Truvada: what it treats, how to take it, side effects
Last updated September 3, 2026.
Truvada combines two antivirals - emtricitabine and tenofovir DF - that slow the spread of HIV in the body. Two jobs: treating HIV as part of combination therapy, and preventing it - PrEP - paired with safer-sex practices. It does not cure HIV.
What does it treat?
HIV treatment, with other antiretrovirals - and HIV prevention as PrEP, where it reduces the risk of infection alongside condoms and safer-sex practices. It does not prevent other sexually transmitted infections.
How do you take it?
One tablet once a day, same time daily, with or without food - exactly as directed. For PrEP, the daily habit is the protection: missed days are lost protection. The monitoring is part of the medicine: an HIV test before starting and at least every 3 months during PrEP, plus lab checks of kidney function and other markers. Report promptly any fever, tiredness, joint or muscle pain, rash, night sweats, vomiting, diarrhea, headache, sore throat, or swollen neck or groin while on PrEP - those can be early-infection signs. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: depression, anxiety, trouble sleeping, unusual dreams, pain, burning, or tingling in hands or feet, heartburn, and weight loss.
- Serious - call your doctor immediately or get emergency care: allergic swelling of face, throat, tongue, lips, eyes, or lower legs with hoarseness or trouble swallowing or breathing; the kidney-bone set - decreased or frequent urination, muscle pain, bone pain, unusual thirst; the liver set - nausea, vomiting, upper-right stomach pain, loss of appetite, flu-like symptoms, unusual bleeding or bruising, dark urine, light-colored stools, yellowing skin or eyes; and the lactic-acidosis set - feeling cold especially in arms or legs, fast or irregular heartbeat, dizziness, lightheadedness, stomach pain with nausea and vomiting.
Who should not take it?
The hepatitis B rule: it is not an HBV treatment - get tested before starting, because stopping the drug with HBV on board can flare the liver suddenly, and stopping is followed by months of monitoring. Flag kidney disease, bone problems including osteoporosis or fractures, liver disease, and lingering infections. PrEP is only for people confirmed HIV-negative - the testing cadence is non-negotiable.
When is it an emergency?
Throat swelling, trouble breathing, or severe dizziness with a racing heartbeat is a 911 call. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
What is the difference between Truvada for treatment and for PrEP?
Same tablets, different mission: for HIV treatment it is one part of a combination regimen holding the virus down; for PrEP it is the whole plan - taken by someone HIV-negative to stay that way, alongside condoms and safer-sex practices. The distinction drives everything else: PrEP starts with a confirmed negative test and retests at least every 3 months, because taking it with an undetected infection breeds resistance.
Why the HIV test every 3 months on PrEP?
Truvada does not always prevent HIV - and an infection that starts on PrEP can breed drug-resistant virus, narrowing future treatment options. The 3-month testing cadence catches any infection early. Same logic for the symptom watch: fever, tiredness, joint or muscle pain, rash, night sweats, vomiting, diarrhea, headache, sore throat, or swollen neck or groin after a possible exposure - report it promptly, do not wait for the next scheduled test.
What is the hepatitis B warning?
Truvada's ingredients also suppress hepatitis B - without treating it properly. If HBV is on board and the drug stops, the liver can flare suddenly, sometimes severely. That is why the HBV test comes before starting, and why stopping - for any reason - is followed by months of liver monitoring. Never start or stop this medication without the prescriber in the loop.
Why did my doctor order kidney and bone tests?
Tenofovir DF can stress the kidneys and thin bone over time - the serious list includes decreased or frequent urination, muscle or bone pain, and unusual thirst. The baseline and periodic labs catch drift early, when the fix is easy. If kidneys or bones are already a concern, the sister drug Descovy - with tenofovir AF - is often the gentler option; that choice belongs to your prescriber.
Does PrEP protect against other infections?
No - HIV only. Gonorrhea, syphilis, chlamydia, and the rest need their own prevention: condoms, testing, and vaccination where it exists. The PrEP visits typically bundle STI screening into the same 3-month cadence - one appointment, the full picture.
What happens if I miss a dose of Truvada?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. For PrEP, protection lives in consistency: occasional single misses matter less than a pattern - if days keep slipping, the anchor needs fixing (same time, paired with a meal or routine), and that is worth telling your prescriber honestly.