Allergic to Marijuana: Symptoms, Causes, and Treatment

Cannabis allergies have become more common in recent years

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You can be allergic to weed—even if your first reaction only comes after using or being around cannabis (marijuana) for some time. Symptoms of a weed allergy vary and may include skin rash, sore throat, watery eyes, and shortness of breath.

Weed allergy is thought to be rare, though it is unclear exactly how many people it affects. As a growing number of states legalize the use of medical and recreational marijuana, it is likely there will be a better understanding of how widespread the allergy is.

This article explains the symptoms of a weed allergy, which can depend on whether you handle it, smoke it, or consume it. You'll also learn about the challenges of diagnosing the allergy and what you can do if you have one.

marijuana allergy symptoms

Verywell / Cindy Chung

Weed Allergy Symptoms

Symptoms of a cannabis allergy are similar to symptoms of other allergies and can differ depending on how you come in contact with the allergen. And as with most allergies, the severity of symptoms, when they start, and how long they last can be a little different for each person. 

Most marijuana allergy symptoms come on fast, with people reacting within minutes. Others may not notice symptoms for hours or even a couple of days.

If you have a weed allergy, you may experience a reaction after using marijuana for the first time or after even years of use. It's also possible to "outgrow" an allergy over time.

Skin Contact

A marijuana allergy can cause a skin reaction when a person touches or handles the plant or its flowers.

Symptoms of skin irritation from a weed allergy could include:

  • Itching
  • Redness
  • Rash or hives
  • Dry, scaly skin

A person with a weed allergy can also get skin symptoms after using topicals, like creams and CBD oil. 

Marijuana, Hemp, and CBD

Marijuana and hemp are different types of cannabis plants. If you are allergic to weed, you could also be allergic to hemp. You could also have an allergic reaction to products that contain cannabidiol (CBD), another chemical found in the cannabis plant. 

Airborne Exposure

Like other plants, cannabis makes pollen that can be an airborne allergen for some people.

Dust from the industrial processing of hemp or marijuana can also trigger an allergic reaction, as can inhaling marijuana smoke—even if you're just breathing it in secondhand.

Symptoms of this type of reaction can include:

In some cases, mold that sometimes develops on marijuana leaves during storage can cause allergy symptoms.


As the legalization and use of medical marijuana have become more widespread across the United States, so has the popularity of cannabis-infused edibles.

Symptoms of a weed allergy that may come on after consuming marijuana products include:

While it is rare, there have been reported cases of anaphylaxis from eating hemp seeds. This is a life-threatening allergic reaction that causes breathing problems and a dangerous drop in blood pressure.

Why Am I Allergic to Weed?

If you’re having an allergic reaction to marijuana, you’re reacting to something in the plant or even an allergen on the plant, like pollen. You could also be allergic to a substance that’s been added to a marijuana product—for example, a fragrance added to CBD oil or an ingredient in an edible).

Allergic reactions happen when your immune system overreacts to substances that do not normally cause a problem. For some people, this can be pollen from a tree or flower. For others, it’s something in weed.

When your immune system detects something it deems harmful, it releases proteins called antibodies to help clear the "invader" from the body. In some people, weed may be identified as such an enemy.

The antibodies release chemicals that trigger symptoms like sneezing and runny nose.

Am I Allergic to THC?

Tetrahydrocannabinol (THC) is the substance in cannabis plants that makes you "high." While marijuana has enough to have this effect, hemp has very little (0.3% or less) and CBD has none.

Specific proteins in cannabis pollen and cannabis smoke are known to trigger cannabis-related allergies. While THC is not currently considered a cannabis allergen, more research is needed to determine what role (if any) THC plays in triggering allergic responses.

Food Allergies and Weed Allergy

There is a known cross-reactivity between certain foods and weed. If you're allergic to one of the following, you could be allergic to weed, and vice versa. This is because weed and these foods have similar proteins.

  • Almonds
  • Apples
  • Bananas
  • Chestnuts
  • Eggplant
  • Grapefruit
  • Peaches
  • Tomatoes

In one study, marijuana use was also associated with the development of allergies to molddust mites, plants, and cat dander.


In most cases, your provider can make the diagnosis of marijuana allergy just by talking to you about your exposures and symptoms. They may also do allergy tests to confirm what you’re allergic to. 

These tests are not standardized for marijuana allergy, but your allergist may want to run them anyway. They can make an extract or mixture using the leaves, buds, and flowers of the plant and use them to perform a standard allergy prick test.

This test involves applying a small amount of allergen to a break in the skin and monitoring any reaction that occurs.

There are also blood tests that measure the levels of certain antibodies in your blood. An allergist uses the results to figure out which substances you’re having a reaction to. 

Treatment for Weed Allergy

If you think that you have developed an allergy to marijuana, the best thing to do is avoid it. This means no longer smoking weed or consuming edibles, as well as refraining from touching it and having any secondhand exposure to it.

If you are using marijuana for medicinal purposes, this may be difficult. Talk to your provider. They might suggest alternative treatment options for your condition.

If you have had a severe reaction to marijuana, you might need to carry an epinephrine auto-injector (Epi-pen) at all times. This medication acts quickly to treat severe allergy symptoms, such as trouble breathing and a drop in heart rate. Some people need to carry more than one Epi-pen just to be safe.

When You Can't Avoid Exposure

Sometimes, avoiding airborne exposure to marijuana is challenging. This is often true for people who work in the cannabis industry or live with someone who smokes pot.

In these cases, you can try:

  • Taking antihistamines or decongestants to prevent or treat symptoms, such as a runny nose and red eyes
  • Using an air purifier
  • Opening a window to ventilate your space
  • Wearing gloves or a face mask when you’re handling cannabis or are around someone who is smoking


It’s possible to be allergic to weed, but researchers don’t know how common it is. If you're allergic to marijuana, you may get symptoms such as itching, redness, hives, or a runny nose. The symptoms might be different depending on whether you touch, eat, or breathe in smoke, dust, or pollen from the marijuana plant.

If you think you're allergic to weed, avoiding it will help prevent symptoms. If you use marijuana for medicinal purposes or can’t avoid it because you live with someone who uses it or you work around it, talk to your provider about steps you can take to manage your allergy. 

10 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.
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Additional Reading

By Angela Morrow, RN
Angela Morrow, RN, BSN, CHPN, is a certified hospice and palliative care nurse.