Does an Onion in the Room Stop a Cold or Flu?

Throughout the centuries, people have relied on home remedies for colds. Placing a cut onion in the room of someone who is sick is one suggested "remedy" that has been passed down in some families and gets shared over social media every cold and flu season.

The idea is that onions have the ability to absorb bacteria and viruses and will actually "pull the germs out" of the sick person. There is no truth to any of these claims. The National Onion Association, in fact, has said that there is no scientific evidence a cut raw onion absorbs germs or rids the air of toxins and poisons.

This article will talk about the humble onion and how there is no proof that it can help prevent the flu or the common cold.

Verywell / Laura Porter

Why It Doesn't Work

Onions do not provide a good environment for bacteria or viruses to multiply or live. Even if an onion could draw or remove germs from someone (which is scientifically impossible), there's nothing special about an onion that would kill these organisms.

On the other hand, bacteria and viruses think your body is a great place to be. When you get sick, germs enter your body and multiply. Your body acts as a "host." This means your body is providing a place where the bacteria or virus can grow and spread. Fortunately, your body knows how to fight back.

When your immune system notices these invading germs, it releases antibodies (special proteins that attack foreign substances entering the body) to try to fight them off. This causes inflammation and the symptoms you experience when you get sick, such as excess mucus, cough, sore throat, and headache. You need your immune system to help you get on the road to feeling better and beating an infection.

Where This Idea Originated

The folk remedy to keep raw onions in the room when you are sick dates back to the 1500s, according to the National Onion Association. During the bubonic plague, cut onions were placed around homes to keep people from contracting the deadly illness.

At the time, it was believed that all illnesses were spread through the air. These clouds of disease—or miasmas—were thought to exist when the air smelled bad.

In more recent history, people used onions in a room to try to protect themselves against the 1918 flu pandemic. In one instance, a doctor had his patients place cut onions in their homes. The patients all stayed healthy while others in the community did not.


While many home remedies involve placing a cut onion in the room of someone who's sick, there is no evidence that this works. Onions do not have the ability to absorb germs and toxins floating around in the room. Instead, your immune system attacks any invading viruses or bacteria entering your body. It helps your body recover from sickness.

Throughout history, many people believed onions had the power to make sick people feel better or even prevent them from getting sick. But the best way to fight a cold or flu is to follow your doctor's recommendations.

A Word From Verywell

Placing an onion in the room will not treat a cold or keep you from getting one. Washing your hands regularly, avoiding crowds during flu season, eating a healthy diet, exercising, and getting plenty of sleep can help you stay healthy.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Onion Association. Onions & flu.

  2. MedlinePlus. Viral infection. Published August 11, 2021.

  3. UCLA Fielding School of Public Health. Competing theories of cholera.

By Kristina Duda, RN
Kristina Duda, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention.