Zest Health Guide to Topical Janus kinase (JAK) Inhibitors

What are Topical JAK Inhibitors and How do They Work?

Topical Janus kinase (JAK) inhibitors are a non-steroidal class of medication. They work by blocking JAK enzymes that send signals to your immune system to create inflammation. By "turning off" these signals, they can rapidly reduce itching, redness, and rash associated with immune-driven skin conditions.

Topical JAK Inhibitors: 

• Opzelura (ruxolitinib)— often used for atopic dermatitis (eczema) and nonsegmental vitiligo. Can reduce itch as early as 12 hours after the first use
• Anzupgo (delgocitinib)— specifically indicated for moderate to severe chronic hand eczema in adults

Getting Started: Using a Topical JAK Inhibitor Safely

Your Zest provider will choose the right treatment based on your diagnosis and the location of your symptoms. Here are a few key things to know before you start:

• Age Requirements: Opzelura is FDA-approved for patients 12 and older (vitiligo) or 2 and older (eczema). Anzupgo is for adults 18 and older
• Steroid-free: These medications do not cause skin thinning or stretch marks and can be used on sensitive areas, including the face and eyelids
• Active infections: Because JAK inhibitors affect the immune system, they should not be used if you have an active, serious infection. Talk to your provider if you’re unsure

Applying Topical JAK Inhibitors 

• Opzelura: Can be applied to affected areas on the body and face, including sensitive skin around the eyes, mouth, or groin. Do not use inside the eyes, mouth, or vagina
• Anzupgo: Applied specifically to affected areas on the hands and wrists

Application Tips:

• Frequency: Apply a thin layer twice daily
•  Limits: For Opzelura, do not use more than one 60g tube per week. For Anzupgo, do not exceed 30g per 2 weeks (60g per month).
• Hygiene: Wash your hands after applying — unless your hands are the area being treated.
• Consistency: Try pairing your application with a daily habit — like brushing your teeth — to help you stay consistent.

How Much Should I Use?

We recommend using the Fingertip Unit (FTU) when you are getting started:

• This is the amount of cream squeezed from the tip of your finger to the first crease.
• 1 FTU covers about the size of the front and back of one adult hand.

A few things to keep in mind as you get started:

• If you're treating a small spot, use less — you don't need a full FTU for every area
• For eczema, apply only to areas that need it, keeping total coverage to no more than 20% of your body surface area
• For vitiligo, limit coverage to 10% of your body surface area

Every person's skin is different, and different body parts need different amounts. Your Zest provider can walk you through exactly how much to use and where.

Getting Started

• Submit baseline photos of your skin condition for a severity assessment
• No routine blood work is needed, but please share all current and past medications with your provider
• Provide previous treatment records, if requested

Expected Results

• Itch Relief: Many patients feel a significant reduction in itching within days — sometimes even hours
• Clearing: For eczema, treatments are often used as needed until symptoms resolve
• Vitiligo: Repigmentation takes longer — often 6 or more months of consistent use to see meaningful results. Progress is real, even when it’s gradual

Is it Safe/Are There Any Side Effects?

Topical JAK inhibitors deliver medicine directly to the skin, which helps limit side effects. Most users experience only mild effects.

You may notice a black box warning on your packaging. Here’s what it means:

Oral (pill-form) JAK inhibitors have been linked to more serious risks in some patients. Because this topical medication stays on the skin, those risks are much lower — but the warning is included out of caution.

• Common effects: Acne or redness at the application site, mild cold symptoms, and headaches
• Rare serious risks: Although uncommon with topical use, there is a small risk of serious infections, blood clots, or blood count changes. Contact your provider immediately if you notice fever, leg swelling or pain, or shortness of breath
• Vaccinations: Make sure you’re up to date on vaccines (including shingles) before starting. Avoid live vaccines while using these medications

Storing Your Medication

• Store at room temperature
• Keep tube or bottle tightly closed
• Keep out of reach of children
• Do not ingest medication
• Check expiration date before each use

When to Contact Your Zest Team 

• No improvement after 8 weeks for eczema, or 24 weeks for vitiligo 
• Signs of a severe allergic reaction or infection
• Unusual worsening redness, pain, or swelling, or signs of skin infection (pus, warmth, fever)
• Fever, leg swelling, shortness of breath, or any other new or concerning symptom

Have more questions?

Contact your Zest care team by texting (865)-426-1746 or sending a chat message from your portal. You’ve got this, and we’ve got you. Together, let’s work toward relief and clear skin!