Emicizumab
Emicizumab is an antibody medicine, given as an injection under the skin, that helps prevent or reduce bleeding episodes in people with hemophilia A.
🧬 Where this information comes from
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Emicizumab (Hemlibra) is a specialist antibody, injected under the skin, that prevents bleeding episodes in hemophilia A by bridging two clotting proteins (activated factor IX and factor X) to do the missing factor VIII's job; on the market since about 2017, it is a widely used prevention option, including for people with factor VIII inhibitors (antibodies that block factor replacement). Most people tolerate it well, mainly noticing injection-site redness, itching or soreness, plus occasional headache or joint pain. The boxed warning covers aPCC (activated prothrombin complex concentrate, a bleed treatment), since large amounts given alongside it have caused dangerous clots and thrombotic microangiopathy, small-vessel damage that can injure the kidneys.
Clinical pearls
- Tell every provider, lab and emergency team you use it, because it throws off clotting tests such as aPTT and ACT.
- The aPCC clotting risk can last up to 6 months after your last dose, so mention it even after stopping.
- It prevents bleeds but does not treat one already happening, so keep your hemophilia team's breakthrough-bleed plan handy.
- Call your care team if breakthrough bleeds become more frequent, since antibodies against it can rarely make it work less well.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Using aPCC (activated prothrombin complex concentrate) while on Hemlibra can cause serious blood clotting problems. These include thrombotic microangiopathy (damage to small blood vessels that can hurt the kidneys and lower platelets) and thromboembolism (dangerous blood clots).
This was seen when a large amount of aPCC was given for 24 hours or more to people on Hemlibra prevention. Your provider should monitor you if aPCC is used. If symptoms occur, aPCC is stopped and Hemlibra dosing is paused. Seek medical help right away if you have signs of clots or kidney trouble.
Patient Information Guide A plain-language walkthrough of Emicizumab, written from its FDA label.
What Emicizumab Is Used For
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Emicizumab is used to prevent bleeding in hemophilia A.
- Hemlibra is used as routine prophylaxis to prevent or reduce bleeding episodes in adults and children, newborn and older, with hemophilia A (congenital factor VIII deficiency).
- This includes people with or without factor VIII inhibitors.
How Emicizumab Works
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Emicizumab is a bispecific antibody. It bridges activated factor IX and factor X, which are clotting proteins.
This restores the function of the missing activated factor VIII that blood needs for effective clotting.
Emicizumab Dosage
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Hemlibra is injected under the skin. Treatment starts with weekly doses for 4 weeks, then continues weekly, every two weeks, or every four weeks, based on your provider's choice. The label does not tie it to meals.
- Bypassing agents used for prevention are stopped the day before starting. Factor VIII prevention may continue during the first week.
- If you miss a dose, give it as soon as possible, then go back to your usual schedule. Never take two doses on the same day to catch up.
- Rotate injection sites. Avoid moles, scars, and skin that is tender, bruised, red, hard, or broken.
- Throw away any unused medicine left in the single-dose vial.
Dosing details from the FDA-approved label
From the Emicizumab prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Prophylaxis (recommended dosage; subcutaneous use only)
- Loading dose 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
- Maintenance dose selection based on healthcare provider preference with consideration of regimens that may increase patient adherence
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION 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 administer HEMLIBRA, if a healthcare provider determines that it is appropriate. Self-administration is not recommended for children less than 7 years of age. The HEMLIBRA "Instructions for Use" contains more detailed instructions on the preparation and administration of HEMLIBRA [see Instructions for Use ] . Visually inspect HEMLIBRA for particulate matter and discoloration before administration. HEMLIBRA for subcutaneous administration is a colorless to slightly yellow solution. Do not use if particulate matter is visible or product is discolored. A syringe, a transfer needle with filter and an injection needle are needed to withdraw HEMLIBRA solution from the vial and inject it subcutaneously. Refer to the HEMLIBRA " Instructions for Use " for handling instructions when combining vials. Do not combine HEMLIBRA vials of different concentrations (i.e. 30 mg/mL and 150 mg/mL) in a single injection.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Emicizumab Side Effects
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Most side effects are mild to moderate.
Common side effects
- Injection site reactions (redness, pain, itching, bruising, swelling)
- Headache
- Joint pain (arthralgia)
- Fever
- Diarrhea
When to get medical help
- Get medical help right away if you have symptoms of a blood clot or thrombotic microangiopathy after using aPCC (a bypassing agent) while on Hemlibra.
- Call your care team if you notice more breakthrough bleeding than usual, which could mean the medicine is working less well.
- Tell your provider about any bleeding or clotting problems, or signs of kidney problems, especially after any aPCC use.
Serious problems involve clotting and kidney injury, mainly when aPCC is also used. Get medical help right away for those symptoms.
Emicizumab Warnings and Precautions
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- Clotting problems with aPCC: thrombotic microangiopathy and thromboembolism have occurred. The risk may last up to 6 months after the last dose.
- Antibodies: rarely, they reduce how well Hemlibra works. Watch for more breakthrough bleeding.
- Lab test interference: some clotting tests, such as aPTT and ACT, give unreliable results.
Emicizumab Interactions
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The main interaction is with aPCC.
- aPCC: raises the risk of serious clotting and kidney problems.
- Clotting lab tests (aPTT-based): Hemlibra distorts results, and this may last up to 6 months after the last dose.
- Bypassing agents: stopped the day before starting Hemlibra prevention.
Interactions listed in the FDA-approved label
From the Emicizumab prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Activated prothrombin complex concentrate (aPCC): Clinical experience suggests that a drug interaction exists with HEMLIBRA and aPCC, with hypercoagulability. See Warnings and Precautions (5.1, 5.2).
- Coagulation laboratory tests based on intrinsic clotting (e.g., aPTT) and aPTT-based single-factor assays such as the one-stage FVIII activity assay: HEMLIBRA yields overly shortened clotting times, which disturbs these assays; effects on coagulation assays may persist for up to 6 months after the last dose. Single-factor assays utilizing chromogenic or immuno-based methods are unaffected by HEMLIBRA and may be used to monitor coagulation parameters.
- Chromogenic FVIII activity assays containing human coagulation factors: Responsive to HEMLIBRA but may overestimate the clinical hemostatic potential of HEMLIBRA.
- Chromogenic FVIII activity assays containing bovine coagulation factors: Insensitive to HEMLIBRA (no activity measured). Can be used to monitor endogenous or infused FVIII activity, or to measure anti-FVIII inhibitors.
- Clotting-based Bethesda assays for functional inhibition of FVIII: HEMLIBRA remains active in the presence of FVIII inhibitors, so it produces a false-negative result. A chromogenic Bethesda assay utilizing a bovine-based FVIII chromogenic test that is insensitive to HEMLIBRA may be used instead.
Read the label’s full interactions text
7 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) ] .
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before Taking Emicizumab
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- There are no contraindications listed.
- Pregnancy: use only if the benefit outweighs the risk. Contraception is advised for women who could become pregnant.
- Breastfeeding: discuss benefits and risks with your provider.
- Children: approved from newborns up. Self-injection is not recommended under 7.
- Older adults: too few were studied to know if they respond differently.
- Severe liver or kidney impairment has not been studied.
How Your Body Processes Emicizumab
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After injection under the skin, Hemlibra is well absorbed, with bioavailability of about 80% to 93%. Injecting into the abdomen, upper arm, or thigh gives similar results.
It stays in the body a long time, with an elimination half-life of about 27 days. That is why its effects on lab tests and its aPCC interaction can last for months after the last dose.
How to Store Emicizumab
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Store HEMLIBRA vials in a refrigerator at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Do not freeze. stored out of and then returned to refrigeration.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Emicizumab: Pharmacist Answers to Common Questions
Quick, plain-English answers to the questions patients ask most about Emicizumab — the kind of thing our pharmacy team would talk through with you at the counter.
What is this medicine for?
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How do I take it?
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What side effects should I expect?
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Is there anything I should avoid using with it?
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Can I give the injections myself?
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What if I am pregnant or planning to be?
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Is Emicizumab available over the counter?
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When was Emicizumab first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More About Emicizumab on HelloPharmacist
Emicizumab Forms and Strengths (How It Comes)
Emicizumab is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Emicizumab inactive ingredients by manufacturer.
Injection
How this form is used
- Hemlibra is used for routine prophylaxis to prevent or reduce bleeding episodes in people with hemophilia A, with or without factor VIII inhibitors.
- Hemlibra is for subcutaneous use only.
- Hemlibra may be self-injected or given by a caregiver after training, if a provider agrees; self-injection is not recommended for children under 7.
- Hemlibra injections should be rotated to a different site each time, and upper outer arm injections should be given only by a caregiver or healthcare provider.
- Hemlibra should be checked before use and not used if the solution has particles or is discolored.
Emicizumab on the U.S. Market: Products, Makers and Brands
How Emicizumab appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 6 Emicizumab product records with the FDA, mostly as injection; the earliest marketing or approval year on record is 2017. Brand names on the directory include Hemlibra; the rest are generics.
Also listed with the FDA, not a patient dose form: Unfinished injection, solution (6) · Unfinished solution (4) · Unfinished liquid (1) — bulk drug substance and unfinished product sold to compounders and other manufacturers to finish, and multi-item kits. These aren’t counted in the dose-form total above.
How Widely Emicizumab Is Used (Medicaid Data)
A general measure of how commonly Emicizumab is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Emicizumab is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Emicizumab prescribed? Of the 1,603 medications we measure, Emicizumab ranks #756 by Medicaid prescriptions — more than 53% of them.
Utilization by Emicizumab product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
0.4 ML emicizumab-kxwh 150 MG/ML Injection Most dispensed
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1989814
0.7 ML emicizumab-kxwh 150 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1989809
1 ML emicizumab-kxwh 150 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1989816
2 ML emicizumab-kxwh 150 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2632728
1 ML emicizumab-kxwh 30 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1989799
0.4 ML emicizumab-kxwh 30 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2675567
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Emicizumab, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 6 of 6 listed Emicizumab NDCs with Medicaid activity.
Compare Emicizumab Products
A representative set of FDA-listed product records for Emicizumab — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 12 mg/0.4 mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
| 30 mg/mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
| 60 mg/0.4 mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
| 105 mg/0.7 mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
| 150 mg/mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
| 300 mg/2 mL | Subcutaneous | Genentech, Inc. | BLA | View NDC → |
Showing 6 of 6 products — FDA National Drug Code Directory. See every product, package size and price: browse all 6 Emicizumab NDCs →
Emicizumab Side Effects Reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Emicizumab — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Emicizumab in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Emicizumab FDA Approval History
How Emicizumab went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Emicizumab Recall History
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Emicizumab recalls since July 2021.
✅No Emicizumab recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Oct 8, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 1989794 1 dose form · 6 strengths
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Dose form (SCDF) Injection RxCUI 1989798In current FDA listingsClinical drug / strength (SCD) 0.4 ML emicizumab-kxwh 150 MG/MLRxCUI 19898140.4 ML emicizumab-kxwh 30 MG/MLRxCUI 26755670.7 ML emicizumab-kxwh 150 MG/MLRxCUI 19898091 ML emicizumab-kxwh 150 MG/MLRxCUI 19898161 ML emicizumab-kxwh 30 MG/MLRxCUI 19897992 ML emicizumab-kxwh 150 MG/MLRxCUI 2632728
Look up RxCUI 1989794 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Emicizumab Supply and Shortage Status
Whether Emicizumab is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Emicizumab Brand Names
Emicizumab is sold under one brand name in the FDA directory — Hemlibra. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who Makes Emicizumab: Manufacturers and Labelers
One company lists Emicizumab products with the FDA. By number of product records, the largest are Genentech, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Emicizumab Drug Class (RxNorm)
Emicizumab belongs to the Other systemic hemostatics class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for This Emicizumab Page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Genentech, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →