person to person.

As with most medication, vomiting, breathing difficulties, swelling of the skin or a rash may occur if you have an allergy or intolerance to any of the components of the medication. If you develop any of these symptoms after taking PrEP, stop it immediately and seek medical attention urgently.

Most people who take PrEP will not experience side effects, but if they do, these usually resolve within a few weeks. Common side effects include:

• diarrhoea or vomiting
• heartburn or indigestion
• headaches
• dizziness
• tiredness or insomnia
• abnormal dreams
• rashes
• pain or feeling weak
• changes in your liver enzymes
• changes in the levels of your blood sugar and blood fats
• lowering of your white blood cells

Are there any long-term side effects?

PrEP can affect kidneys and bones over the long term in some people. You will need to have a kidney test before you start taking PrEP and during your treatment, and our doctors will also ask about your medical history.

In the PROUD study, participants reported few side effects, and almost everyone who stopped PrEP because of side effects were able to start PrEP again. No significant health effects have been seen in people who are HIV-negative and have taken PrEP for up to 5 years.

If you develop any of the above side effects or any other symptoms, please see your GP to investigate this. You should also speak with your GP or sexual health clinic if you have ever been told you have osteoporosis, osteopenia, or have risk factors for this, such as being post-menopausal or a smoker. They may recommend an alternative type of PrEP with less effect on bone mineral density.

Always make sure you read the patient information leaflet that comes with your medication before starting the medication.

PrEP is safe to take with most other medications. However, there are some exceptions and some medications where increased monitoring might be required, such as if you’re taking daily PrEP and daily antiviral medication like aciclovir. Always consult your doctor before taking new medications.

You should not take non-steroidal anti-inflammatory drugs (NSAIDs) routinely with PrEP, as your risk of kidney damage increases. These include:

• ibuprofen
• diclofenac
• naproxen

PrEP is safe for non-binary or transgender people who take hormones.

To take care of yourself while taking PrEP, it’s important to take any tests requested by a doctor, such as your 3-month continuation PrEP test. This test makes sure you can stay on PrEP and it checks your HIV status and kidney function. If your kidney function is normal and you are HIV-negative, you can continue taking PrEP for another 3 months. We provide this test kit so you can do it at home.

At least once a year you will also need to check your HIV status, kidney function, and Hepatitis B or C status (if this applies to you). We provide an annual continuation PrEP test kit that enables you to test for all of this at home too.

More frequent kidney tests are recommended if you are: at higher risk of kidney disease, such as if you are aged over 40, have diabetes, or high blood pressure.

We also recommend getting regular STI screenings while you’re on PrEP, which we can also provide. While PrEP helps protect you from HIV, you’re still vulnerable to other STIs, especially if you’re not using protection during sex. So a good way of taking care of yourself while on PrEP is to make sure you’re still practicing safe sex.

Getting more support

Depending on your circumstances, you may need a little more support while taking PrEP. These resources may be helpful if needed:

• Mermaids – a charity that supports trans, non-binary and gender-diverse children, young people and their families
• Gay Men Fighting AIDS (also known as GMFA) – a group that provides information on the history of HIV and its treatment to keep you informed and combat the stigma associated with it.

Does PrEP protect you from other STIs?

PrEP does not offer any protection from other STIs, it only protects you against HIV.

Is PrEP the same as PEP?

No, PrEP is designed to prevent HIV and is taken before a risk of exposure. PEP (post-exposure prophylaxis) is taken as an emergency after possible exposure to HIV.

Does PrEP cure HIV?

No, PrEP is not suitable for people who are HIV positive.

Is PrEP effective after exposure?

PrEP must be taken both before and after exposure at the intervals directed to be effective. Only taking PrEP after exposure is not effective. If you think you have been exposed to HIV, contact a doctor or sexual health clinic immediately.

Is PrEP safer than condoms?

PrEP only protects you against HIV, whereas condoms offer protection against both HIV and other STIs.

Does PrEP affect male fertility?

According to this study, taking PrEP does not affect the fertility of men who are HIV negative.

How many hours late can I take PrEP?

If you are taking daily doses, you should take your tablet at about the same time every day to maintain sufficient levels of the drug in your body to protect you from getting HIV. If you forget, take it as soon as you remember, and get in touch with your doctor or sexual health clinic if you have been taking less than 4 doses of PrEP a week (remember the TTSS schedule is 4 doses a week). Do not take more than 1 tablet at a time, unless it’s your starting double dose.

If you are dosing ‘on-demand’ or ‘event-based’ before and after sex, you must take PrEP at the correct intervals. If you do not, contact your doctor or sexual health clinic immediately.

How do you know if someone is on PrEP?

There is no way you can tell if someone else is taking PrEP. Only you can be sure if you are using PrEP to protect you from HIV.

Can you take PrEP with contraception?

Yes, PrEP can be used safely with all contraceptive methods.

Can I use PrEP while pregnant or breastfeeding?

Yes. PrEP is not known to affect your chances of pregnancy. It can be safely used by pregnant and/or breastfeeding people, but we recommend that you first contact your midwife, GP, or local sexual health clinic before doing so.

Can PrEP be used as PEP?

No, PrEP can not be used as PEP. While the same medication can be used for both treatments, they are taken in different ways and require different dosing and scheduling. PrEP is to be taken before you have sex and is known as pre-exposure treatment, while PEP is for post-exposure (after you have had sex). PEP is often a combination of 3 medications, while PrEP is usually 2.

Does PrEP interact with other drugs or alcohol?

PrEP does not interact with alcohol, so it’s usually safe to take while drinking. However, taking recreational drugs while on PrEP may change how they affect you, especially if you’re new to PrEP or have just started taking it. Recreational drugs can also increase your likelihood of experiencing side effects with PrEP, so it’s best to inform your doctor if you are taking recreational drugs when requesting PrEP.