Can You Be Allergic to Weed?

Weed Allergy Symptoms, Diagnosis, and More

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Each year, more than 50 million Americans experience allergic reactions to all kinds of substances, including plants like cannabis (marijuana). Not only can you be allergic to weed, but a reaction can occur even after you have used pot for some time.

It is unclear how many people are allergic to weed. 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 differ depending 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 marijuana allergy are similar to symptoms of other allergies. They can vary depending on how you come in contact with the allergen.

Marijuana and hemp are different types of the cannabis plant. They differ in the amount of tetrahydrocannabinol—THC, the chemical that makes you "high"—they contain.

It's important to note that, if you have an allergy to marijuana, you may also be allergic to hemp. You may also be allergic to products containing cannabidiol (CBD), another chemical found in the cannabis plant.

Skin Contact

For some people, a marijuana allergy can cause a skin reaction that occurs when they touch or handle the plant or its flowers.

Symptoms of skin irritation might include:

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

Airborne Exposure

Like other plants, cannabis plants produce pollen that might be an airborne allergen for some people.

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

Symptoms of this type of reaction can include:

In some cases, mold may also be a culprit. Mold can develop on marijuana leaves during storage.


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 arise after consuming marijuana products include:

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


Allergy symptoms can vary, depending on how you interact with an allergen. For instance, skin contact can cause a rash, and airborne exposure can cause a runny nose. If you have symptoms of anaphylaxis (such as difficulty breathing, lightheadedness or rapid heartbeat), seek medical treatment right away.


Your immune system is to blame for a weed allergy—or any allergy, for that matter.

Your immune system is responsible for protecting your body from harm. When it detects something harmful, like a virus, it releases proteins called antibodies to defend itself. These antibodies then release chemicals that trigger symptoms like sneezing and runny nose, which are intended to help clear the "invader" from the body.

Allergic reactions happen when your immune system overreacts to substances that do not normally cause a problem. For some people, this may be tree or flower pollen. For others, weed.

It's important to note that if you have certain allergies, you might have an allergic reaction to weed as well.

There is a known cross-reactivity between tomatoes, peaches, bananas, citrus, eggplant, almonds, chestnuts, and weed. That means that if you're allergic to any of these foods, you may also have an allergic response to weed because it shares similar proteins. The reverse is also possible.

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

You may be surprised to have symptoms after using weed if you've done so for some time without any issue. Know that it's possible to develop an allergy after years of not having one. It's also possible to "outgrow" an allergy that you had when you were younger.


Allergic reactions occur when the immune system overreacts to generally harmless substances, like weed. Your body mistakes the substance as an invader and works to fight it off. Proteins in weed are also found in certain foods. Being allergic to one can make you allergic to the other.


In most cases, your doctor would make the diagnosis of marijuana allergy based on a details of your exposure and symptoms. They may also conduct allergy tests to confirm your exact allergy/allergies.

These tests aren't standardized for marijuana allergy, however. But in theory, your allergist could prepare an extract or mixture using the leaves, buds, and flowers of the plant that they can then use to perform a standard prick test.

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

Blood tests measure the levels of certain antibodies in your blood. This will help your allergist assess whether you're likely to be allergic to a specific substance.


If you suspect that you have developed an allergy to marijuana, the best thing to do is avoid the plant. This includes all forms of contact, including smoking, touching, eating, and environmental exposure.

If you have been using marijuana for medicinal purposes, you should speak with your doctor and seek professional medical advice. They might suggest alternative treatment options for your condition.

Sometimes, you may be unable to avoid airborne exposure to marijuana. This is often true for people who live with someone who smokes or who work in the cannabis industry. If that's the case, discuss options for treating your allergy with your doctor.

They might recommend antihistamines or decongestants to prevent or treat symptoms such as a runny nose and red eyes. They may also recommend wearing or using protective equipment like a respirator or mask to limit exposure.

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


The best treatment for any allergy is to avoid coming in contact with the allergen. If you're allergic to weed but can't avoid it, talk with your doctor about treatments that can reduce symptoms and options for limiting your exposure.


Some people may be allergic to weed. If you're allergic to marijuana, you may experience symptoms such as itching, redness, hives, or runny nose. Your symptoms may vary depending on whether you touch, eat, or breathe in smoke, dust, or pollen from the plant.

If you think you're allergic to weed, the best solution is to avoid it. If you use marijuana for medicinal purposes, consult with your doctor to see if there are alternative treatments you can try.

Frequently Asked Questions

  • Can you be allergic to THC?

    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 in cannabis-sensitive people.

  • Can marijuana cause anaphylaxis?

    Yes, but it's rare and has mainly been found to occur when someone with an allergy eats hemp seeds. 

8 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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  2. Allergy & Asthma Network. Marijuana allergy is no laughing matter.

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  4. Faber M, Van Gasse A, Sabato V, et al. Marihuana allergy: beyond the joint. J Investig Allergol Clin Immunol. 2015;25(1):70-72.

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Additional Reading

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