Active Ingredient

Efavirenz

Efavirenz is an antiretroviral medication used to manage and treat HIV infection. It is often part of a combination therapy to help control the virus.

This medication helps in reducing the viral load in the body, thereby improving the immune system function.

Written By Douglas C. Goldberg, MD

Reviewed By Philip Schein, MD

Last Updated 28 Nov 2025

Available Efavirenz Brands

Sustiva

Strengths 200mg, 600mg

Efavirenz Uses

Efavirenz is primarily used in the treatment of HIV. It is usually combined with other antiretroviral agents.

Management of HIV infection
Part of combination therapy for HIV
Helps reduce the risk of HIV-related complications

How Efavirenz Works

Efavirenz works by inhibiting the activity of reverse transcriptase, an enzyme crucial for the replication of HIV. By blocking this enzyme, the medication prevents the virus from multiplying.

This action helps to reduce the amount of virus in the body, allowing the immune system to function more effectively.

Common side effects of Efavirenz

Not everyone experiences side effects with Efavirenz, and many are mild and temporary. However, some common side effects can occur.

Dizziness
Headache
Nausea
Rash
Insomnia
Fatigue
Stomach upset

If side effects are severe or persistent, contact your doctor.

Frequently Asked Questions

What is Efavirenz used for?

Efavirenz is used to help control and manage HIV infection as part of combination antiretroviral therapy.

How does Efavirenz work?

Efavirenz works by inhibiting the reverse transcriptase enzyme, which is necessary for HIV replication.

Can Efavirenz cause dizziness?

Yes, dizziness is a common side effect of Efavirenz. It is advisable to avoid driving if you experience this symptom.

Is it safe to drink alcohol while taking Efavirenz?

It is best to avoid alcohol while taking Efavirenz, as it can increase the risk of side effects.

What should I do if I miss a dose of Efavirenz?

If you miss a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed dose and continue your regular schedule.