Umifenovir
Pronunciation: yoo-mih-FEN-oh-veer.
- Generic name
- umifenovir
- Brand names
- Arbidol
- Drug class
- Antiviral agent (viral membrane-fusion inhibitor with reported interferon-inducing/immunomodulatory activity)
- Form
- Capsule, tablet, dispersible tablet, granules for oral suspension, or oral suspension powder, depending on country and manufacturer
- Route
- Oral
- Legal status
- Not approved by the US FDA, European Medicines Agency, or UK MHRA. Registered as a pharmaceutical product in Russia and China. This dossier could not independently confirm whether it is classified prescription-only or over-the-counter in either country against a primary regulator source, so no supply badge is shown.
Availability and supply rules vary by country
Trade names by country: China
Australia: · Full directory
What umifenovir is and how it works
Umifenovir is a synthetic antiviral medicine, marketed under the brand name Arbidol, that is registered in Russia and China for the treatment and prevention of influenza A and B and other acute respiratory viral infections (ARVIs). It does not have a US FDA prescribing label, a DailyMed entry, a MedlinePlus monograph, or a UK electronic Medicines Compendium (EMC) product listing, and it is not authorised in the United States, United Kingdom, European Union, Australia, Canada, or most other countries. (1) (2) (8) (9) (6)
Umifenovir's evidence base is smaller and more contested than many internationally approved antivirals. Placebo-controlled randomized trials conducted in Russia and China support a modest reduction in influenza/acute respiratory infection symptom duration when treatment is started within about 36 hours of symptom onset. During the COVID-19 pandemic umifenovir was widely used off-label in China, but an independent systematic review of 16 studies found no significant benefit over non-antiviral treatment on virus-clearance or clinical outcomes and a higher rate of adverse events, and a 2025 randomized controlled trial concluded that routine use of umifenovir for COVID-19 'is currently not justified.' Independent commentators, including Russia's own Academy of Medical Sciences in 2007, have publicly questioned whether umifenovir's benefits are adequately proven. Because of these evidence limitations, this page describes a country-specific, evidence-limited medicine rather than a globally endorsed antiviral, and several sections below are deliberately left incomplete where authoritative evidence could not be found.
Mechanism of action: how umifenovir works
Umifenovir is proposed to act as a viral membrane-fusion inhibitor, interacting with viral hemagglutinin and blocking fusion of the viral lipid envelope with the host-cell membrane; it has also been described as having interferon-inducing and immunomodulatory properties (including effects on T-cell proliferation and macrophage function) in Russian pharmacological reference material. Reported elimination half-life is approximately 17-21 hours, with roughly 40% excreted unchanged via bile according to a Russian drug-reference source. This dossier did not independently verify these pharmacokinetic figures against a primary regulator source. (1) (3) (4)
What umifenovir is used for
Treatment of influenza A and B and other acute respiratory viral infections
In Russia and China, umifenovir is registered for treatment of influenza and other acute respiratory viral infections when started early in illness. Randomized, placebo-controlled trials (the ARBITR study in Russia and an earlier Chinese trial) found faster symptom resolution and shorter fever duration with umifenovir compared with placebo when treatment began within about 36 hours of symptom onset. This is a country-specific registered use, not a globally approved indication. (6) (7) (1) (5)
Prevention (prophylaxis) of influenza and ARVI in Russia
Russian product information also describes prophylactic use of umifenovir during periods of increased respiratory-infection risk. This dossier did not locate an independent randomized prevention trial to support this specific use; it is included here only as a labelled Russian use, not as trial-confirmed prevention. (1) (3)
Not an approved or evidence-supported treatment for COVID-19
Umifenovir was used off-label for COVID-19 in China, particularly in 2020-2021, but it is not an approved COVID-19 treatment anywhere. A systematic review and meta-analysis of 16 studies found no significant benefit over non-antiviral treatment for viral-clearance or clinical outcomes and a higher rate of adverse events (relative risk 2.24). A subsequent 2025 multicentre randomized controlled trial found no significant improvement in hospital stay, ICU admission, or mortality compared with standard care, and its authors concluded that routine use of umifenovir for COVID-19 is not currently justified. This page must not present umifenovir as a COVID-19 treatment. (8) (9)
Before taking umifenovir
Do not take / not appropriate for
- Do not take umifenovir if you have a known hypersensitivity/allergy to umifenovir or any ingredient of the exact product. (all products) (3) (5)
- Do not give umifenovir to a child younger than the minimum age stated on the exact product's local label. The minimum age differs by country, formulation, and source: Russian oral-suspension product information describes use from 2 years of age, another Russian reference describes non-use under 3 years, and Chinese product information states that no paediatric clinical research data exist in China for this medicine. Do not assume any single age threshold applies everywhere. (children) (2) (1) (5)
- Pregnancy and breastfeeding guidance differs by country. Russian product information for the oral-suspension product states umifenovir is contraindicated in the first trimester of pregnancy and during breastfeeding; a separate Russian reference describes it as contraindicated in pregnancy generally, with nursing discontinued if treatment is needed. Chinese product information instead states that efficacy and safety in pregnant or breastfeeding women have not been established. Do not use umifenovir in pregnancy or while breastfeeding unless a doctor who knows the exact product and country context specifically advises it. (pregnancy and breastfeeding) (2) (3) (5)
Tell your clinician about
- Whether you are pregnant, trying to become pregnant, or breastfeeding.
- The exact age of the person who will take it, since minimum-age rules differ by country and product.
- Any history of liver problems, since elevated liver enzymes have been reported as a side effect in clinical trials.
- Any known drug allergies, since rare allergic reactions and very rare anaphylaxis have been reported.
- All other medicines and supplements currently taken, since a comprehensive drug-interaction profile for umifenovir was not found in the sources reviewed for this dossier.
- Whether the illness could be COVID-19, since umifenovir is not an approved or evidence-supported COVID-19 treatment.
How to take umifenovir
- Umifenovir is taken by mouth. Some Russian product information directs dosing before meals; exact timing instructions vary by product, so follow the leaflet supplied with your exact product.
- The dose, number of times per day, and duration reported in the sources reviewed for this dossier differ by country: Russian clinical-trial dosing for adults used 200 mg four times daily for 5 days, while Chinese product information describes 200 mg three times daily for 5 days for adults. Do not choose between these regimens yourself.
- Do not start, stop, or change the dose or duration on your own. Follow the exact instructions on the product package or from your doctor or pharmacist for the country where the product was obtained.
- Treatment is generally started as early as possible after symptoms begin; trial evidence for benefit is strongest when treatment began within about 36 hours of symptom onset.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Missed dose
No specific missed-dose instructions were found in the authoritative sources reviewed for this dossier. If a dose is missed, contact a pharmacist or doctor for advice rather than doubling the next dose.
Overdose
No well-documented human overdose data were found in the sources reviewed for this dossier. If an overdose is suspected or a larger amount than directed has been taken, treat it as a medical emergency: contact a poison-control or emergency service, or seek urgent medical care immediately, and take the product packaging with you.
Side effects
Reported side-effect rates come mainly from randomized trials in influenza/ARVI treatment and from a Chinese regulator-referenced product label; a separate systematic review found a higher overall adverse-event rate when umifenovir was used off-label for COVID-19. Effects and their frequency may differ between indications, countries, and formulations.
Nausea, diarrhea, dizziness, or elevated liver enzymes (transaminases) on blood testing
What to notice: Chinese product-label data describe an overall adverse-event rate of approximately 6.2%, most often gastrointestinal symptoms, dizziness, or a laboratory finding of raised liver enzymes. Russian and Chinese randomized trials reported similar effects, generally described by investigators as mild and self-limiting.
What to do: Tell the prescribing clinician or pharmacist if symptoms are troublesome, persistent, or if you notice yellowing of the skin or eyes, dark urine, or unusual tiredness. (5) (6) (7)
Allergic skin reaction
What to notice: Itching, rash, or hives after taking umifenovir.
What to do: Contact a doctor or pharmacist promptly; stop the medicine if advised. (3)
Serious warnings
Anaphylaxis / severe allergic reaction — emergency
Symptoms: Wheezing or breathing difficulty, swelling of the face, lips, tongue, or throat, widespread hives, dizziness or fainting, or a rapid drop in blood pressure.
Action: Reported as very rare in Russian pharmacovigilance-referenced sources, but seek emergency care immediately if these symptoms occur after taking umifenovir. (3)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Other medicines, herbal products, and supplements (general) | A comprehensive, independently verified drug-interaction profile for umifenovir was not found in the authoritative sources reviewed for this dossier. One Russian professional reference states that no clinically significant interactions have been reported, but this reflects limited formal interaction study rather than confirmed safety with all other medicines. | Tell a doctor and pharmacist about all other medicines, herbal products, and supplements taken, since the interaction profile is not fully established. (3) |
Pregnancy, breastfeeding, kidney/liver function, age
Children
Minimum age for use differs by country, formulation, and source. Russian oral-suspension product information permits use from 2 years; a separate Russian reference describes non-use under 3 years; Chinese product information states that no paediatric clinical research data exist in China. Use only the exact age guidance on the specific product's label and a clinician's advice. (2) (1) (5)
Pregnancy and breastfeeding
Guidance differs by country. Russian product information describes contraindication in the first trimester of pregnancy and during breastfeeding for at least one product; a separate Russian reference describes contraindication throughout pregnancy. Chinese product information instead states that safety and efficacy in pregnancy and breastfeeding have not been established. Do not use during pregnancy or breastfeeding unless a doctor familiar with the exact product and country specifically advises it. (2) (3) (5)
Older adults (65 years and above)
Chinese product information explicitly states that safety in patients over 65 years has not been established. This dossier found no separate Russian data on older adults specifically. (5)
Kidney or liver impairment
No renal- or hepatic-impairment-specific dosing guidance was located in the authoritative sources reviewed for this dossier. Because elevated liver enzymes have been reported as a side effect in clinical trials, tell your doctor about any known liver problems before use; there is no established dose-adjustment rule to offer here.
Monitoring
Before starting
- Confirm the illness, its duration (trial benefit was strongest when treatment started within about 36 hours of symptom onset), and the exact age, pregnancy, and breastfeeding status of the person who will take it.
- Confirm the exact country-specific product, its labelled minimum age, and its exact dosing instructions before use.
During treatment
- Watch for gastrointestinal symptoms, dizziness, or signs of an allergic reaction.
- Consider that unexplained fatigue, yellowing of the skin or eyes, or dark urine could reflect the liver-enzyme changes reported in trials, and seek clinical assessment if these occur.
- Do not use umifenovir as a substitute for a confirmed COVID-19 treatment plan or for medical assessment of a worsening respiratory illness.
Storage
Store below 25°C, protected from moisture, in the original packaging, out of reach of children. Reconstituted oral-suspension/powder products in Russia are described as needing refrigeration at or below 8°C after mixing and use within 10 days. Exact storage requirements differ by product, formulation, and country, so follow the leaflet supplied with your exact product.
Professional information
Clinician-facing context only. Umifenovir is not FDA-, EMA-, or MHRA-approved; use the exact local product information and current clinical judgement for the country involved.
Russia
Indication: Influenza / acute respiratory viral infection, adult treatment (as used in the ARBITR randomized trial)
Dose summary: 200 mg orally four times daily (800 mg/day) for 5 days in adults, started within about 36 hours of symptom onset in the reference trial. Age-based paediatric oral-suspension dosing (10 mL/50 mg for ages 2-6, 20 mL/100 mg for ages 6-12, 40 mL/200 mg for age 12+ and adults) is described in Russian oral-suspension product information for a four-times-daily, 5-day regimen. Prophylactic regimens also exist in Russian product information but were not independently trial-verified in this dossier.
Renal context: No renal- or hepatic-impairment-specific adjustment was located in the sources reviewed for this dossier. (6) (2)
China
Indication: Influenza / acute respiratory viral infection, adult treatment
Dose summary: 200 mg (0.2 g) orally three times daily (600 mg/day) for 5 days in adults, per Chinese product information referenced against a 2022 National Medical Products Administration (NMPA) label-revision announcement covering tablet, dispersible tablet, granule, and capsule formulations. No paediatric clinical research data exist in China per the same product information; safety in patients over 65 years is described as not established.
Renal context: No renal- or hepatic-impairment-specific adjustment was located in the sources reviewed for this dossier. (5) (4)
Hepatic guidance
No hepatic-impairment-specific dosing guidance was located. Elevated transaminases have been reported as a treatment-emergent finding in clinical trials; baseline and monitoring liver function assessment may be prudent, but no dose-adjustment protocol is established in this dossier's evidence base.
Overdose note
No human overdose case data were located in the sources reviewed for this dossier. Manage suspected overdose as a medical emergency with supportive care and poison-centre or specialist advice; no specific antidote is described in the evidence reviewed. (1) (3) (4)
Frequently asked questions
Is umifenovir (Arbidol) approved by the FDA?
No. Umifenovir is not approved by the US FDA, the European Medicines Agency, or the UK MHRA. It is registered as a pharmaceutical product in Russia and China. (1) (4)
Does umifenovir treat COVID-19?
No well-supported evidence shows a clinically important benefit for COVID-19. A systematic review of 16 studies found no significant benefit over non-antiviral treatment and more adverse events, and a 2025 randomized trial concluded that routine use for COVID-19 is not currently justified. Umifenovir is not an approved COVID-19 treatment. (8) (9)
Can children take umifenovir?
It depends on the country and product. Some Russian oral-suspension product information allows use from 2 years old, while Chinese product information states there is no paediatric research data in China. Follow the exact product label and a clinician's advice for the child's age and country. (2) (5)
Is umifenovir the same as oseltamivir (Tamiflu)?
No. They are different medicines with different mechanisms of action and different, separately established evidence bases. Umifenovir's dosing, safety data, and country approvals should not be assumed to match oseltamivir or any other antiviral.
What is the mechanism of action of umifenovir?
Umifenovir is proposed to act as a viral membrane-fusion inhibitor, interacting with viral hemagglutinin and blocking fusion of the viral lipid envelope with the host-cell membrane; it has also been described as having interferon-inducing and immunomodulatory properties (including effects on T-cell proliferation and macrophage function) in Russian pharmacological reference material. Reported elimination half-life is approximately 17-21 hours, with roughly 40% excreted unchanged via bile according to a Russian drug-reference source. This dossier did not independently verify these pharmacokinetic figures against a primary regulator source. (1) (3) (4)
References
- Umifenovir (Умифеновир) drug reference monographVidal.ru (Russian professional drug reference / recognised national pharmacy database) · Russia · accessed 2026-07-23 · source 1
- Arbidol powder for oral suspension — official package insertmedi.ru, hosting the Pharmstandard-issued official package insert (инструкция по применению) · Russia · accessed 2026-07-23 · source 2
- Umifenovir (Умифеновир) active-substance monographRLSNET.ru (Register of Medicines of Russia, recognised national pharmacy database) · Russia · accessed 2026-07-23 · source 3
- Announcement No. 5 of 2022 on revising Arbidol (umifenovir hydrochloride) formulation package insertsChina National Medical Products Administration (NMPA) — national regulator · China · dated 2022-01-17 · accessed 2026-07-23 · source 4
- Arbidol hydrochloride granules (盐酸阿比多尔颗粒, brand Zhuangtong/壮彤) product instructions39药品通 (39 Yaopintong), hosting manufacturer product-instruction text for a specific NMPA-registered product · China · accessed 2026-07-23 · source 5
- Pshenichnaya et al., "Clinical efficacy of umifenovir in influenza and ARVI (study ARBITR)", Terapevticheskii Arkhiv, 2019PubMed (NLM) abstract of a peer-reviewed randomized controlled trial · Russia · dated 2019 · accessed 2026-07-23 · source 6
- Wang et al., randomized double-blind placebo-controlled trial of Arbidol in naturally acquired influenza, Zhongguo Yi Xue Ke Xue Yuan Xue Bao, 2004PubMed (NLM) abstract of a peer-reviewed randomized controlled trial · China · dated 2004 · accessed 2026-07-23 · source 7
- Amani et al., "Efficacy and safety of arbidol (umifenovir) in patients with COVID-19: A systematic review and meta-analysis", Immunity, Inflammation and Disease, 2021PubMed Central full-text, peer-reviewed systematic review and meta-analysis · international · dated 2021 · accessed 2026-07-23 · source 8
- Multicentre, open-label, randomized controlled phase-3 trial of umifenovir for COVID-19PubMed Central full-text, peer-reviewed randomized controlled trial · international · dated 2025-01-31 · accessed 2026-07-23 · source 9
- Umifenovir (International database)Drugs.com International Drug Name Database (aggregator) · international · accessed 2026-07-23 · source 10
Brand names by country
Single-ingredient umifenovir names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.