Emtricitabine/Tenofovir Disoproxil tablets are used to reduce the chance of getting HIV (human immunodeficiency virus) for those with a higher risk of exposure. This treatment is known as PrEP (pre-exposure prophylaxis).
The medication shares its name with its active ingredients, emtricitabine and tenofovir disoproxil. It is the most common form of PrEP in the UK.
The usual dose is 1 tablet every day.
30 tablets - £78.00
60 tablets - £150.00
90 tablets - £215.00
About emtricitabine/tenofovir disoproxil
What is emtricitabine/tenofovir disoproxil?
Emtricitabine/tenofovir disoproxil is a PrEP medication prescribed to those with a higher risk of getting HIV. It can reduce their chances of infection through unprotected sex by 99% when taken daily.
You may be more at risk of getting HIV if:
- you have sex with someone who has HIV and has not received treatment, or their viral load is detectable
- you share needles to inject drugs
- you are a sex worker
- you get STIs (sexually transmitted infections) regularly
If you have sex with someone without a condom, and you are not sure about their HIV status, you might be more at risk if you are:
- a man and you have sex with other men
- a transgender person and you have sex with men
- a woman and you have sex with bisexual people
- having sex with someone from a country with a high rate of HIV
Emtricitabine/tenofovir disoproxil is the most commonly used PrEP treatment in the UK. It is an unbranded medication. You may come across the same treatment under the branded name, Truvada.
The medication is named after its 2 active ingredients, emtricitabine and tenofovir disoproxil.
Emtricitabine/tenofovir disoproxil can also be used with other medications to treat HIV. Asda Online Doctor does not prescribe medication for HIV treatment if you are HIV positive already. We explain why, below.
How does emtricitabine/tenofovir disoproxil work?
The active ingredients in emtricitabine/tenofovir disoproxil (emtricitabine and tenofovir disoproxil) are antiretroviral medicines. They can stop viruses from multiplying and spreading in the body.
Before starting PrEP
Yes, you will need to have some tests before taking this PrEP medication. These should be done no more than 4 weeks before you start and include:
- an HIV test*, as the antiretroviral drugs in PrEP are used to treat HIV too and you can build a resistance to these if you’re already HIV positive
- kidney function tests as PrEP can affect your kidneys)
Also, you may need:
- a hepatitis B test if you have not been vaccinated or don’t know your status for this
- a hepatitis C test if you are a man who sex with other men
PrEP can affect your condition and any future treatment you receive if you have hepatitis B or C.
*If you've had unprotected sex before starting PrEP, you need to wait at least 4 weeks after this before taking an HIV test, to make sure this is negative. Some tests give accurate results after different times, so check with a doctor if you are not sure.
It is recommended that you regularly test for other sexually transmitted infections such as chlamydia, gonorrhoea and syphilis, too.
While taking PrEP
Once you begin taking your PrEP medication, you should take:
- an HIV test every 3 months
- an HIV test and a kidney function test** once a year, plus a hepatitis B and C test if these apply to you (see above)
** If you have a high risk of kidney disease, you should take a kidney function test every 6 months.
Get tested through Asda Online Doctor
We offer 2 home PrEP test kits which cover these tests. Choose from our:
- advanced profile kit which checks your HIV status, kidney function and hepatitis status
- basic profile kit which checks your HIV status and kidney function only.
We also offer a standalone kidney function test, if this is the only thing you need to check. For example, you’ve done a HIV test separately and you don’t need to check your hepatitis status.
Order your PrEP test kit through us and get free home delivery. When your test kit arrives, collect your sample and send this away to our laboratory for analysis. Your results will be sent to your Asda Online Doctor account with advice on what to do next. You can take these PrEP tests through another provider or your GP, if you wish.
You can order emtricitabine/tenofovir disoproxil from us before you have completed these tests. However, for your safety, you must complete these tests and have your results before you start taking emtricitabine/tenofovir disoproxil. We will remind you about this when you complete your medication order.
Emtricitabine/tenofovir disoproxil should be taken once every day, with food if possible. It’s best to take this at the same time each day ('daily dosing') though there are other ways to take PrEP (for example, 'on demand dosing'). You can find out more about these through your local sexual health clinic or GP.
If you vomit less than an hour after taking a tablet, you should take another tablet. If you vomit more than an hour after taking a tablet, you do not need to take another. If you take more emtricitabine/tenofovir disoproxil than you should, speak to a doctor straight away. You can call 111, or go to your nearest sexual health clinic (or A&E if it's outside of clinic hours).
It is very important that you do not miss a dose of emtricitabine/tenofovir disoproxil. If you miss a dose, you are at a higher risk of getting HIV.
If you do miss a dose and it has been:
- less than 12 hours after you would normally take it, take that dose as soon as you can, then continue as normal
- over 12 hours since you would normally take it, miss that dose and wait to take your next dose at the usual time.
If you miss a dose, practicing safe sex methods, like wearing a condom, can help reduce your chance of getting HIV.
Once you start emtricitabine/tenofovir disoproxil, it can take 7 days to start working and for you to be protected. You should use other protection in the meantime, like condoms. If you want to stop using PrEP, speak to your doctor first so they can advise how to do this safely.
Emtricitabine/tenofovir disoproxil is not suitable if you take some medications. You should speak to your doctor before using this treatment if you take:
- medication for viral, bacterial, or fungal infections, such as ganciclovir, vancomycin, and aminoglycosides
- interleukin-2 (cancer treatment)
- non-steroidal anti-inflammatory drugs, used to relieve muscle or bone pains
- medication to treat hepatitis C, such as ledipasvir/sofosbuvir
You must not take emtricitabine/tenofovir disoproxil if you take any other medicines containing the same active ingredients, or other antiviral medications containing alafenamide, adefovir dipivoxil, tenofovir, or lamivudine.
Emtricitabine/tenofovir disoproxil can have some serious side effects, including:
- excess lactic acid in the blood, which may cause stomach pain, drowsiness, or rapid breathing
- autoimmune disorders, which can cause muscle weakness, hyperactivity, or palpitations
If you notice any of these symptoms, go to A&E or call 999 straight away.
Common side effects of emtricitabine/tenofovir disoproxil include:
- feeling weak
- nausea or vomiting (feeling or being sick)
- trouble sleeping
- stomach pain
- allergic reactions, such as swelling or wheezing
- a reduction in white blood cells
Uncommon side effects include:
- swelling in the lips, tongue, throat, or face
- muscle pain or weakness
- inflammation of the pancreas, which can cause pain in the stomach
- a reduction in red blood cells (anaemia)
- changes to your urine
Rare side effects include:
- fatty liver
- inflammation of the liver, which may cause pain in the stomach, itching, and yellow skin
- bone pain or increased fractures
- kidney problems
Since emtricitabine/tenofovir disoproxil can cause dizziness, do not drive or use heavy machinery if you feel dizzy. If you notice any serious side effects, or your side effects do not go away after a few days, speak to your doctor. For further information on side effects, see the patient information leaflet.
Emtricitabine/tenofovir disoproxil can affect your kidneys. If you have severe kidney disease or are currently on dialysis, this treatment is not recommended.
If you are pregnant or breastfeeding, speak to your doctor before using emtricitabine/tenofovir disoproxil. If you have an intolerance to sugars, speak to your doctor as emtricitabine/tenofovir disoproxil contains lactose.
Dr Kathryn Basford
Dr Kathryn Basford is a qualified GP who works as a GP in London, as well as with ZAVA. She graduated from the University of Manchester and completed her GP training through Whipps Cross Hospital in London.Meet our doctors
Article created: 28 Sep 2021
Last reviewed: 29 Jun 2022
Emtricitabine/Tenofovir disoproxil Mylan 200 mg/245 mg film coated tablets (2021) EMC (accessed 16 September 2021)
HIV and AIDS (2021) NHS (accessed 16 September 2021)
Pre-Exposure Prophylaxis (2021) HIV.gov (accessed 16 September 2021)
PrEP (pre-exposure prophylaxis) (2021) CDC (accessed 16 September 2021)
Single Dose Truvada in HIV-negative Men and Women (2012) ClinicalTrials.gov (accessed 16 September 2021)