Efavirenz: What It Is, How It Works, and What You Need to Know

When you're managing HIV, Efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI) used to block HIV replication. Also known as Sustiva, it's one of the most common drugs in first-line HIV treatment regimens worldwide. Unlike some newer medications, Efavirenz has been around for decades, but it still plays a major role — especially in low-cost treatment programs. It doesn’t cure HIV, but when taken daily with other antiretrovirals, it keeps the virus from multiplying, helping your immune system stay strong.

What makes Efavirenz different isn’t just how it works — it’s how your body reacts to it. Many people report vivid dreams or trouble sleeping, especially in the first few weeks. Some feel dizzy, nauseous, or even experience mood changes. These side effects aren’t rare — they’re common enough that doctors often advise taking it at bedtime on an empty stomach. But here’s the thing: if you stop taking it because of side effects, you risk the virus becoming resistant. That’s why sticking with it, even when it’s uncomfortable, matters. Efavirenz also has serious drug interactions, especially with medications that affect liver enzymes like CYP3A4 and CYP2B6. Things like certain antibiotics, antifungals, or even St. John’s Wort can make Efavirenz less effective or more toxic. If you’re on other meds — even over-the-counter ones — talk to your provider before starting or stopping anything.

It’s not just about the pill itself. Efavirenz is part of a bigger system: antiretroviral therapy, a combination of drugs that attack HIV at different stages to prevent resistance. Most people take it with two nucleoside reverse transcriptase inhibitors (NRTIs) like tenofovir and emtricitabine. This combo is often called Atripla when packaged together. The goal isn’t just to lower your viral load — it’s to get it to undetectable levels, which means you can’t pass HIV to others. That’s a game-changer.

People on Efavirenz need regular blood tests to check liver function and viral load. If you’re pregnant or planning to be, your doctor will monitor you closely — Efavirenz isn’t usually recommended in early pregnancy due to potential risks to the baby. But for many, especially in resource-limited settings, it’s the most affordable and effective option available. It’s not perfect, but it’s proven. Thousands of people live healthy, long lives because of it.

Below, you’ll find real-world guides on how Efavirenz fits into daily life — from managing side effects to avoiding dangerous mix-ups with other meds. Whether you’re just starting treatment or have been on it for years, these posts give you practical, no-fluff advice you can use right away.