Efavir Tablets (Efavirenz)

Efavir is a prescription antiretroviral (HIV-fighting) medicine used as part of combination therapy for HIV-1. This page explains practical basics—what it does, how it’s commonly taken, and what safety checks matter. Ships from Canada to US, and access is often set up as cash-pay for people without insurance.

Information here is meant to support informed conversations and smoother refills, not to replace clinical guidance. For broader context, the HIV Condition Hub and the HIV Treatment Landscape 2024 overview can help with terminology and regimen changes over time.

What Efavir Is and How It Works

This treatment contains efavirenz, which belongs to the non-nucleoside reverse transcriptase inhibitor (NNRTI, a type of HIV medicine) class. NNRTIs work by blocking a key HIV enzyme so the virus cannot make copies of itself efficiently. It is not used alone; it is paired with other antiretrovirals so the regimen targets HIV at multiple steps and lowers the chance of drug resistance.

Medication is dispensed by licensed Canadian partner pharmacies. US shipping from Canada is arranged after prescription review and processing. When reading about how this therapy works, it may help to browse related options in the Antivirals Category, since HIV regimens are typically built from more than one antiviral class.

Who It’s For

This medicine is generally used for people being treated for HIV-1 as part of a complete, clinician-selected regimen. It may be chosen when it fits prior treatment history, resistance testing, and the person’s other medications. Efavir should be taken exactly as prescribed and combined with other HIV medicines, because partial regimens can allow the virus to adapt.

Some situations require extra caution or a different option. A prescriber may avoid or closely monitor therapy in people with certain mental health conditions, seizure history, or significant liver disease, because neuropsychiatric symptoms and liver inflammation can occur. Pregnancy and breastfeeding decisions are individualized; bring current guidance to appointments and document all medicines, supplements, and over-the-counter products. For related planning topics, see Biktarvy in Pregnancy and the general prevention context in HIV Testing Day Guide.

Dosage and Usage

For many adults, the labeled schedule for efavirenz in combination therapy has been once daily, often taken at bedtime. Clinicians may also recommend taking it on an empty stomach to reduce certain nervous-system effects. The specific combination regimen (which companion drugs are used) depends on prior therapy, viral load, resistance patterns, and other health factors.

Efavir 600 mg tablet dosing is commonly discussed in standard regimens, but the right schedule and companion medicines must come from the prescription label. Do not change timing, skip doses, or stop therapy without guidance, because missed doses can raise the risk of resistance and treatment failure. If a dose is missed, follow the written instructions from the dispensing pharmacy or prescriber rather than doubling up.

Quick tip: Keep a current medication list in your phone for every refill request.

Daily-life factors can also affect tolerability, including sleep routines and alcohol or recreational substances. A practical discussion of day-to-day habits while on HIV therapy is available in Lifestyle While Taking Biktarvy, which covers planning considerations that apply across many regimens.

Strengths and Forms

This product is supplied as an oral tablet. Strength availability can vary by market and dispensing partner, and prescriptions are written for a specific strength and quantity. Efavir 600 mg tablets are commonly used for once-daily dosing in adults, while Efavir 200 mg tablet presentations may be used when a prescriber has selected that strength as part of a plan.

Tablets are typically swallowed whole with water. Do not split, crush, or chew a tablet unless a pharmacist confirms it is appropriate for the exact product supplied, because altering the tablet can change how the dose is delivered. Quantities may be dispensed in standard monthly supplies (for example, a 30-tablet fill), but the final quantity depends on the prescription instructions and dispensing practices.

If you are comparing regimen structures, a plain-language walkthrough of combination HIV treatment is in Beginner’s Guide to Biktarvy, which can make class names and “backbone” terms easier to follow.

Storage and Travel Basics

Store tablets at room temperature and keep them protected from excess heat, moisture, and direct light. Keep the bottle tightly closed and in its original container when possible, because labeled packaging helps protect the medicine and preserves key information such as lot number and expiration date. Always keep medicines out of reach of children and pets.

For travel, pack enough doses for the entire trip plus a small buffer for delays, and keep tablets in carry-on luggage rather than checked bags when flying. It also helps to carry a copy of the prescription or the pharmacy label, especially when crossing borders or moving through airport security. If you use a pill organizer, refill it from the original bottle and keep the labeled container with you.

Why it matters: Consistent storage reduces avoidable changes in tablet quality.

Side Effects and Safety

Many people notice nervous-system effects early in therapy, such as dizziness, abnormal dreams, trouble sleeping, or feeling “foggy.” Headache, nausea, tiredness, and mild rash can also occur. These effects may lessen over time for some people, but they should be documented and discussed, especially if they interfere with daily function or adherence.

Prescriptions are confirmed with prescribers before dispensing. Seek urgent medical care for symptoms that could signal a serious reaction, including severe rash, blistering or peeling skin, facial swelling, trouble breathing, severe mood changes, suicidal thoughts, confusion, yellowing of the skin or eyes, dark urine, or significant right-upper-abdominal pain. Efavir can also affect mental health symptoms in susceptible individuals, so clinicians may monitor mood and sleep more closely after initiation or dose changes.

Some HIV regimens can rarely be associated with lactic acidosis (a buildup of lactic acid), particularly in specific drug combinations or risk settings. Learn what warning signs can look like in Lactic Acidosis Symptoms, and bring any concerning symptoms to clinical attention promptly.

Drug Interactions and Cautions

Efavirenz is processed through liver enzymes and can speed up or slow down the breakdown of other drugs. This means interactions are a central safety issue, not a side note. A complete medication review should include prescription drugs, over-the-counter products, vitamins, and herbal supplements. St. John’s wort, for example, is a common supplement that can interfere with some HIV therapies.

Interaction checks to prioritize

Ask the dispensing pharmacist or prescriber to specifically review: (1) other antivirals and any regimen switches; (2) anticonvulsants and sedatives; (3) antifungals and antibiotics that affect liver enzymes; (4) hormonal contraception, because effectiveness can change with enzyme induction; and (5) methadone or other therapies where blood levels matter. If a clinic is considering PEP or other short-term prevention strategies, the interaction landscape can differ, and the overview in Biktarvy and PEP Use helps frame why regimen choice is situation-dependent.

Do not start or stop medicines that have known major interactions without professional guidance. When interacting drugs are unavoidable, clinicians may choose alternative agents, adjust companion therapy, or increase monitoring. For another example of how different HIV drug classes behave, see Aptivus Overview.

Compare With Alternatives

NNRTI-based options are only one part of modern HIV care, and many people use regimens anchored by integrase inhibitors or other classes. Within the NNRTI class, doravirine-based therapy is one alternative some clinicians consider, depending on resistance patterns and interaction concerns. Other NNRTIs, such as rilpivirine, may be used in specific circumstances, often with food requirements and interaction considerations of their own.

For reference, product pages for related NNRTI options include Pifeltro Product Page and Delstrigo Product Page. These are not “better or worse” choices in general; they are different tools. Clinicians typically choose among options based on resistance testing, kidney and liver status, pregnancy considerations, mental health history, and the person’s full medication list.

Pricing and Access

Out-of-pocket costs for antiretrovirals can vary based on strength, quantity, manufacturer (brand versus generic), and the dispensing partner’s sourcing. If you see references such as Efavir 600 mg 30 tablets, those describe a common monthly quantity rather than a guarantee of packaging. Efavir is a prescription-only medicine, and a valid prescription is required before it can be dispensed.

Cash-pay access can help people without insurance. The platform coordinates prescription referral with Canadian partner pharmacies and verifies the prescription with the prescriber as part of the dispensing process. For general billing and assistance information, visit Payment and Savings Options. If a refill is urgent, submit requests early so any needed clarifications can be handled before processing.

Authoritative Sources

The most reliable details on dosing, contraindications, and interaction lists come from official labeling and clinical guidance. If anything in routine use differs from what is written on a label, clinicians usually have a documented reason, such as resistance results, comorbid conditions, or a switch strategy. When reviewing sources, focus on the efavirenz active ingredient and the specific product formulation being used.

These links provide neutral, label-based and guideline-based references for efavirenz safety and use in HIV care. They are helpful for cross-checking side effects, interaction warnings, and monitoring topics to discuss at appointments.

• FDA Drugs@FDA listing for efavirenz products
• MedlinePlus patient drug information for efavirenz
• NIH Clinicalinfo efavirenz patient information

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This content is for informational purposes only and is not a substitute for professional medical advice.