Ritlecitinib (Litfulo) for Alopecia Areata Hair Loss
Last reviewed on 6 August 2026. We review our treatment guides every six months to keep them accurate.
Ritlecitinib, sold under the brand name Litfulo, is a prescription-only medicine for severe alopecia areata. The most important thing to understand about it is what it actually treats. Alopecia areata is an autoimmune condition, in which the immune system mistakenly attacks the hair follicles and causes patchy hair loss. Ritlecitinib is a treatment for that condition. It is not a treatment for male or female pattern baldness, the common genetic kind of thinning, and it is not a general hair loss pill.
Ritlecitinib is an oral JAK inhibitor, taken as a once-daily capsule, and it was developed by Pfizer. It is a specialist medicine that is started and monitored by a dermatologist, and in Great Britain it is available on the NHS for severe alopecia areata in people aged 12 and over. This guide explains what ritlecitinib is, how it works, whether it is on the NHS, how well it works, who can take it, its side effects, and whether it is a cure. For the official UK position, the National Institute for Health and Care Excellence sets out its NHS recommendation in NICE guidance TA958, and the Litfulo Summary of Product Characteristics is the manufacturer's approved information. Both are kept up to date between our own reviews.
Ritlecitinib is for alopecia areata, not pattern baldness
Ritlecitinib is licensed only for severe alopecia areata, an immune-driven condition; it has no role in male or female pattern (genetic) baldness.
This distinction matters more than any other on this page. Ritlecitinib is licensed only for severe alopecia areata, which is driven by the immune system. It works by calming that immune attack, so it has no role in the ordinary, hereditary hair loss that most people mean by baldness. If your hair loss follows the familiar pattern of a receding hairline or thinning crown, ritlecitinib is not the treatment for it, and the medicines usually considered there are different. You can read more about the condition itself in our guide to alopecia areata, and about why there is still no single fix for genetic hair loss in our guide on the cure for baldness.
How ritlecitinib works
In alopecia areata, immune cells send signals that lead them to attack the hair follicles, which switches off hair growth and causes the hair to fall out in patches. Ritlecitinib belongs to a group of medicines called JAK inhibitors. It blocks two of the enzyme systems that carry those immune signals, an enzyme called JAK3 and a related family known as the TEC kinases, both of which are involved in the process that damages the follicles. By dampening that signalling, ritlecitinib eases the immune attack and gives the follicles the chance to start producing hair again.
Because it acts on the immune system rather than on the follicle directly, ritlecitinib does not work overnight. Any regrowth is gradual and measured over months, and a specialist reviews whether it is helping before deciding to continue. It is also a treatment rather than a cure, a point we return to below.
Is ritlecitinib available on the NHS?
Yes, for the right patients. The National Institute for Health and Care Excellence recommended ritlecitinib in its guidance TA958, published in March 2024, as an option for treating severe alopecia areata in people aged 12 and over. That recommendation means it is available on the NHS for that group, within its licence and under specialist care. It is a hospital specialist medicine, so it is started and supervised by a dermatologist rather than prescribed by a GP, and it is intended for severe disease rather than milder, limited patches. The usual route is to see your GP first, who can refer you to a dermatology service where suitability is assessed.
Does ritlecitinib work? What the trials show
It helps a meaningful proportion of people, but not everyone, and the results build slowly. The main evidence comes from a large international trial called ALLEGRO, in which adults and adolescents with severe alopecia areata took ritlecitinib or a dummy capsule. After 24 weeks, about 1 in 4 of those on the licensed dose had regrown enough hair to have 80 per cent or more scalp coverage, compared with about 1 in 50 taking the dummy capsule. Responses continued to improve for those who kept taking it up to 48 weeks, and, as DermNet notes, over a longer period of up to about two years close to half of those treated may reach that level of coverage, with around half of those responders regaining most or all of their hair.
Two honest caveats go with those figures. Regrowth takes months, so the before and after pictures people search for reflect many months of treatment, not a quick change, and a specialist judges the response over that time. And a proportion of people do not respond at all, which is why the benefit is reviewed and treatment may be stopped if it is not helping.
Who can take ritlecitinib?
It is licensed for adults and adolescents aged 12 and over with severe alopecia areata. Whether it is suitable for a particular person is a decision for a dermatologist, who weighs the severity of the hair loss against the medicine's risks and checks for anything that would make it unsafe. It is not recommended in pregnancy or while breastfeeding, and women who could become pregnant are advised to use effective contraception during treatment. Because it acts on the immune system, your specialist will ask about infections, your vaccination history and any other conditions or medicines before starting it. It is important to give a full picture of your health so the right decision can be made.
Side effects and safety
Ritlecitinib is a powerful medicine that needs specialist screening and monitoring, so its safety deserves a careful account rather than a reassuring one. The more common side effects reported in trials include headache, diarrhoea, acne, inflamed hair follicles, an itchy rash or hives, dizziness, and infections such as colds and other upper respiratory infections. Shingles, caused by reactivation of the chickenpox virus, is also recognised and is one reason vaccinations are reviewed before treatment.
As a JAK inhibitor, ritlecitinib also carries the class-wide cautions that apply to this group of medicines. These include a risk of serious infections, blood clots, major cardiovascular events such as heart attack and stroke, certain cancers including non-melanoma skin cancer, and changes in blood cell counts. For that reason a specialist screens for infections such as tuberculosis and hepatitis and checks blood counts before starting, makes sure vaccinations are up to date, avoids live vaccines around the time of treatment, and monitors during treatment. The UK medicines regulator, the MHRA, advises extra caution with JAK inhibitors in people aged 65 and over, current or long-term smokers, and those at higher risk of cardiovascular disease or cancer. None of this is a reason to be alarmed, but it is why the medicine is prescribed and monitored by a specialist and why you should report any new symptoms to them.
Is ritlecitinib a cure for alopecia areata?
No. Ritlecitinib manages the condition rather than curing it. It can calm the immune attack and allow hair to regrow while it is being taken, but it does not switch off the underlying tendency for alopecia areata to occur, and hair that has regrown can be lost again if the medicine is stopped. For many people that still makes it a valuable option, but it is best understood as an ongoing treatment that a specialist reviews over time, not a one-off fix.
Frequently asked questions
Is ritlecitinib available on the NHS?
Yes. NICE recommends it (guidance TA958, March 2024) for severe alopecia areata in people aged 12 and over, so it is available on the NHS for that group, within its licence and under specialist care. It is started by a dermatologist, usually after a referral from your GP, rather than prescribed directly by a GP.
Is ritlecitinib for pattern baldness?
No. It is licensed only for severe alopecia areata, an autoimmune condition. It works by calming an immune attack on the follicles, so it has no role in male or female pattern baldness, which is the common hereditary kind of hair loss and is treated in other ways.
Does ritlecitinib work, and what do before and after results look like?
It helps a meaningful proportion of people, but the change is gradual over months, not sudden. In the ALLEGRO trial, about 1 in 4 people on the licensed dose had 80 per cent or more scalp coverage by 24 weeks, compared with about 1 in 50 on a dummy capsule, and results continued to improve with longer treatment. Not everyone responds, so any before and after photographs reflect many months of treatment in people who did respond.
What age can take ritlecitinib?
It is licensed for adults and adolescents aged 12 and over with severe alopecia areata. Whether it is suitable for any individual is decided by a dermatologist.
What are the side effects of ritlecitinib?
Common side effects include headache, diarrhoea, acne, inflamed hair follicles, rash or hives, dizziness and infections such as colds, along with shingles. As a JAK inhibitor it also carries class-wide cautions about serious infections, blood clots, major cardiovascular events, certain cancers and changes in blood counts, which is why a specialist screens and monitors people taking it. Report any new symptoms to your specialist.
Is ritlecitinib a cure?
No. It manages the condition and can allow hair to regrow while it is taken, but it does not cure alopecia areata, and regrowth can be lost if the medicine is stopped. A specialist reviews whether to continue it over time.
Is Litfulo the same as ritlecitinib?
Yes. Litfulo is the brand name for ritlecitinib, made by Pfizer. It is the same medicine.
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