Medication

Klisyri (Tirbanibulin)

Klisyri is a five-day ointment for actinic keratoses on the face and scalp. The short course and the comparatively mild reaction are the whole point of it. The cost is the catch — it is brand-only and expensive next to generic 5-fluorouracil.
At a Glance

Klisyri (tirbanibulin) is a 1% ointment for actinic keratoses on the face or balding scalp. It is applied once a day for five consecutive days and nothing else — the shortest course of any field treatment for sun damage. Redness, flaking and crusting follow, peaking about a week in and usually settling within two to three weeks. It is milder and far shorter than 5-fluorouracil, but it is limited to the face and scalp, it has no generic, and it costs considerably more.

Key Facts

AKAtirbanibulin ointment 1%
Drug ClassMicrotubule inhibitor (it blocks the internal scaffolding cells need to divide)
Rx or OTCPrescription only
Typical CourseOnce daily for 5 consecutive days, one unit-dose packet per day
Typical Strength1% ointment, on a treatment field of up to 100 square centimeters on the face or balding scalp
Time to WorkReaction peaks around day 8. Skin usually settles within 2 to 3 weeks. Judge the result at about 8 weeks.
Evidence LevelGood. Approved on controlled trials against vehicle. It has not been compared head to head against 5-fluorouracil in a way that settles which clears more.
ImportantFace and balding scalp only. Not approved for the arms, hands, chest or legs.

How It Works

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Every cell that divides has to build an internal scaffolding of microtubules to pull its chromosomes apart. Tirbanibulin jams that scaffolding. A cell that cannot assemble it cannot complete division, and it dies instead.

The reason this is selective is speed. Sun-damaged cells in an actinic keratosis divide much faster than the normal skin around them, so they hit the blockade first and hardest. Normal skin, dividing slowly, mostly gets away with it. Tirbanibulin also interferes with Src kinase signaling, a growth pathway that is overactive in these lesions.

The practical difference from 5-fluorouracil is timing rather than kind. Both kill abnormal cells and both leave an inflammatory reaction behind. Tirbanibulin gets it done in five days of application, and the resulting reaction is generally shorter and less severe. It is the same story told faster.

What It Treats

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Moderate evidence
Trial evidence supports clearance of actinic keratoses on the face and scalp with a five-day course and less local reaction than older topicals. Long-term clearance data are shorter than for 5-FU, and it costs more.

Who It's For & Who It's Not

Who it's for

People with actinic keratoses on the face or balding scalp who want the shortest possible course.

People who could not face — or could not complete — weeks of twice-daily 5-fluorouracil.

People who need to be presentable soon and can spare roughly two to three weeks rather than one to two months.

People with a modest field of damage. The treated area is capped at about 100 square centimeters, roughly the size of a business card and a half.

Who it's not for

Anyone wanting to treat arms, hands, chest or legs. It is not approved there, and those areas were not what it was tested on.

Anyone with heavy, widespread field damage across a whole scalp and face. That usually needs 5-fluorouracil or photodynamic therapy.

Anyone with a thick, tender, growing or bleeding lesion — that gets a biopsy, not an ointment.

Anyone for whom cost is the deciding factor and generic 5-fluorouracil is an option. The price difference is large and it is not a small detail.

Children, and anyone who is pregnant or breastfeeding, where it has not been studied.

How to Take It

How to take it
  • One packet a day, five days in a row, then stop. That is the entire course. There is no week two.
  • Wash and dry the area first. Squeeze the packet onto a fingertip and spread a thin, even layer over the whole treatment field — not just the visible spots. As with all field treatments, the point is to reach the damage you cannot see yet.
  • Wash your hands immediately afterward with soap and water.
  • Do not wash or touch the treated area for about eight hours. Most people find applying it in the evening easiest, then washing it off in the morning.
  • Do not cover it with a dressing.
  • Keep it away from your eyes, the inside of your nose, your lips and your mouth. If it gets in your eye, rinse thoroughly with water — this drug can cause real eye irritation.
Missing a day
  • If you forget a day, apply it as soon as you remember and continue until you have had five applications. Do not double up.
What to expect afterward
  • Days 1 to 3often very little. Some people feel a mild sting.
  • Days 4 to 8redness, then flaking and crusting. This is normally the peak, and it lands a few days after you have already stopped applying it, which catches people out.
  • Weeks 2 to 3the crusting lifts and the redness fades. Most people look normal again by around the third week.
  • Week 8the point at which the result is judged. Smoother skin, flatter spots, and often some leftovers.

What to Avoid

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Your eyes
Tirbanibulin causes genuine eye irritation. Wash your hands right after applying, and be careful about rubbing your eyes overnight.
Washing the area for eight hours
after each application.
Sun
Treated skin burns easily. Hat, shade, and sunscreen once the skin can tolerate it.
Occlusive dressings
Other actives
Pause retinoids, acids and scrubs for the course and while healing.
Applying more than one packet a day, or extending the course
More is not better here — it just deepens the reaction. Five days means five days.
Peels, laser and waxing
until the skin has fully recovered.
Pregnancy and breastfeeding
It has not been studied; avoid it.

Side Effects

Common and expected
  • Local skin reaction in the treated field — redness, flaking, scaling and crusting. Expected, and it means it is working.
  • Application site pain, stinging or burning.
  • Itching.
  • Swelling, particularly on the forehead or eyelids when the forehead is treated.
  • Small blisters or pustules, and shallow erosions. Less common than with 5-fluorouracil, but they happen.
  • Eye irritation and watering, usually from transfer by hand.
  • Temporary lighter or darker patches during healing. On brown and Black skin, expect the reaction to look dusky or darker rather than bright red, and expect post-inflammatory hyperpigmentation to be the more likely aftermath — it fades, but it can take months, and sun protection during healing shortens it.
Tell your doctor
  • A reaction that is still worsening after about ten days, rather than settling.
  • Skin that is still raw or crusted a month after finishing.
  • Persistent eye pain, redness or blurred vision.
  • Any spot in the treated field that stays thick, tender or crusted once everything else has healed.
Stop and get care
  • Honey-colored crusting, pus, spreading warmth or worsening pain after the peak — that is likely a secondary infection.
  • Deep ulcers or open sores that will not crust over.
  • Swelling that closes an eye.
  • Fever or feeling unwell during the reaction.

How Long Until It Works

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The reaction happens fast — within a week — but the result takes about two months to assess.

Expect the treated skin to be visibly inflamed and flaking around day 8, back to roughly normal by the end of week two or three, and at its best at around week eight. That eight-week mark is when your dermatologist will want to look at what actually cleared.

Complete clearance of every lesion is not the usual outcome for any field treatment, and it is not the usual outcome here. Leftover spots get frozen off. If a large part of the field is unchanged at eight weeks, that is a signal to move to something stronger rather than to repeat the same five days.

What Happens When You Stop

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You stop after five days by design, and the reaction then builds for a few more days before it fades. Nothing is going wrong when that happens.

There is no rebound and no withdrawal. Once healed, the skin holds its improvement for as long as it holds it, usually a year or more.

Sun damage keeps accumulating, so new spots will appear over time and repeat treatment is normal. Retreating the same field with Klisyri is done, but the timing and whether to switch to a different treatment is a decision for your dermatologist rather than a refill request.

Who should not take it+

Do not use it if:

You are pregnant or breastfeeding

You are treating skin outside the approved area — arms, hands, chest, legs — unless your dermatologist has specifically decided to do so off-label

You have an undiagnosed thick, tender, growing or bleeding lesion

You are allergic to tirbanibulin

FAQ+
How much does it cost?This is the honest weak point. Klisyri is brand-only with no generic, and the list price for a five-day course runs into the hundreds of dollars in the US. Many insurance plans cover it, often after a prior authorization and usually after you have tried something cheaper first, and the manufacturer runs a copay program. Generic 5-fluorouracil, by comparison, is a few dollars a tube. If money is the constraint, that comparison is the whole conversation.
Is the reaction really milder than 5-FU?Generally yes, and it is much shorter. Most people get redness, flaking and crusting for a couple of weeks rather than a raw, weeping face for a month. It is not nothing — expect to look treated. But it is a different order of disruption.
Does it clear as well as 5-fluorouracil?Unclear, and worth saying plainly. Both are effective. They have not been compared head to head in a way that settles it. 5-FU is the older, more thoroughly used option for heavy field damage; Klisyri wins on speed and tolerability. Many dermatologists reach for Klisyri on a modest facial field and 5-FU when the damage is extensive.
Can I use it on my arms or hands?It is approved only for the face and balding scalp, and forearms and hands are the hardest areas for any topical to clear. Some dermatologists do use it off-label elsewhere. That is a decision to make with them, not on your own.
Why is the treatment area limited?The approved field is up to 100 square centimeters. The limit exists because that is what was tested and what the packet size supplies. If your damage covers more than that, you are probably a better candidate for 5-fluorouracil or photodynamic therapy.
Why did it get worse after I stopped?Because the reaction peaks around day 8, which is three days after your last application. That is the expected pattern, not a sign of a problem.
Can I go out in public during treatment?During the five days of application, usually yes — most people look fairly normal. The awkward stretch is roughly days 5 to 14, when redness and flaking peak. Plan around that rather than around the dosing days.
What if some spots are still there at eight weeks?Common. Leftovers are usually frozen off with cryotherapy, and anything thick or tender gets a biopsy.
Can I use makeup?Not on inflamed or crusted skin. Once it is only pink, mineral makeup is fine.
Does it prevent skin cancer?It treats the actinic keratoses that are there. Those spots are treated because a small number of them can progress to squamous cell carcinoma and there is no way to know which. Whether clearing a field today means fewer skin cancers years from now is debated, so it is fairer to think of Klisyri as clearing what is present than as insurance against the future. Sun protection and regular skin checks still do the long-term work.