What the label lists and what reports show
Efavirenz side effects
Efavirenz's FDA label: “Most common adverse reactions (>5%, moderate-severe) are impaired concentration, abnormal dreams, rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting.” FAERS holds 11,083 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is virologic failure (958 reports).
- Generic listed
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of efavirenz tablets?Efavirenz tablets may cause serious side effects, including: Serious mental health problems can happen in people who take efavirenz tablets. Tell your doctor right away if you have any of the following symptoms: feel sad or hopeless feel anxious or restless have thoughts of hurting yourself (suicide) or have tried to hurt yourself or others are not able to tell the difference between what is true or real and what is false or unreal do not trust other people hear or see things that are not real are not able to move or speak normally Nervous system symptoms are common in people who take efavirenz tablets and can be severe. These symptoms usually begin during the first or second day of treatment with efavirenz tablets and usually go away after 2 to 4 weeks of treatment. Some symptoms may occur months to years after beginning efavirenz tablets therapy. […]
Source: FDA drug label (Efavirenz), Aurobindo Pharma Limited, effective December 29, 2023 (SPL set c5eedb5d-4cab-4056-a14a-ffdf67701355), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (>5%, moderate-severe) are impaired concentration, abnormal dreams, rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting.
Table2:Selected Treatment-Emergent a Adverse Reactions of Moderate or Severe Intensity Reported in ≥2% of Efavirenz-Treated Patients in Studies 006 and ACTG364
| Adverse Reactions | Study 006 Efavirenz b +ZDV/LAM (n=412) 180 weeks c | LAM-, NNRTI-, and Efavirenz b +Indinavir (n=415) 102 weeks c | Protease Inhibitor- Naive Patients Indinavir +ZDV/LAM (n=401) 76 weeks c | Study ACTG 364 NNRTI- ,and Protease Efavirenz b +Nelfinavir + NRTIs (n=64) 71.1 weeks c | NRTI-experienced, Inhibitor-Naive Efavirenz b +NRTIs (n=65) 70.9 weeks c | Patients Nelfinavir +NRTIs (n=66) 62.7 weeks c |
|---|---|---|---|---|---|---|
| Fatigue | 8% | 5% | 9% | 0 | 2% | 3% |
| Pain | 1% | 2% | 8% | 13% | 6% | 17% |
| Dizziness | 9% | 9% | 2% | 2% | 6% | 6% |
| Headache | 8% | 5% | 3% | 5% | 2% | 3% |
| Insomnia | 7% | 7% | 2% | 0 | 0 | 2% |
| Concentration impaired | 5% | 3% | <1% | 0 | 0 | 0 |
| Abnormal dreams | 3% | 1% | 0 | – | – | – |
| Somnolence | 2% | 2% | <1% | 0 | 0 | 0 |
| Anorexia | 1% | <1% | <1% | 0 | 2% | 2% |
| Nausea | 10% | 6% | 24% | 3% | 2% | 2% |
| Vomiting | 6% | 3% | 14% | – | – | – |
| Diarrhea | 3% | 5% | 6% | 14% | 3% | 9% |
| Dyspepsia | 4% | 4% | 6% | 0 | 0 | 2% |
| Abdominal pain | 2% | 2% | 5% | 3% | 3% | 3% |
| Anxiety | 2% | 4% | <1% | – | – | – |
| Depression | 5% | 4% | <1% | 3% | 0 | 5% |
| Nervousness | 2% | 2% | 0 | 2% | 0 | 2% |
| Rash d | 11% | 16% | 5% | 9% | 5% | 9% |
| Pruritus | <1% | 1% | 1% | 9% | 5% | 9% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe most significant adverse reactions observed in patients treated with efavirenz are: psychiatric symptoms [see Warnings and Precautions ( 5.5 )] nervous system symptoms [see Warnings and Precautions ( 5.6 )] rash [see Warnings and Precautions ( 5.8 )] hepatotoxicity [see Warnings and Precautions ( 5.9 )] Most common adverse reactions (>5%, moderate-severe) are impaired concentration, abnormal dreams, rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Cipla Ltd. at 1-866-604-3268 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, the adverse reaction rates reported cannot be directly compared to rates in other clinical studies and may not reflect the rates observed in clinical practice. Adverse Reactions in Adults The most common (>5% in either efavirenz treatment group) adverse reactions of at least moderate severity among patients in Study 006 treated with efavirenz in combination with zidovudine/lamivudine or indinavir were rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting. Selected clinical adverse reactions of moderate or severe intensity observed in ≥2% of efavirenz-treated patients in two controlled clinical trials are presented in Table 2 .
Source: FDA drug label, Cipla USA Inc., effective March 31, 2024 (SPL set 92603fa5-7a2c-4bfb-9a70-aadb4fba952c), via openFDA; the full label on DailyMed
What do FAERS reports show?
11,083 reports list efavirenz among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,540 are coded as a death and 2,892 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 18 reactions below, 5 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Efavirenz: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions