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JAK Inhibitors For Alopecia: Efficacy & Safety

Knox Beasley, MD

Reviewed by Knox Beasley, MD

Written by Rachel Sacks

Published 03/16/2023

Updated 05/08/2024

The first JAK inhibitor for alopecia has been approved by the FDA (U.S. Food and Drug Administration), and it looks like an effective option for treating certain types of hair loss, such as alopecia areata. If you have questions about JAK inhibitor alopecia and how it might fit into your hair loss prevention routine, we’ve got you covered.

Below, we’ll discuss JAK inhibitors, including how these new medications work for hair loss — from moderate to severe alopecia areata — and how they compare to conventional hair loss treatments like finasteride and minoxidil.

A JAK inhibitor (short for janus kinase inhibitor) is a relatively new treatment. It works through a complicated process that reduces the immune system’s ability to target certain areas of the body and cause autoimmune disease symptoms.

There are numerous JAK inhibitors on the market, some of which are used to treat patients with rheumatoid arthritis. These include tofacitinib (sold under the brand name Xeljanz®), baricitinib (the active ingredient in Olumiant®) and upadacitinib (Rinvoq®).

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Alopecia areata is an autoimmune disease. Sometimes called AA, it happens when the immune system targets, attacks and damages hair follicles, causing hair to shed.

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

But 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 hairs — a disease referred to as alopecia universalis or alopecia totalis.

Recently, baricitinib (Olumiant) was approved by the FDA for the treatment of AA in adults with severe alopecia areata. This particular JAK inhibitor alopecia is the first of its type approved to treat this form of hair loss not just on the scalp but throughout the entire body. It blocks 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.

Although baricitinib is currently the only JAK inhibitor approved by the FDA as a treatment for hair loss, other JAK inhibitors for alopecia have also been studied, such as ruxolitinib (Jakafi®).

A systematic review and meta-analysis found that JAK inhibitors had a good response rate. And while side effects were uncommon, typically mild and manageable, the researchers noted that case reports of adverse events varied across the studies they reviewed.

They concluded that JAK inhibitors are “efficacious and generally well-tolerated” as options for treating alopecia areata and achieving hair growth when used orally.

Oral tofacitinib and other oral JAK inhibitors like ritlecitinib (Pfizer’s Litfulo®, which blocks the subtype JAK3) may also help adolescents and pediatric patients dealing with not just alopecia areata but atopic dermatitis (eczema) and psoriasis too.

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Like other medications that get FDA approval, baricitinib went through a complex series of clinical trials and safety assessments to determine not just that it’s effective but also that it’s safe for people affected by alopecia areata to use on an ongoing basis.

JAK Inhibitor Side Effects

But as with any medication, JAK inhibition may cause side effects in addition to hair growth.

According to the FDA, the most frequently reported side effects of baricitinib 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, baricitinib shouldn’t be used with certain other medications, including other JAK inhibitors, biologic immunomodulators or 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.

Most of the time, hair loss in men can be treated using hair regrowth medications like finasteride and minoxidil.

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, it’s usually recommended that minoxidil is used in conjunction with other treatments.

Put simply, 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 simply aren’t the best remedies for alopecia areata.

Hair loss treatments, delivered

If you’re affected by alopecia areata, using a JAK inhibitor such as baricitinib may help you avoid developing patchy hair loss and regrow hair you’ve lost as a result of your immune system attacking your hair follicles.

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.

As such, 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 such as 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.

10 Sources

  1. Ho, C.H., Sood, T. & Zito, P.M. (2022, October 16). Androgenetic Alopecia. StatPearls. Retrieved from
  2. Alopecia Areata. (2021, April). Retrieved from
  3. Lin, C. M., Cooles, F. A., & Isaacs, J. D. (2020). Basic Mechanisms of JAK Inhibition. Mediterranean journal of rheumatology, 31(Suppl 1), 100–104. doi: 10.31138/mjr.31.1.100. Retrieved from
  4. Zito, P.M., Bistas, K.G. & Syed, K. (2022, August 25). Finasteride. StatPearls. Retrieved from
  5. Badri, T., Nessel, T.A. & Kumar, D.D. (2021, December 19). Minoxidil. StatPearls. Retrieved from
  6. Fiedler-Weiss, V.C. (1987). Topical minoxidil solution (1% and 5%) in the treatment of alopecia areata. Journal of the American Academy of Dermatology. 16 (3 Pt 2), 745-748. Retrieved from
  7. Shawky, A.M., et al. (2022, May). A Comprehensive Overview of Globally Approved JAK Inhibitors. Pharmaceutics. 14 (5), 1001. Retrieved from
  8. FDA Approves First Systemic Treatment for Alopecia Areata. (2022, June 13). Retrieved from
  9. King, B., et al. (2022, May). Two Phase 3 Trials of Baricitinib for Alopecia Areata. The New England Journal of Medicine. 386 (18), 1687-1699. Retrieved from
  10. Yan, D., et al. (2022). The efficacy and safety of JAK inhibitors for alopecia areata: A systematic review and meta-analysis of prospective studies. Frontiers in Pharmacology. 13, 950450. Retrieved from
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Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Knox Beasley, MD

Dr. Knox Beasley is a board certified dermatologist specializing in hair loss. He completed his undergraduate studies at the United States Military Academy at West Point, NY, and subsequently attended medical school at Tulane University School of Medicine in New Orleans, LA. 

Dr. Beasley first began doing telemedicine during his dermatology residency in 2013 with the military, helping to diagnose dermatologic conditions in soldiers all over the world. 

Dr. Beasley is board certified by the American Board of Dermatology, and is a Fellow of the American Academy of Dermatology.

Originally from Nashville, TN, Dr. Beasley currently lives in North Carolina and enjoys spending time outdoors (with sunscreen of course) with his wife and two children in his spare time. 





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