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Table of Contents
- What is THC?
- Can You Be Allergic to THC?
- What Can Trigger a THC Allergic Reaction?
- THC Allergic Reaction: What to Do
- Final Thoughts on THC Allergies
As legal cannabis markets have expanded across the United States, THC consumption has likewise increased, and so have THC allergies. It's not common—people are more likely to have a cannabis allergy, though that's also rare—but it is possible. What’s more, these allergic reactions can occur with multiple methods of consumption, and in some cases, from simply touching cannabis products that contain THC.
As with most things, a little knowledge goes a long way. Here’s what to understand about THC allergies in the unlikely event you or someone you know has an immune response to this particular cannabinoid.
What is THC?
Whether you’re familiar with the Cannabis sativa plant or not, you’ve probably heard about THC, or tetrahydrocannabinol. It’s the psychoactive compound in hemp and marijuana plants that’s responsible for the “high,” or the euphoria and stress relief people experience when they consume a THC product.
Under the 2018 Farm Bill, THC products derived from hemp plants—not marijuana plants—with a THC content of 0.3% or less became legal at the federal level. Some states followed suit in the years since, but others did not. In other words, these products may be federally legal, but individual state laws still apply. It’s important to know what’s what before attempting to buy or use hemp-derived THC products.
For states that permit recreational or medical use, THC products come in a truly dizzying array of options. You can find oils, tinctures, topicals, edibles, beverages, capsules, and products designed for vaping or smoking.
Some people use THC products for therapeutic benefits, like pain relief, sleep support, or relief for symptoms related to specific medical conditions, like cancer. Others use it recreationally, to relax, unwind, or socialize.
Regardless of intent, these effects are possible because this particular cannabinoid interacts with the human body through our endocannabinoid system.
The Endocannabinoid System
It might sound straight out of Star Wars, but the endocannabinoid system (ECS) isn’t a galactic council in some far-off solar system. Instead, it’s a biological system present in every human (and many animals as well), tasked with maintaining equilibrium throughout the body. The ECS regulates various bodily functions, including mood, appetite, sleep, stress response, immune response, pain levels, and more, working continuously behind the scenes to promote balance.
There are three parts to the ECS:
- Endocannabinoids are naturally produced compounds that are remarkably similar to phytocannabinoids in the cannabis plant. These compounds are essentially signal senders that prompt your body into a specific action.
- Receptors throughout the body interact with both endocannabinoids and phytocannabinoids.
- Enzymes break down cannabinoids after they bind to receptors.
THC forms a powerful bond with CB1 receptors, which are primarily located in the brain. That’s why it elicits such a significant psychoactive effect (and why some people find it effective for managing pain, nausea, and appetite).
Now, what about allergies to THC specifically?
Can You Be Allergic to THC?
You can indeed be allergic to THC itself. Most cannabis-related allergies are an immune response to other parts of the plant, like pollen, terpenes, and even mold. But THC allergies, though rare, are possible. And it happens just like any allergy: a dramatic overreaction.
Signs and Symptoms of a THC Allergy
If you have an allergic reaction to THC, symptoms and severity can vary. Some people may get a little itchy. Some people can develop a severe case of hives. In the most serious instances, which are also the rarest, anaphylaxis can occur.
People with a cannabis allergy tend to experience these symptoms within 30 minutes or so of exposure, whether it's ingested, inhaled, or on the skin. Here's how it happens.
The body’s immune system decides THC is a threat and mounts an immediate defense in the form of histamines. This unfolds with a physical reaction, such as itchy hives, swelling, a runny nose, sneezing fits, watery eyes, coughing, and wheezing, as the body works to expel this foreign invader. These symptoms can range from mild to moderate, and in very rare cases, they can be severe. It’s your body's noble attempt to protect you, even if there isn’t actually a threat.
This is a severe, life-threatening allergic reaction that happens fast and requires immediate medical attention. Fortunately, there are only a handful of documented cases relating to cannabis. Most cannabis allergy responses are milder—the itchy, sneezy variety that's more uncomfortable than anything else.
Allergies vs Intolerances
Allergies and intolerances are often easily confused, but the key difference lies in their underlying causes. An allergic reaction is triggered by the immune system in that mistaken-identity thing we covered above. A cannabis allergy can be broadly diagnosed with a skin prick test using cannabis extract, but they're often unstandardized. There are currently no commercially standardized tests for diagnosing cannabis allergies.
That's why it's challenging to get an accurate THC allergy diagnosis. Some people experience an allergic reaction because of other compounds in the cannabis product. This can include terpenes, which are naturally occurring compounds in cannabis that give the plant its distinctive flavors and scents, as well as pesticides or fertilizers, residual solvents, and mold or mildew.
Pro tip: Hemp is a bioaccumulator, so opting for organic hemp products like those here at Cornbread Hemp is a great way to limit exposure to potential contaminants that could trigger allergy symptoms. Most Cornbread Hemp products are USDA-certified organic, and all are federally legal in accordance with the Farm Bill. Plus, our sugarcane ethanol processing method and third-party testing mean safer, cleaner products.
Intolerances or sensitivities are different than allergic reactions. With cannabis and THC, these reactions relate to how your body processes these substances. It’s not an immune response—it’s just your body reacting poorly to certain forms of cannabis or even the dose.
If you have an intolerance to THC, you may get a headache, nausea, anxiety, a racing heart, feel fatigued, or dizzy. Anyone who’s overindulged in THC may find those symptoms familiar. The difference is consistency. If you have a THC intolerance, you’ll always experience these symptoms, even with small amounts of THC.
What Can Trigger a THC Allergic Reaction?
If you have a THC allergy, exposure to THC will trigger an allergic reaction. That means you could experience symptoms after being exposed to cannabis smoke, whether or not you partake. The same is true if you ingest THC in an edible, a tincture, or a capsule. THC is absorbed into the bloodstream through the digestive system and triggers the immune response. Even direct skin contact with a product that contains THC or exposure to cannabis pollen can be enough to trigger allergy symptoms.
Remember, it's possible that it's not the THC itself causing the allergic reaction. Even some individuals with underlying allergies to tomatoes, peaches, and hazelnuts may experience a response to THC due to the similarity in proteins between these plants. This is called cross-reactivity.
One study from 2018 also found that you're more likely to have a cannabis allergy if you're also allergic to dust mites, cat dander, or mold.
THC Allergic Reaction: What to Do
We'll reiterate that THC allergies are pretty uncommon, but it's always helpful to be aware of signs and symptoms and have a plan of action. If your reaction is mild to moderate, like mild swelling, hives, sneezing, or itchiness, stop your exposure—step outside if you were vaping or smoking, don't finish the edible, or wash off the topical product with lukewarm soap and water. An over-the-counter antihistamine can help relieve hives and swelling, and cold compresses can help relieve itchy skin.
It's also a good idea to track your symptoms. Make a note of what you used, how you consumed it, its potency, and your reaction, including its onset and duration. Then you can speak with your doctor about what happened and proceed with allergy testing to try to pinpoint the cause.
If you or someone else experiences a severe allergic reaction, such as difficulty breathing, swelling in the throat, a rapid heartbeat, or severe dizziness, call 911 or go directly to the emergency room. Do not try to treat allergic response symptoms of this severity on your own.
Remember that allergic reactions may worsen with repeated exposure. Consider yourself lucky if your first reaction was mild, and avoid using cannabis products until you can speak with a doctor or allergist about your reaction.
Final Thoughts on THC Allergies
THC allergies are rare, but they're real. If you have a THC or cannabis allergy, you may experience an allergic reaction based on any form of cannabis exposure, whether that's smoking, vaping, ingesting, or plain old skin contact. Your symptoms may include a skin reaction, such as itchiness, hives, and swelling, as well as adverse effects on your sinuses and eyes. If you are severely allergic, more concerning reactions can include swelling in the throat and difficulty breathing, which is when you should head straight to the ER.
While most reactions are mild and can be safely managed at home, take it for what it is: a warning. Your next allergic reaction to THC or cannabis is likely to be worse, so it's a good idea to avoid the use of cannabis in all forms until you can see a doctor or an allergist.
