Emtricitabine/Tenofovir Disoproxil
Sold as Truvada
Truvada is used two ways: as part of a combination regimen to treat HIV, and on its own as daily PrEP (pre-exposure prophylaxis) to prevent HIV infection in people who are HIV-negative. A generic version is FDA-approved and often dramatically cheaper than brand Truvada.
Boxed warning
Boxed warning (class effect): lactic acidosis and severe hepatomegaly with steatosis have been reported with nucleoside analogs. Severe acute exacerbation of hepatitis B has occurred after stopping this product in patients coinfected with HIV and HBV — hepatitis B status must be checked before stopping.
What it treats
1) HIV treatment: used in combination with other antiretrovirals for HIV-1 infection. 2) PrEP: taken daily by HIV-negative adults and adolescents (≥35 kg) to reduce the risk of sexually acquired HIV. Truvada is one of two FDA-approved daily oral PrEP options (the other is Descovy, which is not approved for receptive vaginal-sex PrEP). Truvada is generally the preferred PrEP option during pregnancy per CDC guidance, since more safety data exist for it in pregnancy than for Descovy.
Typical dosing
One tablet (200 mg emtricitabine/300 mg tenofovir disoproxil fumarate) by mouth once daily, with or without food, for both the treatment and PrEP indications. For PrEP, an HIV test is required before starting and periodically (at least every 3 months) while continuing.
Monitoring
Kidney function (creatinine/eGFR) before starting and every 6–12 months — tenofovir disoproxil fumarate (TDF) has a higher renal and bone-density impact than the newer tenofovir alafenamide (TAF, used in Descovy/Biktarvy). Bone density monitoring may be considered with long-term use or risk factors. HIV testing before starting PrEP and at least every 3 months while on it. Hepatitis B screening before starting.
Side effects
Common: nausea, diarrhea, headache. Serious (rare): kidney problems (Fanconi syndrome), decreased bone mineral density, lactic acidosis/severe liver problems (class effect), hepatitis B flare if stopped in a coinfected patient.
Interactions to know
Avoid combining with other tenofovir-containing products. Certain nephrotoxic drugs can compound kidney risk. Antacids/supplements with calcium, iron, magnesium, or aluminum can reduce absorption if taken at the same time.
Cost assistance programs
Gilead Advancing Access offers copay assistance for eligible commercially insured patients (often $0 copay) and support for the uninsured — enroll at https://www.gileadadvancingaccess.com/. For PrEP specifically, the HHS-funded Ready, Set, PrEP program provides PrEP medications at no cost to eligible people without prescription drug coverage — see https://readysetprep.hiv.gov/. A generic version of Truvada is also available and often the lowest-cost path for either indication — compare live prices above.
Pregnancy & breastfeeding
CDC guidance identifies Truvada as the preferred PrEP option during pregnancy and while breastfeeding, given the larger body of safety data compared to Descovy. For HIV treatment, tenofovir disoproxil-containing regimens are well-studied and commonly used in pregnancy under HIV specialist care.
Additional notes
Resistance considerations: for PrEP, Truvada only works to prevent infection if taken consistently — missed doses reduce protection, and starting PrEP while already HIV-positive (undiagnosed) risks drug resistance, which is why HIV testing before and during PrEP is required, not optional. For treatment, Truvada is always used in combination with other antiretrovirals, never alone. Generic emtricitabine/tenofovir disoproxil is FDA-approved and typically far cheaper than brand Truvada — ask your pharmacist about the generic for either indication.
Clinical content reviewed by the BetterBuyRx clinical team, on 2026-07-07.
Educational only. Not medical advice. Always confirm with your prescriber or pharmacist.