Here's Why So Many People Are Talking About 'Paxlovid Mouth'

Here's Why So Many People Are Talking About 'Paxlovid Mouth'
  • Paxlovid, the antiviral drug designed to prevent hospitalization and death stemming from COVID-19 illness, is often prescribed to those impacted by a SARS-CoV-2 infection.

  • The highly effective drug has a list of 7 total potential side effects, including an altered sense of taste, which social media users are dubbing "Paxlovid Mouth."

  • While side effects are temporary, healthcare experts say there are a handful of pre-existing conditions and medical histories that may make this antiviral drug harmful to your health.

  • Below, you'll learn: What is Paxlovid, and how it treats COVID-19; a full list of potential side effects associated with Paxlovid; what is "Paxlovid Mouth" and why the bitter, acrid taste may be occurring; and if Paxlovid is safe to take.


Paxlovid is an antiviral drug treatment that's highly effective at helping those at high risk of death or severe COVID-19 complications recover without heading to the hospital. Some doctors may call the product "lifesaving," and for good reason — recent Food and Drug Administration (FDA) figures indicated Paxlovid works to prevent about 90% of COVID-19 hospitalizations among unvaccinated individuals, those over the age of 65, and immunocompromised people. And while many healthcare providers have been prescribing the antiviral treatment — which consists of two individual drugs, nirmatrelvir and ritonavir — during Omicron-fueled outbreaks, quickly recovering Americans are discovering that the pill isn't without its own minor faults.

There's been a flurry of chatter on social media platforms about some of Paxlovid's potential side effects for recovering individuals, namely centered on what's now known colloquially as "paxlovid mouth."

"Wow my doctor was not joking about the gross taste in your mouth while taking Paxlovid," one user recently shared on Twitter. "The Paxlovid pills are flavorless, but they make my mouth taste like metal and bile, all the time. It's really delightful," another quipped. Someone else noted: "It has been only hours since my 1st dose of Paxlovid, but it's doing something. Strong weird metallic grapefruit taste in mouth, but tightness in my chest is GONE and I can take a full deep breath. Heart rate, which had remained up at 86 after my walk, dropped to 64."

The drug's manufacturer, Pfizer, currently is distributing its effective COVID-19 treatment under an Emergency Use Authorization from FDA officials; researchers are still learning more about Paxlovid this year, including a potential symptom rebound for some individuals. But healthcare providers have already been informed about seven distinct potential side effects that come with the antiviral pill, and patients are learning more about them currently.

Read on to learn about Paxlovid's potential side effects, including an altered sense of taste that's been referred to as "Paxlovid Mouth."

What is Paxlovid and how does it treat COVID-19 symptoms?

There's a good chance you'll hear your primary healthcare provider talk about Paxlovid, an antiviral medication for individuals over the age of 12 that is designed to reduce the risk of severe COVID-19 disease. The treatment combines two individual drugs (packaged as two different colored pills!) and is often prescribed for a period of five days shortly after a confirmed COVID-19 diagnosis. "One [pill] kills the virus and the other boosts the activity of the first," explains Shira Doron, M.D., an infectious disease physician and epidemiologist at Boston's Tufts Medical Center.

More specifically, the second pill — a low dose of ritonavir — helps to slow the individual's metabolism so that the first pill can effectively work better over the course of treatment, says Kit Longely, a Pfizer Global Media Relations spokesperson. "[It] helps slow the metabolism, or breakdown, of nirmatrelvir in order for it to remain active in the body for longer periods of time, at higher concentrations, to help combat the virus," he adds.

Dr. Doron clarifies that the earliest studies conducted on Paxlovid weren't conducted solely on Paxlovid's ability to reduce symptoms, but Longley tells Good Housekeeping that "robust efficacy" was recorded in patients who began taking Paxlovid within five days of exhibiting COVID-19 symptoms.

Generally, it's understood that Paxlovid may help to shorten the length of a sickness, and in any case, help to keep individuals' symptoms from progressing into dangerous territory.

Prescriptions for Paxlovid are becoming increasingly common for anyone experiencing a COVID-19 illness and exhibiting symptoms. Current recommendations indicate that anyone with even a single risk factor for COVID-19 complications, or anyone exhibiting symptoms in any severity, can take Paxlovid. Sick individuals don't need to see their doctor in person to receive a prescription, either, as Dr. Doron adds telehealth visits are sufficient enough to receive this antiviral treatment sooner rather than later.

What are Paxlovid's possible side effects?

While there's been a stir on social media platforms and online community boards about Paxlovid's tendency to trigger a prolonged bitter taste, this temporary side effect isn't what healthcare providers are most concerned about.

"The most serious side effect is Paxlovid's drug-drug interaction, and it's very important to tell the prescriber about every prescription and over-the-counter medication and supplement you are taking," Dr. Doron stresses. The latest FDA fact sheet about Paxlovid indicates that there are 14 different medications that, taken concurrently, would cause serious risk to your health and your liver, specifically. Some of the listed medications may prompt your care provider to consider other options altogether — the National Institutes of Health (NIH) have published a comprehensive list of medications that are expected to have drug-on-drug interactions with the individual aspects of Paxlovid.

Officially, there are seven potential Paxlovid side effects listed by the FDA that your care provider should make you aware of:

  • Liver problems

  • Allergic reactions

  • Muscle aches or pains

  • High blood pressure

  • Altered sense of taste

  • Diarrhea, nausea, and other gastrointestinal distress

  • Resistance to HIV medicines

All of these side effects are temporary in nature, and patients may experience a unique combination of one, two or more, at any time during their Paxlovid treatment. The same Pfizer spokesperson indicated that early research on nirmatrelvir published in the New England Journal of Medicine suggested that side effects recorded were similar in both placebo and active treatment groups, which may indicate that some of these side effects are simply tied to active SARS-CoV-2 infections.

While unexplored by federal health agencies, there is also mounting concern vocalized by healthcare providers over a potential rebound effect linked to Paxlovid in vaccinated individuals. According to a medical preprint shared in late April, researchers in Boston identified a 71-year-old vaccinated man who experienced a breakthrough infection and was prescribed Paxlovid shortly after his diagnosis; within 48 hours, the patient reported being symptom-free, and remained so for over a week. His symptoms returned on Day 9, however, and he remained feeling sick for four additional days.

Genetic sequencing highlighted in the preprint indicated that his initial infection had returned. But as this is one of the first pieces of documented data on this phenomenon, health officials don't have enough info to say if this rebound effect is widespread just yet.

What is "Paxlovid Mouth"? Understanding the bitter taste in your mouth:

According to Dr. Doron, the bitter, almost rancid taste individuals are experiencing after taking Paxlovid has become the most common side effect she's seen in her patients. "There are several theories, but no one knows why exactly Paxlovid causes this side effect," she explains. "It has been seen with other medications."

What is known, according to Longley and noted in other Pfizer research, is that both nirmatrelivr and ritonavir are naturally bitter — which likely is why Paxlovid is leading to a sustained bitter mouthfeel throughout treatment. Officially labeled dysgeusia within the scientific community, the altered sense of taste was noted in one of Pfizer's clinical trials; about 6% of participants in the active treatment group experienced the altered taste, compared to just .3% of those in a placebo group, Longley tells us.

Unfortunately, healthcare providers haven't found a way to entirely prevent all individuals who are prescribed Paxlovid from experiencing a bitter mouthfeel during their treatment — nor have they indicated if there's a solution to stop the bad taste after you've noticed it.

If you're currently experiencing a bitter, foul taste in your mouth while taking the drug, know that it's entirely normal, and it will pass. "This is to be expected — I'm not sure how long it should last for most," Dr. Doron adds. "This is all still pretty new."

Given that there is still active research being conducted on Paxlovid and other antiviral medications, developers may discover the means to effectively block this temporary nuisance entirely in future iterations of the treatment.

Is Paxlovid safe to take?

Since Paxlovid can be prescribed in a virtual diagnosis, it's crucial to disclose any existing prescriptions you may be taking to avoid potentially serious risks to your health — and note existing allergies as well. Because your primary healthcare provider knows your medical history at length, speaking with them directly about adding Paxlovid or any other antiviral oral medication into your COVID-19 recovery is highly recommended.

In addition to other federal health agencies, the World Health Organization (WHO) has officially recommended Paxlovid for "mild and moderate COVID-19 patients at highest risk of hospital admission." While the drug's noted side effects can be discouraging, medical experts have established that all are temporary and limited to the drug's scheduled treatment cycle — meaning 'Paxlovid Mouth' isn't something that'll impact you forever.

It's clear that the benefits of this effective drug outweigh these temporary side effects for most individuals facing a COVID-19 diagnosis. "Given the mostly mild nature of [each] event and the fact that very few participants discontinued the study as a result, adverse reaction[s] do not meet criteria for inclusion as a warning from regulators," Longley explains.

Don't be discouraged if your primary healthcare provider doesn't immediately prescribe Paxlovid once you've tested positive for COVID-19; while it's safe for a majority of the population, there's a chance that a pre-existing medical condition or prescription puts you at risk with Paxlovid. Plus, those who aren't experiencing symptoms currently and aren't considered at high-risk for severe complications are being discouraged by WHO officials from taking Paxlovid, as its "benefits were found to be negligible," according to the group.

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