Tenofovir: Uses, Dosage, Side Effects, and Practical Tips
Tenofovir is one of the core drugs used to treat HIV and chronic hepatitis B, and it’s also a key part of many PrEP regimens to prevent HIV. If you or someone you care for is prescribed tenofovir, this page explains what it does, the common forms you’ll see, and simple steps to use it safely.
How tenofovir works and the main uses
Tenofovir blocks the virus’s ability to copy its genetic material. You’ll find it in two main forms: tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF). Both stop viral replication, but they differ in dose and side-effect profile. TDF is widely used for HIV treatment and PrEP (usually combined with emtricitabine). TAF is a newer form used in some HIV treatments and is often chosen for people with kidney or bone concerns because it reaches higher levels inside cells at a lower dose.
Common uses: treating HIV as part of combination therapy, preventing HIV infection (PrEP), and managing chronic hepatitis B. If you have hepatitis B, stopping tenofovir suddenly can cause a serious flare — talk to your doctor before stopping.
Practical dosing, side effects, and monitoring
Typical dosing depends on the formulation and the combination pill. For example, the common TDF/FTC PrEP pill is taken once daily. TAF is used in some single-tablet regimens at a lower milligram dose. Always follow the exact prescription on your bottle.
Watch for these side effects: the most common are nausea, headache, and mild stomach upset. TDF can affect kidney function and reduce bone mineral density in some people. TAF tends to have smaller effects on kidneys and bones but can increase blood lipid levels. Serious problems are less common but need early detection.
Simple monitoring steps: get baseline kidney tests (creatinine/eGFR) and hepatitis B status before starting. For PrEP users, plan for HIV testing and STI screening every three months. Check kidney function periodically — your provider will tell you how often based on your health and other meds.
Quick safety tips: take the pill at the same time each day to build a habit. Tell your clinician about all medicines and supplements you use — some drugs can raise kidney risk or change tenofovir levels. Avoid abrupt stopping if you have hepatitis B. If you miss one dose, take it as soon as you remember that day; don’t double up the next day without medical advice.
If you’re considering tenofovir for treatment or prevention, ask your provider about the differences between TDF and TAF, routine lab checks, and how it fits with any other health issues you have. Your pharmacist can also help with timing, side effects, and storage. Practical steps and small checks make tenofovir safer and more effective for most people.