Emicizumab: uses, dosing, side effects & brands
Emicizumab is a medicine sold in the U.S. under one brand, for hemophilia a. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Hemophilia A
- Available as
- Injectable
- Sold as
- Hemlibra
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Boxed warning
- Boxed warning
How emicizumab is dosed
From the FDA label for Hemlibra (application BLA761083). Other emicizumab products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Recommended loading dose is 3 mg/kg by subcutaneous injection once weekly for the first 4 weeks, followed by a maintenance dose of: 1.5 mg/kg once every week, or 3 mg/kg once every two weeks, or 6 mg/kg once every four weeks. ( 2.1 ) See Full Prescribing Information for important preparation and administration instructions. ( 2.2 ) 2.1 Recommended Dosage For subcutaneous use only. The recommended loading dose is 3 mg/kg by subcutaneous injection once weekly for the first 4 weeks, followed by a maintenance dose of: 1.5 mg/kg once every week, or 3 mg/kg once every two weeks, or 6 mg/kg once every four weeks. The selection of a maintenance dose should be based on healthcare provider preference with consideration of regimens that may increase patient adherence. Discontinue the prophylactic use of bypassing agents the day before starting HEMLIBRA prophylaxis. The prophylactic use of factor VIII (FVIII) products may be continued during the first week of HEMLIBRA prophylaxis. Missed Dose If a dose of HEMLIBRA is missed administer as soon as possible and then resume usual dosing schedule. Do not administer two doses on the same day to make up for a missed dose. 2.2 Preparation and Administration HEMLIBRA is intended for use under the guidance of a healthcare provider. After proper training in subcutaneous injection technique, a patient may self-inject, or the patient's caregiver may…
Emicizumab side effects
The following serious adverse reactions are described elsewhere in the labeling: Thrombotic Microangiopathy Associated with HEMLIBRA and aPCC [see Warnings and Precautions (5.1) ] Thromboembolism Associated with HEMLIBRA and aPCC [see Warnings and Precautions (5.2) ] Most common adverse reactions (incidence ≥ 10%) are injection site reactions, headache, and arthralgia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following adverse reactions are based on pooled data from two randomized trials in adult and adolescent patients (HAVEN 1 and HAVEN 3), one single-arm trial in adult and adolescent patients (HAVEN 4), one single-arm trial in pediatric patients (HAVEN 2), and one dose-finding trial, in which a total of 391 male patients with hemophilia A received at least one dose of HEMLIBRA as routine prophylaxis. Two hundred eighty-one patients (72%) were adults (18 years and older), 50 (13%) were adolescents (12 years up to less than 18 years), 55 (14%) were children (2 years up to less than 12 years),…
Who shouldn’t take emicizumab
None. None ( 4 )
Emicizumab drug interactions
7.1 Hypercoagulability with Concomitant Use of aPCC Clinical experience suggests that a drug interaction exists with HEMLIBRA and aPCC [see Warnings and Precautions (5.1 , 5.2) ] . 7.2 Drug-Laboratory Test Interactions HEMLIBRA restores the tenase cofactor activity of missing activated factor VIII (FVIIIa). Coagulation laboratory tests based on intrinsic clotting (i.e., aPTT) measure the total clotting time including time needed for activation of FVIII to FVIIIa by thrombin. Such intrinsic pathway-based tests will yield overly shortened clotting times with HEMLIBRA, which does not require activation by thrombin. The overly shortened intrinsic clotting time will then disturb all single-factor assays based on aPTT, such as the one-stage FVIII activity assay; however, single-factor assays utilizing chromogenic or immuno-based methods are unaffected by HEMLIBRA and may be used to monitor coagulation parameters during treatment, with specific considerations for FVIII chromogenic activity assays as described below. Chromogenic FVIII activity tests may be manufactured with either human or bovine coagulation proteins. Assays containing human coagulation factors are responsive to HEMLIBRA but may overestimate the clinical hemostatic potential of HEMLIBRA. In contrast, assays containing bovine coagulation factors are insensitive to HEMLIBRA (no activity measured) and can be used to monitor endogenous or infused FVIII activity, or to measure anti-FVIII inhibitors. HEMLIBRA remains active in the presence of inhibitors against FVIII, so it will produce a false-negative result in clotting-based Bethesda assays for functional inhibition of FVIII. Instead, a chromogenic Bethesda assay utilizing a bovine-based FVIII chromogenic test that is insensitive to HEMLIBRA may be used. Due to the long half-life of HEMLIBRA, effects on coagulation assays may persist for up to 6 months after the last dose [see Clinical Pharmacology (12.3) ] .
Every emicizumab product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Hemlibra.
Emicizumab and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for emicizumab: levels in milk, effects in breastfed infants, and the drugs it would consider insteadA low level of emicizumab was found in the milk of 2 women. The drug is likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. One infant was breastfed for 2 months starting at 4 months of age during maternal therapy with no obvious adverse reaction. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.
National Institute of Child Health and Human Development, record revised July 15, 2026. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about emicizumab
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 975 reports naming emicizumab, and the FDA flagged 71% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- haemarthrosis120 reports
- haemorrhage106 reports
- haematoma38 reports
- muscle haemorrhage30 reports
- fall29 reports
- arthralgia28 reports
- headache24 reports
- anti factor viii antibody positive22 reports
Read these as a signal, not a rate. A report does not mean emicizumab caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is emicizumab?
Hemlibra (Emicizumab) is a medication used to treat Hemophilia A.
Can you take emicizumab with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run emicizumab against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does emicizumab come in?
Across the brands we track, emicizumab is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic emicizumab?
We do not currently list a generic-labelled emicizumab product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Emicizumab: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/emicizumab
- MLA
- “Emicizumab: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/emicizumab.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for emicizumab on DailyMed (NIH) ↗ — including its boxed warning in full.