What are the FDA-approved treatments for Alzheimer’s disease in 2025 and how do they differ from alternative therapies?
Executive summary
As of 2025, the FDA has approved anti-amyloid monoclonal antibodies—lecanemab (Leqembi) and donanemab (Kisunla)—for adults with early Alzheimer’s disease (mild cognitive impairment or mild dementia) and these agents are the first medicines shown to slow clinical decline by removing brain amyloid [1] [2] [3]. Symptom-focused drugs (cholinesterase inhibitors and memantine), a donepezil skin patch and an antipsychotic for severe agitation remain in use; non‑drug and alternative therapies (exercise, diet, supplements, herbal products, bright‑light therapy) are widely promoted but lack the same regulatory evidence base [4] [5] [6] [7].
1. New disease‑modifying drugs: the amyloid antibodies that changed the standard of care
The regulatory pivot in 2023–2024 culminated in FDA conversion of lecanemab’s approval to traditional approval after a confirmatory Phase 3 trial showed clinical benefit, and the agency has approved donanemab for early Alzheimer’s; both are antibodies that target and reduce amyloid plaques and protofibrils in people with biomarker‑confirmed disease and are intended for patients with mild cognitive impairment or mild dementia due to Alzheimer’s [1] [2] [3].
2. How these drugs work and what their trials showed
Lecanemab and donanemab are monoclonal antibodies directed at forms of amyloid‑beta; their development used biomarkers (amyloid PET or CSF) to identify patients and to demonstrate target engagement—plaque removal—correlated with a modest but measurable slowing of cognitive decline in randomized trials [8] [1] [2].
3. Practical differences and dosing updates in 2025
Lecanemab’s label specifies initiation in early disease and, by 2025, the FDA approved less‑frequent IV maintenance dosing and a subcutaneous weekly autoinjector option for maintenance after initial treatment, increasing convenience and at‑home use (Leqembi IV every four weeks and a weekly subcutaneous autoinjector were approved in 2025) [9] [10] [11]. Donanemab remains an IV anti‑amyloid option approved for the same early stages [3] [12].
4. Safety, limitations and eligibility constraints
Regulatory materials and reporting emphasize that these antibodies carry safety risks—most notably amyloid‑related imaging abnormalities (ARIA), including brain swelling and bleeding—and trials excluded people beyond early disease stages; labels and guidance therefore restrict use to patients with confirmed amyloid pathology and early symptomatic disease [1] [3] [9].
5. Symptom‑relief drugs still part of routine care
Traditional symptomatic agents—cholinesterase inhibitors and memantine—continue to be prescribed for cognitive symptoms; the field also added formulation advances such as a once‑weekly donepezil skin patch (Adlarity) and an FDA clearance of brexpiprazole (Rexulti) for severe agitation connected to Alzheimer’s [4] [5].
6. Alternative and non‑pharmacological therapies: what they offer and what they don’t
Non‑drug interventions—exercise, cognitive rehabilitation, occupational therapy, bright‑light therapy and behavioral strategies—are recommended to improve function and quality of life but do not have the disease‑modifying evidence required for FDA approval [13] [7]. Herbal remedies, dietary supplements and “medical foods” are widely marketed; reviews identify many phytoconstituents with preclinical promise but clinical trial results are inconsistent and larger, longer studies are needed [14] [6].
7. Competing perspectives and the research agenda
Researchers and agencies acknowledge the breakthrough represented by anti‑amyloid antibodies while warning that amyloid‑only approaches may be insufficient; many experts and trials now pursue combination strategies (anti‑amyloid plus anti‑tau, anti‑inflammation or neuroprotective agents) and better access/diagnosis in primary care settings [15] [16] [17].
8. Money, access and implicit agendas to watch
Manufacturers and health systems are expanding delivery and maintenance options (home autoinjectors, maintenance dosing changes) that can improve access but also align with commercial interests; payers and Medicare policies require real‑world data collection, reflecting both safety surveillance needs and cost‑control priorities [10] [3].
Limitations: available sources do not mention any FDA approvals beyond lecanemab and donanemab in 2025, nor do they provide long‑term real‑world effectiveness beyond trial and early post‑approval data (not found in current reporting).