SARS-CoV-2 disrupts taste through a combination of direct viral invasion of taste bud cells, inflammatory damage, and changes to saliva, all of which can leave food tasting metallic, bitter, or simply wrong. Roughly a third of COVID-19 patients experience some form of taste dysfunction, and while the problem overlaps with the more widely discussed loss of smell, research has confirmed that COVID genuinely damages the taste system on its own. The biology behind this turns out to be surprisingly layered, and the story does not end when the infection clears.
The Virus Gets Directly Into Your Taste Cells
To infect a cell, SARS-CoV-2 needs to latch onto a protein called ACE2 on the cell’s surface, with help from another protein called TMPRSS2. Both of these proteins are found in abundance on cells lining the mouth, including the taste buds of the tongue and the tissue of the salivary glands.1PubMed Central. SARS-CoV-2 Infection and Taste Alteration: An Overview Researchers examining tongue tissue found that ACE2 and TMPRSS2 were strongly present in the layers of the tongue’s papillae and in taste buds themselves, giving the virus a direct route of entry.2PubMed. ACE2 and TMPRSS2 immunolocalization and oral manifestations of COVID-19
Animal studies have added visual proof. In a hamster model of COVID-19, viral particles were found inside the taste buds of the tongue’s large papillae, persisting there for weeks after infection.3PubMed Central. Histopathology of the tongue in a hamster model of COVID-19 The virus was also detected in the serous and mucous salivary glands at the back of the tongue for up to six weeks. And in a human case, researchers confirmed replicating virus inside the taste buds of a COVID-19 patient who was experiencing taste changes, along with disrupted stem cell layers that had not fully recovered even six weeks after symptoms started.4PubMed Central. Human Taste Cells Express ACE2: a Portal for SARS-CoV-2 Infection
Inflammation Does Its Own Damage
Beyond the direct infection, COVID-19 triggers an intense immune response that creates collateral harm. The flood of inflammatory signaling molecules that the body releases to fight the virus can itself injure taste receptor cells. Specifically, inflammatory cytokines can trigger cell death in taste buds and interfere with the normal renewal process that keeps them functioning.5PubMed. The Pathogenesis of COVID-19-Related Taste Disorder and Treatments Taste cells are unusually vulnerable to this because they turn over rapidly, being replaced every one to two weeks under normal conditions. If the inflammation disrupts that cycle, the supply of fresh taste cells slows or stalls.
Lab experiments have made this concrete. When researchers exposed rat taste buds to the SARS-CoV-2 spike protein alone, without a full infection, the tissue showed elevated levels of the inflammatory molecule TNF-α and increased cell death within taste buds.6PubMed Central. SARS-CoV-2 recombinant spike protein induces cell apoptosis in rat taste buds That finding suggests the spike protein itself can provoke damage, even before the immune system mounts a full-blown response. Separately, organoid experiments using lab-grown taste tissue showed that the inflammatory cytokines interferon-γ and TNF impaired taste cell generation, either by killing developing cells or by blocking their maturation.7Monell Chemical Senses Center. Mechanisms of Long-term Taste Loss in Post-Acute Sequelae of COVID-19
Changes in Saliva Play a Role Too
Saliva is not just background moisture in your mouth; it is actively involved in how you taste food. It dissolves flavor molecules and carries them to taste receptors, and its composition, including pH, enzymes, and mineral content, influences how those receptors respond. When COVID-19 infects salivary gland cells, it can alter the makeup and volume of saliva in ways that distort taste perception.8PubMed Central. Association of Salivary Content Alteration and Early Ageusia Symptoms in COVID-19 Infections: A Systematic Review
Researchers found SARS-CoV-2 genetic material in the ducts and secretory cells of the salivary glands, along with signs of chronic inflammation. Dry mouth was one of the most common follow-on symptoms, and that reduced salivary flow can independently impair taste.9Japanese Dental Science Review. Pathogenesis of taste impairment and salivary dysfunction in COVID-19 patients In one clinical comparison of post-COVID patients and healthy controls, dry mouth was reported by about 18% of the post-COVID group and by none of the controls.10Scientific Reports. Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions
What “Tasting Bad” Actually Feels Like
COVID-related taste disturbance is not just about food becoming bland. For many people, flavors become actively unpleasant. The clinical term is dysgeusia, and the specific distortions vary. In one study comparing post-COVID patients with healthy controls, about a third of the post-COVID group reported dysgeusia, and among those people, more than half described a metallic taste, about a fifth reported a persistent bitter taste, and the remainder described flavors as rotten or harsh.10Scientific Reports. Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions These are not subtle shifts. People describe once-loved foods tasting like chemicals, and the distortion can persist for months.
The type of taste quality affected also matters. A study of long-COVID patients who underwent detailed taste testing found that loss of sweet, umami, and bitter perception was significantly more common than loss of salty or sour perception. These three qualities all depend on a shared signaling molecule in taste cells, suggesting the virus or the resulting inflammation targets a specific molecular pathway rather than wiping out taste indiscriminately.11PubMed. Taste dysfunction in long COVID
Is It Really Taste, or Is It Smell in Disguise?
This question plagued researchers from the start. Most of what people experience as “taste” during a meal is actually flavor, which depends heavily on the sense of smell. When your nose is blocked during a cold, food tastes flat, but your tongue’s ability to detect sweet, salty, sour, and bitter is technically intact. So when COVID patients reported losing their taste, skeptics wondered whether they were really just losing their smell and misidentifying the problem.
The evidence now leans strongly toward COVID causing genuine taste loss, independent of smell. A large-scale study involving nearly 11,000 participants used at-home taste tests with basic stimuli like sugar and salt, which engage the tongue directly without any olfactory component. Participants with COVID showed reduced perceived intensity for these pure taste stimuli, confirming the dysfunction was not simply a smell-taste confusion.12PubMed Central. Covid-19 affects taste independently of smell: results from a combined chemosensory home test and online survey from a global cohort (N=10,953) A meta-analysis pooling data from hundreds of studies and over 138,000 COVID-positive patients found that roughly 37% reported taste dysfunction, and importantly, studies using direct taste measurement found rates at least as high as self-report studies, not lower as you would expect if most reports were just smell confusion.13PubMed Central. Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis
That said, a notable gap exists between what patients report and what blinded testing reveals. One review found that while self-reports of taste loss were very common, validated psychophysical testing showed dysfunction in up to about a quarter of patients, much lower than the self-report numbers.14PubMed Central. The taste of the pandemic-contemporary review on the current state of research on gustation in coronavirus disease 2019 (COVID-19) Part of this discrepancy is likely that many people genuinely cannot tell the difference between losing their ability to taste and losing the retronasal smell that makes food flavorful. Both are real problems, but they have different underlying causes.
The Brain’s Taste Regions Show Changes Too
The damage is not confined to the mouth. Brain imaging studies have found measurable changes in regions responsible for processing taste. Using diffusion-weighted MRI, researchers found that COVID-19 patients during the acute phase of illness had increased water diffusion in taste-related brain areas, including the insular cortex and the frontal operculum, compared to pre-pandemic baseline values. These changes indicate microstructural disruption, essentially swelling or tissue damage, in the brain regions where taste signals are interpreted.15PubMed Central. Neurological Impact of SARS-CoV-2 Changing Variants: A 4-Year DW-MRI Study on Olfactory and Taste-Related Brain Regions
Some researchers have also proposed that the virus disrupts signaling molecules called semaphorins, which guide the nerve fibers that carry taste information from the tongue to the brain. If those guidance pathways are disturbed, the connection between a taste cell detecting something and your brain correctly interpreting what that something is could break down, potentially explaining why food does not just taste weaker but actively wrong.
Why Omicron Spared More People’s Taste
If you caught COVID in 2022 or later, you may have noticed that taste and smell problems were less of a feature. That is not anecdotal. Contact-tracing data from England comparing Omicron and Delta infections found that loss of smell or taste was far less common with Omicron, with roughly a quarter of the odds of the same symptom during Delta infections.16PubMed Central. Comparative symptomatology of infection with SARS-CoV-2 variants Omicron (B.1.1.529) and Delta (B.1.617.2) from routine contact tracing data in England The reasons are still being worked out, but one leading explanation is that Omicron shifted toward infecting the upper airways via a different cellular entry route, reducing its penetration into the tissues where taste and smell receptors sit. Widespread immunity from vaccination and prior infection likely also played a role in reducing the severity of all symptoms, including chemosensory ones.
Genetics Influence Who Loses Their Taste
Not everyone who catches COVID experiences taste problems, and genetics help explain why. A genome-wide association study of nearly 70,000 people identified a region near the UGT2A1 and UGT2A2 genes as significantly associated with COVID-related loss of smell or taste. Both genes are active in the olfactory lining and are involved in metabolizing odorant molecules.17PubMed. The UGT2A1/UGT2A2 locus is associated with COVID-19-related loss of smell or taste People carrying certain variants at this locus had a higher risk of chemosensory loss, providing the first concrete genetic link to the phenomenon. Sex also appears to matter for recovery. A meta-analysis found that women were less likely to regain their sense of taste compared to men, though the reasons for that disparity remain unclear.18BMJ. Prognosis and persistence of smell and taste dysfunction in patients with covid-19: meta-analysis with parametric cure modelling of recovery curves
How COVID Compares to Other Respiratory Viruses
Plenty of viruses can dull taste, from the common cold to influenza, so it is fair to ask whether COVID is really different. The data say yes, dramatically so. A matched comparison of COVID-19 and influenza patients found that the three-month incidence of smell and taste disorders was about 11 times higher after COVID than after influenza.19PubMed. Comparison of the incidence of smell and taste disorders between influenza and COVID-19 Researchers have also suggested that the mechanisms differ. While a standard cold tends to affect chemosensory function mainly through nasal congestion blocking odor molecules, COVID appears to involve direct damage to sensory cells and possibly central nervous system involvement, creating a distinct pattern of dysfunction.20Rhinology. Comparison of COVID-19 and common cold chemosensory dysfunction
Recovery and the Long-Tail Problem
The good news is that taste recovers in most people. A large meta-analysis estimated that about 79% of patients had recovered their sense of taste by 30 days, and roughly 98% by six months.18BMJ. Prognosis and persistence of smell and taste dysfunction in patients with covid-19: meta-analysis with parametric cure modelling of recovery curves Those are encouraging numbers, but they leave a small fraction, estimated around 4-5%, with persistent taste problems that may become permanent. For perspective, even that modest percentage translates to millions of people worldwide given the scale of the pandemic.
A reassuring finding comes from a large study that formally tested taste function using a validated instrument (the Whole-mouth Equivalence Taste Test) in people with a history of COVID and found no significant difference in overall taste scores compared to people who had never had COVID. Scores fell within normal ranges regardless of which variant had caused the infection.21JAMA Network Open. Long-Term Taste and Smell Outcomes After COVID-19 This suggests that for the vast majority, taste function objectively normalizes even if the subjective experience of recovery feels slow or incomplete.
For the smaller group with lasting dysfunction, the picture is more nuanced. A biopsy study of long-COVID patients reporting persistent taste trouble found that while overall taste bud structure and nerve supply were largely preserved, specific types of taste receptor cells were depleted, particularly those responsible for sweet, umami, and bitter detection. The study found occasional disorganized taste buds and abnormal isolated cells in the surrounding tissue, but not the wholesale destruction you might expect.11PubMed. Taste dysfunction in long COVID The problem seems to be targeted, not total.
What You Can Do About It
There is no single proven cure for COVID-related taste loss, but a few approaches have shown promise. The most studied is olfactory training, which involves repeatedly sniffing a set of strong, distinct scents (classically rose, lemon, clove, and eucalyptus) for several months. Because smell and taste are intertwined, improving smell function can indirectly help with the flavor experience of food. Studies have found significant improvements in olfactory scores after a course of training.22PubMed Central. Olfactory training with essential oils for patients with post-COVID-19 smell dysfunction: A case series 23Mucosa. Management of post-COVID olfactory disorder: Is olfactory training effective on recovery of olfactory mucosal function?
A small trial tested oral zinc supplements combined with steroids in long-COVID patients with persistent chemosensory loss. Smell scores improved significantly after two to four months of treatment, though the taste results were less encouraging: among the few patients with objectively measured taste loss, none showed improvement on standardized taste testing, even though overall group taste scores did rise modestly.24PubMed Central. Effect of oral zinc and steroids on long COVID hyposmia and hypogeusia The results underscore how stubborn true taste dysfunction can be compared to smell dysfunction, even with active treatment.
On a practical level, many people with ongoing dysgeusia find that leaning on textures and temperature extremes, like crunchy, cold, or spicy foods, helps make eating more satisfying when flavor itself is unreliable. Others adjust seasoning with vinegar, citrus, or chili rather than piling on salt and sugar, which can bring its own health problems over time.
The Hidden Toll on Eating and Mood
Taste dysfunction affects far more than meals. Research on long-COVID patients found that when food became bland or actively disgusting, people’s entire relationship with eating shifted. Some lost their appetite and dropped weight; others went the opposite direction, eating more in an attempt to chase any satisfying sensation, gravitating toward intensely sweet, salty, or spicy foods.25PLOS ONE. Altered smell and taste: Anosmia, parosmia and the impact of long Covid-19 The social dimension gets overlooked: cooking for others, sharing meals, and the everyday pleasure of coffee or a favorite dish all become sources of frustration or grief rather than connection.
The health consequences can compound. People who compensate for lost flavor by increasing salt and sugar intake may raise their risk for cardiovascular disease and diabetes, turning a sensory problem into a metabolic one.26PubMed Central. COVID-19 loss of taste and smell: potential psychological repercussions Anxiety and depression are commonly reported alongside persistent chemosensory loss, which makes sense when you consider that the affected person has lost a fundamental source of daily pleasure with no guaranteed timeline for its return.