Most people who lose their sense of smell after COVID recover it naturally, with about 96% reporting improvement within six months. But if you’re still struggling weeks or months later, the most effective thing you can do is a structured daily practice called olfactory training, which involves sniffing specific scents in a deliberate way to help your nose heal faster. Here’s what’s happening in your body, what works, and what to do if recovery is slow.
Why COVID Takes Away Smell and Taste
COVID doesn’t actually destroy the nerve cells that detect smell. Instead, the virus attacks the support cells surrounding those neurons, called sustentacular cells. These support cells provide structural and nutritional support to your smell-detecting neurons, and when they’re damaged, the neurons stop functioning properly even though they’re not infected themselves. Research published in Cell confirmed that the virus replicates in these support cells but spares the olfactory neurons and the smell-processing area of the brain. This is good news: it means the underlying hardware is intact, and recovery is a matter of those support cells healing and the system recalibrating.
What most people describe as losing their “taste” is usually a loss of flavor perception, which depends heavily on smell. Your tongue can still detect basic tastes like sweet, salty, sour, and bitter. But the complex flavors of food come from aromas traveling through the back of your throat to your smell receptors. When that pathway is disrupted, food tastes flat or “like cardboard” even though your taste buds are working fine.
Realistic Recovery Timelines
The odds are strongly in your favor. A large meta-analysis of nearly 3,700 patients found that 74% self-reported recovery of smell within 30 days, and 95.7% reported recovery by six months. Taste recovery ran slightly ahead, with 98% reporting improvement at six months.
For those with longer-lasting problems, recovery continues but slows down. Objective smell testing (which is more accurate than self-reporting) found that 42% of patients still had measurable smell dysfunction at 12 months, dropping to 28% at 24 months. Another study using identification tests found dysfunction in about 18% at one year, falling to just 3% at two years. So even if you’re months into this, your nose is likely still healing, just gradually.
How Olfactory Training Works
Olfactory training is the closest thing to a proven treatment for post-COVID smell loss. It’s essentially physical therapy for your nose: repeated, deliberate exposure to specific scents that helps your olfactory system rebuild its connections. A meta-analysis found that patients who did olfactory training had a 65% greater chance of recovery compared to those who didn’t.
The standard protocol uses four scents: rose, eucalyptus, lemon, and clove. You can buy essential oils of each or purchase a pre-made olfactory training kit. Here’s the routine:
- Frequency: Twice daily, ideally once in the morning before breakfast and once in the evening before bed
- Duration per scent: Hold each jar a few inches from your nose and sniff gently for 20 to 30 seconds, focusing your attention on what you’re trying to smell
- Total commitment: At least 24 weeks (six months), though many people continue longer
The mental focus matters. While sniffing, try to recall what that scent used to smell like. Visualize a lemon, a rose, a clove. This cognitive engagement helps your brain re-map the neural pathways involved in smell recognition. Don’t be discouraged if you smell nothing at first, or if what you smell seems “wrong.” Distorted perception is actually a sign that your system is rewiring.
Some research suggests that combining olfactory training with anti-inflammatory supplements like palmitoylethanolamide and luteolin may improve outcomes beyond training alone. Pharmacological treatments like corticosteroids, nasal irrigation, and other medications have not shown significant effectiveness for post-COVID smell loss and carry side effects that make them a poor first choice.
Supplements That May Support Recovery
Omega-3 fatty acids show promise for nerve repair. A randomized controlled trial found that 1,800 mg per day of fish oil for six months produced measurable nerve regeneration compared to placebo. While this study focused on peripheral nerves in diabetes rather than smell nerves specifically, the underlying mechanism of nerve fiber regrowth is relevant. Omega-3s are safe for most people and have other health benefits, making them a reasonable addition to your recovery plan alongside olfactory training.
PRP Injections for Persistent Cases
For people who’ve had smell loss for many months without improvement, platelet-rich plasma (PRP) injections into the nasal cavity are showing strong results. PRP uses growth factors from your own blood to stimulate tissue repair. In a prospective study with one-year follow-up, 87.5% of patients who received PRP injections met the threshold for clinically meaningful improvement, compared to just 31.2% of those who didn’t. PRP injection was an independent predictor of recovery even after accounting for age, gender, and how long smell had been lost.
This isn’t a guaranteed fix. Not every patient responds, and the degree of improvement varies. But for people who’ve been doing olfactory training for six months or more without adequate progress, PRP injections are worth discussing with an ENT specialist.
Dealing With Distorted Smell (Parosmia)
Some people don’t lose their smell entirely. Instead, they develop parosmia, where familiar things smell rotten, chemical, or just deeply wrong. Common triggers include coffee, onions, garlic, fried or roasted meats, eggs, bell peppers, and toothpaste. The distortion tends to be worst with foods cooked at high temperatures, because browning reactions release volatile compounds that are particularly problematic for a recovering olfactory system.
Parosmia is typically a sign that your smell neurons are regenerating but haven’t fully recalibrated yet. It’s a frustrating phase, but it usually means you’re on the path to recovery. In the meantime, these strategies can help:
- Cook at lower temperatures. Poaching, steaming, and sous-vide produce fewer of the volatile compounds that trigger distortion. A cold poached chicken breast is often tolerable when roast chicken is unbearable.
- Eat food cool or at room temperature. Hot food releases more aroma molecules. Letting things cool down before eating reduces the olfactory intensity.
- Keep a list of safe and trigger foods somewhere visible, so family members or housemates know what to avoid cooking around you.
- Add spices that parosmia sufferers tolerate well: cinnamon, clove, ginger, fennel seed, black pepper, and allspice are commonly reported as safe and can make bland food more interesting.
- Play with the basic tastes. Combining salty and sweet, or salty and sour, adds dimension to food even when flavor perception is off. Texture variety (crunchy with creamy, for example) also helps.
- Use a nose clip for meals that are especially difficult. Swimmer’s nose clips work well and can provide real relief when distortion is severe.
Having a support partner sit with you during meals, especially when you’re testing new foods, can make the experience less isolating. Keep a palate cleanser or drink nearby to wash away any offensive taste quickly.
Putting It All Together
Start olfactory training as soon as possible and commit to at least six months. Add omega-3 supplementation as a low-risk complement. If parosmia develops, adjust your cooking methods and food temperatures rather than forcing yourself through triggering meals. If you’re still experiencing significant smell loss after six months of consistent training, ask an ENT specialist about PRP injections or other interventions. The recovery curve is long but it bends strongly toward improvement, even two years out some people are still gaining ground.