Ritlecitinib
Ritlecitinib (LITFULO) is a prescription medication used to treat severe alopecia areata in adults and adolescents aged 12 years and older. It works by irreversibly inhibiting specific enzymes (JAK3 and TEC kinases) involved in immune signaling, thereby reducing the immune attack on hair follicles that causes hair loss.
A kinase inhibitor that treats severe alopecia areata by targeting immune pathways involved in hair follicle inflammation.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- L04AF08
- RxNorm
- 2641595
- Generic
- Ritlecitinib
- Class
- atc-l04
- Brands
- Litfulo
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Ritlecitinib is FDA-approved for the treatment of severe alopecia areata in adults and adolescents 12 years of age and older. Alopecia areata is an autoimmune condition that causes patchy or complete hair loss.
Ritlecitinib is a kinase inhibitor that irreversibly blocks Janus kinase 3 (JAK3) and the TEC kinase family by binding to their adenosine triphosphate (ATP) sites. This action inhibits inflammatory cytokine signaling pathways that drive the autoimmune attack on hair follicles.
As a JAK inhibitor, ritlecitinib may increase the risk of infections, including serious infections. Common side effects may include headache, diarrhea, and acne. Patients should discuss vaccination history and potential drug interactions with their healthcare provider before starting treatment. Regular monitoring may be required during therapy.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy