Should you use cannabis when you have a cold or flu?

Winter is officially most people’s least favorite season, and it’s likely that the onset of colds and flus factor in. While colds tend to be milder and come on gradually, an attack of the flu is usually quite sudden, bringing headaches, body pain, and serious lethargy. With tossing and turning at night, a swollen and runny nose, and noisy mouth-breathing, these common respiratory illnesses can leave you feeling miserable for a week or more.

We each have our own arsenal of go-to remedies when feeling sick, whether it’s hot toddies or steaming bowls of soup. And for some cannabis enthusiasts, weed can ease the discomfort associated with colds and flus, and help pass the time. 

But how does cannabis impact a body that’s fighting off a cold or flu? Is it safe to smoke cannabis if you’re wheezing and coughing? Can weed help alleviate cold or flu symptoms, or is that just wishful thinking?

Let’s explore whether weed can be helpful or harmful when you’re struck with a cold or a case of the flu.

How can cannabis impact the respiratory system?

There’s robust evidence to suggest that smoking cannabis regularly, even when not sick, can lead to unwanted respiratory symptoms such as a cough, phlegm, wheezing, shortness of breath, throat inflammation, and worse asthma symptoms if you have that condition. 

These negative effects arise from irritation caused by the heat of smoke, which can harm delicate respiratory tissue in the lungs and airways. More serious damage may arise among those who smoke cannabis frequently (like several times per day.) 

Smoking weed on a sporadic basis may still provoke respiratory symptoms like temporary coughing or a burning throat, but it’s less likely to cause long-term damage to the lungs. 

When it comes to vaping, research shows that it lowers the risk of chronic respiratory symptoms when compared to smoking. In one study, vaporizer users were 40% less likely to report coughing, phlegm, and chest tightness than those who smoked cannabis. In another study, 12 of 20 people switched from smoking to vaping for 30 days and found that their respiratory symptoms and lung function improved.

In other words, smoking weed regularly can lead to detrimental effects on your throat, lungs, and airways, even when not sick with a cold or flu, while vaping appears to have less negative effects on the respiratory system. 

Lighting up when you’re super congested and coughing like a seal probably isn’t the greatest idea.

Can cannabis make you feel worse when you have a cold or flu?

Colds and flus are infections that affect the respiratory system, including the nose, throat, mouth, airways, and lungs. Some telltale symptoms mirror those of chronic cannabis smokers—an inflamed throat, coughing, shortness of breath, and excess phlegm. 

It makes sense that if your throat and lungs are already irritated, smoking may exacerbate unpleasant symptoms you’re already experiencing. There seems to be a general consensus among experts and consumers alike that it’s best to give the respiratory system a break when you’re fighting off an infection and instead opt for edibles, tinctures, or topicals.

Dr. Jordan Tishler, President and CEO of InhaleMD and President of the Association of Cannabinoid Specialists, strongly advises against inhaling cannabis if you’re laying low with a cold or flu. The heat, particles, and toxins inhaled during smoking may provoke wheezing, cause difficulty breathing, and can reduce the body’s natural defenses against viruses.

“In general, I would advise avoiding smoking while sick—and frankly other times too,” said Tishler. “Other forms of inhalation, like vaporizing flower, are also likely to make you feel worse, so I would also recommend against those.” 

Tishler also said that many patients at his practice who have asthma or COPD find that inhaling cannabis makes their condition worse—and that’s not even when they have a cold or flu. 

“Likely this would only be worse when a person is infected,” he said.

“Overall, I would say that using cannabis by non-inhaled means while sick with a respiratory illness is safe, but may not be a net positive,” said Dr. Tishler. “There’s really no research on this yet. I’m certain that some people might say that they feel better overall if they’re intoxicated while sick, but others may find it to be unpleasant.”  

Other effects of weed might be undesirable when you’re feeling under the weather. The flu, in particular, can leave you feeling weak and dizzy, and some weed strains can cause lightheadedness. Combine the two and your situation could get worse. It goes without saying that experimenting with high doses of weed is ill-advised when you’re fighting off the flu.

Can cannabis ease cold and flu symptoms?

While there is little research that specifically explores the effects of cannabis on colds and flus, there’s a lot of research to support the idea that weed can ease aches and pain, help with insomnia and sleeplessness, increase appetite, and ease headaches, all common symptoms of colds and flus. 

Interestingly, research also shows that infrequent cannabis smoking may help to temporarily open up airways for 15-60 minutes, a phenomenon known as bronchodilation. This research suggests that infrequent smokers may be able to draw deeper breaths for a brief period after smoking, which, in turn, could offer temporary relief from shortness of breath or wheezing, though it may be subtle and short-lived.

According to Dr. Dustin Sulak, cannabis may also have some unique benefits for those with a cold or flu. Weed may help dry out upper respiratory secretions, similar to the way it can dry out the mouth (aka cottonmouth). 

Cannabis can also act as an expectorant, helping to clear phlegm from the lungs and throat. However, Sulak cautions against inhaling cannabis if you’re experiencing any negative respiratory symptoms. 

Anecdotes for using cannabis to ease cold and flu symptoms

We asked some cannabis consumers for their thoughts on using weed when sick with a cold or flu. Overwhelmingly, the responses were positive, and many people shared anecdotes about how cannabis can help with sleep, aches, appetite, and even passing the time.

“Cannabis has given me relief from restlessness and an inability to sleep well when I’m plagued with body aches or fever,” said Jenna Carson, consultant at Music Grotto. “Some people swear by nighttime cold syrups, but they knock me out too long. I like the fact that the THC in marijuana… does not last as long as cold medicine so I avoid waking up super groggy,”    

For Jared Sherman of Mellow Moose Farms, cannabis can help elevate you above the misery of feeling sick. “In my opinion, if you have to feel like shit, you might as well be high as shit,” he reflected. “Use edibles, tinctures, or topicals, and give your body an opportunity to deal with the infection and heal itself. Avoid any unnecessary coughing if at all possible—your throat will thank you.”

Emma Stone

Emma Stone is a journalist based in New Zealand specializing in cannabis, health, and well-being. She has a Ph.D. in sociology and has worked as a researcher and lecturer, but loves being a writer most of all. She would happily spend her days writing, reading, wandering outdoors, eating and swimming.

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