Most people recover their sense of smell after COVID within a few weeks, but a significant number don’t. Psychophysical testing shows that roughly 27% to 42% of people still have measurable smell dysfunction a full year after infection, and about 28% still test abnormally at two years. The good news is that the olfactory system can regenerate, and there are proven techniques to help it along.
Why COVID Takes Your Smell Away
The virus doesn’t typically destroy your smell-detecting nerve cells directly. Instead, it infects the support cells surrounding them, called sustentacular cells. These cells express the receptor (ACE2) that SARS-CoV-2 uses to enter, making them the primary target in your nasal lining. When these support cells become inflamed, immune cells flood into the area and the nerve cells lose the ability to detect odors properly, even though they’re technically still alive. The genes responsible for producing odor receptors essentially get switched off by the surrounding inflammation.
This is actually encouraging. Because the neurons themselves are largely intact, recovery is a matter of calming inflammation, restoring the support cell environment, and retraining the neural pathways rather than regrowing nerve cells from scratch.
Why Your Taste Feels Gone Too
What most people call “taste” is mostly smell. When you chew food, aromas travel up the back of your throat to your smell receptors. This is called retronasal olfaction, and it’s responsible for the complex flavors of coffee, chocolate, herbs, and cooked food. If your smell is impaired, food will taste flat and lifeless even though your tongue still works.
That said, COVID can also affect true taste independently. Research involving nearly 11,000 participants confirmed that some people lose the ability to detect sweet, salty, sour, and bitter on the tongue itself, separate from smell loss. You can test this at home: if you can detect sugar dissolved in water or salt on your tongue but food still tastes like nothing, your issue is primarily smell-based. If you can’t even taste sugar or salt, your taste nerves are also affected.
Olfactory Training: The Most Effective Tool
Smell training is the single best-supported intervention for recovering your sense of smell. The protocol is simple. You sniff four distinct scents, twice a day, for at least 12 weeks. The traditional scent categories are rose, lemon, eucalyptus, and clove, chosen because they each activate a different type of smell receptor.
To do this at home, get four small jars and fill each with a strong-smelling substance from those categories. Essential oils on cotton balls work well. Twice a day, hold each jar close to your nose and sniff gently for about 20 seconds. While you sniff, actively try to remember what that scent is supposed to smell like. This mental effort matters because it strengthens the neural connection between your nose and brain.
Don’t be discouraged if you smell nothing at first. The training works by stimulating regeneration over weeks and months. Some people notice improvement within the first month; others need the full 12 weeks or longer. Consistency is more important than intensity.
Nasal Corticosteroids
Nasal steroid sprays can help by reducing the inflammation that’s disrupting your smell receptors. In clinical trials, patients using a steroid nasal spray alongside olfactory training recovered normal smell at roughly double the rate of those doing training alone. One trial found 49% of the steroid group returned to normal smell versus 21% of controls. Another showed 54% versus 43%.
These sprays are available over the counter in most countries. The approach works best for noses that feel congested or runny. If your nose feels dry, a nasal rinse with a steroid dissolved in saline may be more appropriate. Either way, courses typically last three to four weeks.
Vitamin A Nasal Drops
Vitamin A plays a direct role in regenerating olfactory receptor neurons. In a controlled study, 37% of people with post-infectious smell loss improved with topical vitamin A drops compared to 23% who did training alone. The combination of vitamin A drops plus olfactory training produced significantly greater improvement in the ability to detect and distinguish odors.
The protocol used in research involves applying 10,000 IU of vitamin A in drop form into each nostril daily, with your head tilted back, for eight weeks. This is a topical application, not an oral supplement, and the distinction matters because it delivers vitamin A directly to the tissue that needs it. Ask a pharmacist about compounding vitamin A drops if they’re not available commercially in your area.
What About Other Supplements?
Alpha-lipoic acid got early attention because of its antioxidant and nerve-regenerating properties. An older study suggested it helped 61% of people with post-viral smell loss. However, a double-blind randomized trial specifically in COVID patients found no benefit. Patients taking 600 mg daily for 12 weeks showed no difference in smell recovery compared to those doing olfactory training alone. Based on current evidence, it’s not worth the investment.
Omega-3 fatty acids have theoretical appeal because of their anti-inflammatory effects, and there’s reason to believe they support olfactory system regeneration. But strong clinical trial data specific to post-COVID smell loss is still limited, so omega-3s are best thought of as a reasonable addition to your overall approach rather than a primary treatment.
Managing Parosmia
Some people don’t just lose smell. They get it back wrong. Parosmia is when familiar things smell distorted, often disgustingly so. Coffee, onions, garlic, fried meats, eggs, and bell peppers are the most common triggers. Even trace amounts of onion or garlic powder in processed foods can set it off. The issue is linked to the Maillard reaction, the chemical process that happens when food browns at high temperatures. Sautéing, roasting, deep frying, and baking to the point of browning all release the specific volatile compounds that trigger parosmia.
If you’re dealing with this, practical adjustments help:
- Cook at lower temperatures. Steaming, boiling, and poaching produce far fewer trigger compounds than roasting or frying.
- Eat food cold or at room temperature. Hot food releases more aromatic compounds. A cold chicken sandwich may be tolerable when a hot roast chicken is not.
- Keep a running list of safe and trigger foods. Post it somewhere visible, especially if you share a kitchen. Revisit it regularly, because triggers change as you heal.
- Build meals from bland safe foods, then add interest. Plain rice, pasta, and yogurt are commonly tolerated bases. Spices like cinnamon, ginger, black pepper, and fennel seed are often safe and add flavor through pathways that bypass the damaged smell receptors.
- Mix textures and true tastes. Combining crunchy with creamy, salty with sweet, or sour with savory makes meals more satisfying when complex flavors are absent. Colorful plating also helps with appetite.
- Have a “palate cleanser” ready. When trying new foods, keep a drink or neutral food nearby to wash away any offensive taste quickly. Having someone sit with you during food experiments reduces the anxiety around eating.
Parosmia is generally a sign that your olfactory neurons are regenerating but haven’t fully rewired yet. It’s unpleasant, but it typically means you’re moving in the right direction.
Stellate Ganglion Block
For people who’ve tried everything and still have significant loss after many months, a stellate ganglion block is a newer option worth knowing about. This is an injection of local anesthetic into a nerve cluster in the neck that helps regulate blood flow and inflammation in the head and face. In a case series of six patients with long-term COVID-related smell and taste loss, five experienced meaningful improvement. One patient recovered 85% of smell and 80% of taste by the three-month follow-up. One patient had no improvement at all.
Side effects are temporary but notable: drooping eyelid, red eye, hoarseness, and difficulty swallowing can occur for hours after the procedure. This is a specialist procedure performed by anesthesiologists or pain medicine doctors, and it’s still considered investigational for smell loss specifically.
Realistic Recovery Timelines
Self-reported recovery rates tend to be optimistic. Only about 5% of people report persistent smell problems at six months. But when those same people take objective smell tests, nearly 69% still show measurable deficits at six months. By 12 months that drops to 27% to 42%, and by 24 months, about 28% still have detectable dysfunction. The gap between what people report and what tests show suggests that partial recovery feels like full recovery to many people, which is reassuring in its own way.
The practical takeaway: commit to olfactory training for at least 12 weeks before judging results. Add nasal steroids if inflammation seems to be a factor, and consider vitamin A drops for an additional boost. Most improvement happens in the first year, but measurable gains can continue well into the second year after infection.