ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.
Overview
It's for people with mild memory problems and confirmed amyloid; regular MRI scans check for brain swelling or bleeding.
What it's used for
- Mild cognitive impairment or mild dementia from Alzheimer's disease
How to take it
- Given by IV every 2 weeks in a clinic.
- Keep all MRI appointments.
Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.
Side effects
Common side effects
- Infusion reactions
- Headache
Call 911Confusion, severe headache, vision changes, seizures, or trouble walking (possible brain swelling or bleeding)
Warnings
- Boxed warning: brain swelling and bleeding (ARIA), higher with two copies of the APOE4 gene.
Other medicines, foods, and alcohol
- Blood thinners may raise bleeding risk.
Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.
Pregnancy and breastfeeding
Not relevant.
Missed doses, overdose, and storage
If you miss a dose
Call your clinic to reschedule.
If someone takes too much
Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.
Storing it
Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.
Conditions it's used for
Sources
- DailyMed: FDA drug label for Lecanemab (U.S. National Library of Medicine)
- MedlinePlus: Drugs, herbs, and supplements
- FDA: Drugs@FDA
Last updated 2026-11-13.