JAK Inhibitors For Alopecia: Efficacy & Safety

In 2022, the U.S. Food and Drug Administration (FDA) approved the first JAK inhibitor for alopecia. Could a JAK inhibitor be the right hair loss treatment option for you?

Short answer: It depends on the type of hair loss you’re experiencing.

Below, we discuss JAK inhibitors, how they target certain forms of hair loss, how they compare to conventional hair loss treatments like finasteride and minoxidil, and more.

A JAK inhibitor (short for janus kinase inhibitor) is a relatively new treatment. This type of medication works by calming an overactive immune system, helping to limit symptoms of autoimmune diseases.

Several JAK inhibitors are available to treat rheumatoid arthritis, including

• Tofacitinib (Xeljanz®)

• Baricitinib (Olumiant®)

• Upadacitinib (Rinvoq®)

Alopecia areata (AA) is an autoimmune disease where the immune system targets, attacks, and damages hair follicles, causing hair to shed.

Unlike male pattern baldness (androgenetic alopecia) — which can be measured using the Norwood scale — alopecia areata generally causes hair to fall out in small patches about the size of a quarter.

Alopecia areata can vary in severity. While many will experience small patches of hair loss limited to the scalp, others might face complete loss of facial and body hair known as alopecia universalis or alopecia totalis.

Baricitinib (Olumiant) has FDA approval to treat AA in adults with severe alopecia areata.

It’s the first FDA-approved JAK inhibitor for AA-related hair loss on the scalp and body. It works by blocking the janus kinase subtypes JAK1 and JAK2.

In a series of randomized, double-blind, placebo-controlled trials, people with alopecia areata experienced improvements in hair regrowth with baricitinib compared to a placebo.

The research also found that 4 milligrams (mg) of baricitinib — the highest dose used in the studies — led to more improvement in human hair follicle regrowth than the lower 2-milligram dose.

Baricitinib is currently the only JAK inhibitor approved by the FDA as a treatment for hair loss. But researchers have also studied other JAK inhibitors for alopecia, including ruxolitinib (Jakafi®).

A systematic review and meta-analysis found that oral JAK inhibitors generally deliver effective results. And while side effects were uncommon, typically mild, and manageable, adverse events did occur.

Oral tofacitinib and other oral JAK inhibitors like ritlecitinib (Pfizer’s Litfulo®, which blocks the subtype JAK3) may also help teens and kids dealing with alopecia areata and skin conditions like atopic dermatitis (eczema) and psoriasis.

Like other medications that get FDA approval, baricitinib went through a complex series of clinical trials and safety assessments to determine that it’s effective and safe for ongoing use in people with alopecia areata.

JAK Inhibitor Side Effects

But as with any medication, JAK inhibition may cause side effects.

The most common side effects include:

• Headaches

• Skin issues, such as acne

• Upper respiratory tract infections

• Lower respiratory tract infections

• Elevated liver enzyme levels

• Urinary tract infections (UTIs)

• Inflamed hair follicles (folliculitis)

• Anemia (low red blood cells)

• Low white blood cell count

• High cholesterol levels

• Genital yeast infections

• Shingles (herpes zoster)

• Abdominal pain

• Weight gain

• Fatigue

Additionally, you shouldn’t take baricitinib with the following medications:

• Other JAK inhibitors

• Biologic immunomodulators

• Medications that suppress the immune system

It’s also important to note that JAK inhibitors have several black box warnings, the strongest type of warning from the FDA. So be sure to read the fine print before taking them and talk to your healthcare provider about any safety concerns.

If you have alopecia areata, your provider will go over potential side effects, drug interactions, and long-term safety before prescribing any type of JAK inhibitor. Together, you can weigh the possible risks and benefits of this medication for your particular situation.

For more insight, see our blog on what to avoid when you have alopecia areata.

Medications like finasteride and minoxidil are proven hair loss treatments.

Finasteride works by limiting dihydrotestosterone (DHT), a hormone that can cause hair follicles to miniaturize and shed. But since alopecia areata isn’t triggered by DHT, medications like finasteride aren’t effective at stopping this form of hair loss.

Available as a topical foam or liquid solution, minoxidil works by improving blood flow to your scalp to encourage scalp hair regrowth in men with receding hairlines, bald spots, or central scalp hair loss. One clinical study found that the medication produced noticeable regrowth of hair in patients with alopecia areata.

However, if you have alopecia areata, you’ll get the best results by combining minoxidil with other treatments.

Conventional hair loss treatment options — the kinds you might use if you notice a receding hairline or mild thinning — work well for male pattern baldness, but they aren’t the best remedies for alopecia areata.

If you have alopecia areata, using a JAK inhibitor such as baricitinib may help you avoid patchy hair loss and regrow hair you’ve lost as a result of the autoimmune condition.

JAK inhibitors are fairly new medications for hair loss. You may need to talk to a healthcare provider who specializes in the treatment of alopecia areata to access this type of medication.

You can ask your primary care provider for a dermatology referral, or schedule an appointment with a medical professional in your area who specializes in treating autoimmune hair loss.

There are a few things to keep in mind if you’re considering this type of medication for hair loss:

• Not everyone experiences improvements with JAK inhibition. Research suggests that nearly two in every five people experience significant hair regrowth with Olumiant. In other words, it works in some cases, but not for everyone.

• JAK inhibitors aren’t proven to treat male pattern baldness. This type of medication is only approved for severe alopecia areata, not the male pattern hair loss that can cause a receding hairline.

If you’re starting to develop a receding hairline, a bald patch at your crown, or other early signs of balding, you’ll get better results from treatments like finasteride and minoxidil.

We offer these medications as part of our range of hair loss treatments for men, following an online consultation with a healthcare provider who can determine if a prescription is appropriate.

Interested in learning more before you get started? Our guide to the best treatments for thinning hair covers how to limit shedding and maintain your hair as you get older, from medications to healthy habits and more.