References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Tenofovir alafenamide (TAF) is a newer version of tenofovir used in HIV treatment. It’s a prodrug that delivers active tenofovir more efficiently to HIV-infected cells while significantly reducing exposure to bones and kidneys. TAF has become the preferred form of tenofovir in most modern HIV single-tablet regimens.
TAF vs TDF: What’s the Difference?
Tenofovir comes in two prodrug forms:
- Tenofovir disoproxil fumarate (TDF): The original form, used since 2001. Releases tenofovir throughout the body, causing some impact on bones and kidneys over time.
- Tenofovir alafenamide (TAF): The newer form, approved in 2015. Delivers tenofovir directly into CD4 cells (where HIV lives), reducing blood levels by 90% compared to TDF. This dramatically reduces bone and kidney side effects.
| Feature | TDF | TAF |
|---|---|---|
| Bone density impact | Moderate reduction | Minimal |
| Kidney function impact | Small but measurable | Minimal |
| Weight gain | Less | More |
| Lipid profile | Slightly improves | May worsen |
| Cost | Available as cheap generics | Branded (newer) |
Which HIV Medications Contain TAF?
- Descovy (TAF + emtricitabine)
- Genvoya (TAF + emtricitabine + elvitegravir + cobicistat)
- Odefsey (TAF + emtricitabine + rilpivirine)
- Biktarvy (TAF + emtricitabine + bictegravir)
- Symtuza (TAF + emtricitabine + darunavir + cobicistat)
Who Should Use TAF?
TAF is particularly beneficial for patients with:
- Reduced bone density or osteoporosis risk
- Existing kidney dysfunction
- Risk factors for long-term kidney or bone issues
TDF may still be preferred for patients with cardiovascular risk factors (due to TAF’s less favourable lipid profile) or cost considerations (TDF is available as cheaper generics).
Read more: What is HIV? | Bone health and HIV | TDF-based treatment
Frequently Asked Questions
Should I switch from TDF to TAF?
If you’re on TDF and have bone or kidney concerns, switching to TAF can help. However, if you’re stable and tolerating TDF well, the benefits of switching may be modest. Discuss with your HIV specialist.
Does TAF cause weight gain?
Yes, TAF is associated with more weight gain than TDF, particularly when combined with integrase inhibitors. For patients already struggling with weight, this is a consideration when choosing between TAF and TDF.
Related reading
- Efavirenz for HIV: An Older NNRTI Still in Use
- Eviplera: How This Anti-HIV Drug Works
- Dolutegravir: A Complete Guide to This HIV Medication
- Understanding Efavirenz in HIV Treatment
- Injectable HIV Treatment: Everything You Need to Know
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
