Losing taste and smell is a common symptom of COVID-19, but other viruses can also cause it. Smell training may restore some people’s smell and taste, but the loss may be longer lasting for others.

Losing the ability to taste and smell is more than an inconvenience. It diminishes a person’s quality of life and exposes them to greater risk as they cannot detect smoke, gas, and other hazards.

Loss of taste and smell is a common symptom of COVID-19, occurring in 41–96% of people. It can be one of the earliest symptoms and, for some, the longest lasting.

The article explores more causes of loss of taste and smell, how to get it back, how long it can last, and current research.

A person eating noodles, who may have lost their taste or smell.Share on Pinterest
Cécile Fourcade/Stocksy

The most common causes of the loss of taste and smell are sinus and nasal diseases, viruses, and trauma to the nasal area.

Scientists believe that SARS-CoV-2, the virus that leads to COVID-19, causes the loss of smell and taste by suppressing the smell receptors in the nose that detect odors and the nerve impulses that transmit information about odors to the brain.

If a person experiences a loss of smell in this way, their taste is also usually affected. This is because the body detects the flavor of food and drink through smell and taste.

COVID-19 variants differ in how frequently they affect taste and smell. Less than 25% of people who get the Omicron variant also lose their sense of smell.

Learn more about loss of taste and smell with COVID-19.

Other viruses can cause the loss of taste and smell, including:

Additional factors that cause the loss of taste and smell include:

A person with ongoing loss of taste and smell can work with a physician or a specialist. A doctor can adjust medication if this is causing the issue.

Surgery can help restore taste and smell for individuals who have polyps. People have tried using the following medications to get taste and smell back, although there is little data that proves they are effective:

Below are some other ways a person may be able to bring back their sense of smell and taste.

Smell training

Olfactory training, also known as smell training, involves smelling four different scents daily to help restore a person’s sense of smell.

Unlike many other systems in the body, the olfactory system — the sensory system used for smelling — can adapt and regenerate. Exposure to odors through smell training helps enhance this process.

It may be most effective for people who have lost their sense of smell due to infection. One 2016 study involving more than 100 people found that 71% of those with postinfectious olfactory dysfunction improved with olfactory training over 1 year.

A person can try smell training at home by following these steps:

  1. Collect a sample from each of the four categories of smell: This includes flowery — such as rose, fruit — such as lemon, spicy — such as clove, and resinous — such as eucalyptus.
  2. Sniff each scent continuously for 20–30 seconds: Take lots of quick “bunny sniffs” instead of breathing deeply into the lungs.
  3. Follow this routine twice a day: Typically in the morning and evening.

Smell training typically takes about 6 months. People can use commonly available ingredients to stimulate their smell, such as ground coffee, black pepper, or fresh herbs.

They can soak cotton pads with odor solutions and place them in small jars for repeated use. Changing to a different set of smell samples every few months may also be beneficial.

The smell loss charity AbScent in the United Kingdom offers more information about the smell training technique.

General tips

Adopting healthy practices can also help a person get their taste and smell back. These include:

  • Changing diet: People have found that varying the flavors and colors of food makes it more interesting.
  • Adding spice: Use fresh herbs, peppers, ginger, lemon, lime, and spices to add stronger flavors to food without depending too much on sugar and salt.
  • Following good oral hygiene: Floss and brush regularly to prevent gum disease and mouth infection from changing the way food tastes.
  • Quitting smoking: Tobacco can interfere with taste and smell.
  • Reducing alcohol use: Drinking less alcohol or eliminating it completely can help normalize the sense of taste.

If a person loses their ability to taste and smell due to respiratory infections, these senses usually return after the disease runs its course.

Many people who lose their ability to taste and smell due to COVID-19 regain it in a few weeks. However, this may take months or longer for up to 7% of people.

A 2022 meta-analysis of 18 studies found that 74% of people who lost their sense of smell and 79% of people who lost their sense of taste said they got it back within 30 days. It also found that 96% of those without smell and 98% of those without taste reported getting their taste and smell back in 180 days.

People have lost taste and smell permanently due to injuries, infections, and other causes.

Researchers think that smell and taste loss lasting longer than 18 months after contracting COVID-19 may be permanent, but it is too soon to know for certain.

Scientists continue looking for new information that may help people get their taste and smell back.

For example, a 2021 study found that taking a 1,000-milligram supplement of turmeric while a person had COVID-19 swiftly regained smell and taste. However, the study only involved two participants, meaning more comprehensive studies are needed to assess whether this is a causal link.

Additionally, researchers are studying the effectiveness of using a neurotrophic drug called cerebrolysin to treat people with long lasting taste and smell loss.

A 2020 pilot study suggested platelet-rich plasma (PRP) may be effective in treating smell and taste loss, especially for people with moderate yet persistent loss. Scientists are planning further clinical trials to assess optimal dosage and application.

A person should speak with a healthcare professional if they experience a sudden loss of taste or smell.

If the loss of smell and taste continues without any improvement after 3 weeks, a person should speak to a doctor about treatment options.

Most people who develop a loss of taste and smell due to COVID-19 get it back. It can take from 30 days to 6 months for these senses to return.

However, according to researchers, as many as 1 out of 20 people who lost their sense of smell due to COVID-19 may not get it back.

COVID-19 is a common cause of taste and smell loss. Other common causes include sinus and nasal diseases, viruses, and trauma to the nasal area. Medications and other health conditions, such as Parkinson’s disease and cancer, can also contribute.

A person who experiences ongoing loss of taste and smell may be able to restore these senses by using a technique called smell training. This typically involves sniffing certain scents twice per day for six months. Some lifestyle changes may also help, such as modifying diet and quitting smoking.

Anyone who experiences loss of taste or smell for longer than three weeks should consult a healthcare professional.