How Does Tenofovir Work: Main Thing About Mechanism of Action

HIV affects millions of people worldwide. According to the WHO, this infection is a global epidemic challenge that has claimed the lives of many people. Tenofovir is a highly effective drug used as a combination with another medicine to prevent HIV acquisition or treat the virus.

Here is the full info about tenofovir medication, how it works, as well as for what period of time the medicine is effective. Let’s get started.

What Is Tenofovir Medication?

Tenofovir disoproxil fumarate (TDF) is an active substance used in various antiretroviral medicines in a combination to manage an HIV infection or as PrEP. TDF is also used to treat chronic (long term) HBV [1].

Tenofovir belongs to a drug class of nucleoside reverse transcriptase inhibitors (or NRTIs). It is also a hepatitis B reverse transcriptase inhibitor (RTI).

The patient’s health is paramount, and it’s necessary for a doctor to assess it for the possibilities of liver, bone, and kidney problems, among other conditions, which might be worsened by TDF usage [2].

How Does TDF (Tenofovir) Work?

Both NRTI and RTI groups of meds work in a similar way and are used to treat similar health conditions. This drug functions as a remedy for HIV and chronic hepatitis B.

Tenofovir mechanism of action consists of blocking the effectiveness of a protein, called reverse transcriptase (RT), which is an enzyme essential for each virus to multiply (or increase in number). If the action of RT is blocked, the amount of virus in the body is reduced [3].

The more tenofovir (in combination with other meds) blocks the reverse transcriptase, the higher the amount of virus (viral load) that is decreased in the body. Consequently, the CD4+ cell count is increased and the immune system can function as normal. Strengthening immunity helps infected individuals lower the chance of getting HIV-related complications (such as opportunistic infections and cancer) and also improves the quality and longevity of life.

In patients with HBV infection, proper and timely treatment with tenofovir lowers the risk of liver complications, including liver damage.

Various strengths are available for this drug in the oral form. They include: 150 mg, 200 mg, 250 mg, and 300 mg.

For HIV and chronic hep B infection, patients aged more than 18 years (and also children aged 12–17 years who weigh at least 35 kg) should take 300 mg tab every day [4]. It is not advised to take this medication based on general recommendations. Always seek the advice of a certified medical professional, who can assess your health and determine the correct dosage.

How Long Is Tenofovir Effective?

Tenofovir DF is metabolized to tenofovir diphosphate. This active substance is a competitive inhibitor of reverse transcriptase that effectively puts an end to the growing viral DNA chain.

Tenofovir DF manifests longer serum and intracellular half-lives compared to those of other nucleoside analogs. It means that it can sustain high levels in the patient’s blood, thus influencing the whole system.

For example:

  • serum half-life is 17 hours;
  • intracellular half-life is > or =60 hours.

By exhibiting these effects, it sustains a flexible once-a-day tenofovir administration schedule [5].


  1. Revised: February 15, 2019.
  2. Tenofovir Disoproxil Fumarate. Reviewed: April 11, 2019.
  3. Tenofovir disoproxil. Mechanism of action. Updated: December 23, 2019.
  4. Tenofovir, Oral Tablet. How to take tenofovir. Retrieved: December 20, 2019.
  5. Tenofovir disoproxil fumarate: clinical pharmacology and pharmacokinetics. Kearney BP, Flaherty JF, Shah J. Published: 2004.