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Pfizer Alopecia Treatment: What Is Ritlecitinib & How Does It Work?
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on May 10, 2023

Pfizer is the world’s biggest research-based pharmaceutical company. They’re responsible for some of the most successful medications in circulation — including the first UK-approved Covid-19 vaccine. Recently, Pfizer filed for approval from the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for its alopecia medication, ritlecitinib.

But Pfizer’s alopecia drug also hit the headlines in 2022 for an entirely different reason. Pfizer sponsored the 2022 Oscars, leading conspiracy theorists to claim that the now-infamous Will Smith/Chris Rock incident was a staged publicity stunt to promote Pfizer’s alopecia medication. Rock’s joke, after all, made light of Jada Pinkett-Smith’s hair loss condition.

will smith slaps chris rock at oscars 2022 - pfizer alopecia conspiracy theory jada pinkett smith alopecia oscars 2022

This theory isn’t true [1]. So what do we know about ritlecitinib? In this article, you’ll find out:

  • what ritlecitinib is and how it works
  • the effectiveness of ritlecitinib
  • when ritlecitinib will be available.

What is ritlecitinib, Pfizer’s alopecia drug?

Ritlecitinib is a drug designed to help stimulate hair growth in people who have alopecia areata and other autoimmune hair loss conditions. Back in 2018, this Pfizer alopecia drug was given Breakthrough Therapy status by the FDA, thanks to its significance as a potential treatment for alopecia.

Ritlecitinib is a Janus kinase (JAK) inhibitor that’s taken once a day as an oral tablet. JAK inhibitors block immune response signals, essentially suppressing the immune system to avoid an unnecessary autoimmune response.

An autoimmune response happens when the body overreacts to a trigger, attacking its own cells. Alopecia areata is an autoimmune condition in which white blood cells attack the hair follicles. Alopecia totalis and alopecia universalis are related conditions that involve hair loss across the whole head and the entire body respectively.

Ritlecitinib blocks signals from molecules and immune cells that are linked with alopecia areata symptoms [2]. It’s a highly selective JAK inhibitor, which means it can target more specific enzymes than other drugs in this category. Researchers suggest this may lead to fewer side effects than other JAK inhibitors, making it a highly anticipated treatment [2].

Pfizer alopecia medication trial results

Recent clinical trials show significant improvements in hair loss for alopecia patients taking ritlecitinib [3]. The latest trial examined results in 719 people who each had at least 50% hair loss as a result of alopecia areata, alopecia totalis, or alopecia universalis.

After 6 months of taking ritlecitinib, a statistically significant proportion of patients had regrown hair to at least 80% scalp coverage, compared with just a handful of patients taking the placebo.

Combined with promising results from earlier trials, these positive results mean that Pfizer’s alopecia drug may soon be available as a new treatment for alopecia areata.

Side effects of ritlecitinib

Like all medicines, ritlecitinib has several known side effects. An earlier study found that two-thirds of ritlecitinib trial patients experienced at least one adverse effect, although the majority were mild [4].

Side effects of ritlecitinib include:

  • Headaches
  • Cold (nasopharyngitis)
  • Upper respiratory tract infection
  • Acne
  • Nausea
  • Shingles

There was also one case of pulmonary embolism, and 2 patients developed breast cancer during the trial, although it’s unclear if this was linked with the alopecia drug.

Other JAK inhibitors are known to be linked with cancer and heart problems. The FDA has previously issued a warning to medication users to highlight these potentially serious side effects [5].

Is ritlecitinib available now?

Ritlecitinib isn’t available for purchase or prescription just yet. In September 2022, Pfizer filed for approval from the FDA and EMA to treat alopecia areata in those aged 12 and over. A decision is expected in spring 2023 from the FDA (in the US) and winter 2023 from the EMA (in Europe).

Pfizer then aims to make ritlecitinib available to the public by 2025.

What does this mean for alopecia patients?

There are currently very few approved treatments for autoimmune-related hair loss conditions like alopecia areata. Hair transplants for alopecia areata aren’t usually recommended, either. So it’s great news that pharmaceutical companies are actively researching and trialling new treatments for these conditions.

In 2022, the FDA also approved Olumiant, the first systemic treatment for alopecia areata. So this is clearly a priority for pharmaceutical organisations at the moment. New treatments are being discovered, tested, and approved to give alopecia patients more treatment options in future.

How to tackle alopecia areata

If you’re currently experiencing alopecia areata — or another type of unexplained hair loss — it’s important to seek help from a professional trichologist. They can carry out hair loss blood tests and other hair and scalp examinations to determine the root cause of your condition. They can then find the right treatment for you based on your diagnosis.

Book a free consultation at the Wimpole Clinic to help diagnose and address your hair loss today.

Pfizer Alopecia Treatment: What Is Ritlecitinib & How Does It Work?, Wimpole Clinic


  1. PolitiFact Fact Check | Pfizer Alopecia Drug Oscars 2022
  2. Evaluating the Therapeutic Potential of Ritlecitinib for the Treatment of Alopecia Areata
  3. PF-06651600 for the Treatment of Alopecia Areata (ALLEGRO-2b/3)
  4. A phase 2a randomized, placebo-controlled study to evaluate the efficacy and safety of the oral Janus kinase inhibitors ritlecitinib and brepocitinib in alopecia areata: 24-week results
  5. FDA requires warnings about increased risk of serious heart-related events, cancer, blood clots, and death for JAK inhibitors that treat certain chronic inflammatory conditions
Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on May 10, 2023
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on May 10, 2023

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