Nausea can be debilitating, whether it’s caused by chemotherapy, chronic illness or medications, finding effective relief is essential. For many, cannabis has emerged as an option when other treatments fall short.
In this article, we’ll explore how cannabis and the cannabinoids THC and CBD may help manage nausea. You’ll learn how cannabinoids work in the body, what the research says about their effectiveness and how to use cannabis for nausea with confidence and care.
Whether you’re exploring cannabis for the first time or looking for safer, more effective options, this guide will help you better understand how THC and CBD may provide meaningful nausea relief.
At EO, we’re working to help cannabis find its place as a responsibly provided, evidence-based medical treatment. We’re led by medical doctors, healthcare professionals and cannabis industry leaders, and our clinical team has deep experience in supportive oncology. We provide affordable, federally legal medical and wellness cannabis products.
Cannabis has been used to relieve queasiness, but today we’re beginning to understand why it works, thanks to advances in neuroscience and cannabinoid research.
At the center of cannabis’s anti-nausea potential is the endocannabinoid system (ECS), a complex cell-signaling system found throughout the brain and body. The ECS helps regulate numerous physiological processes, including appetite, mood, pain and nausea.
One of the most important components of this system is the CB1 receptor, which is found in high concentrations throughout the central nervous system, including a region of the brainstem called the dorsal vagal complex (DVC).
The DVC plays a key role in nausea and vomiting. It integrates signals from the gastrointestinal system and brain, coordinating reflexes that lead to queasiness or emesis (vomiting). When cannabinoids like THC bind to CB1 receptors in the DVC, they appear to disrupt this reflex, effectively reducing the brain’s nausea response.
This mechanism is particularly relevant for people undergoing chemotherapy or dealing with chronic GI conditions, where nausea can be persistent and resistant to standard medications.
Beyond the ECS, cannabinoids also appear to influence serotonin, a neurotransmitter closely tied to nausea. Many anti-nausea medications, such as ondansetron (Zofran), work by blocking serotonin receptors—specifically 5-HT3 receptors—to reduce nausea.
CBD, though it doesn’t strongly bind to CB1 receptors, has been shown to modulate serotonin release, particularly in the brainstem. This modulation may be one reason why CBD can reduce nausea on its own—especially nausea related to anxiety, motion sickness, or anticipatory triggers.
Together, THC and CBD act on complementary pathways: THC binds to cannabinoid receptors to suppress the physical urge to vomit, while CBD may help calm the psychological and neurochemical processes that initiate nausea.
When used together, THC and CBD often provide broader relief than either compound alone. THC is typically more potent for acute nausea, but it can come with side effects like dizziness, anxiety, or temporary impairment, especially at higher doses or in new users.
CBD helps mitigate these side effects, providing a calming counterbalance to THC’s psychoactivity. CBD may also enhance the anti-nausea effects of THC through a phenomenon called the entourage effect, where multiple cannabinoids work together synergistically to produce more therapeutic benefit.
Many people find that full-spectrum cannabis (which includes a range of cannabinoids and terpenes) provides more reliable symptom control than isolated THC or CBD alone.
While conventional antiemetics like ondansetron, metoclopramide, and prochlorperazine are often first-line options, they don’t always work—and can come with side effects like headaches, constipation, or extrapyramidal symptoms.
Cannabis may offer a different mechanism of action, and for some, it works when other medications don’t. That said, it’s most often used as an adjunct, something added to an existing nausea treatment plan, particularly for refractory cases or when appetite stimulation is also a goal.
Because cannabinoids work on different brain pathways than serotonin-blocking drugs, they can be used together under clinician supervision.
Nausea and vomiting are among the most distressing side effects of chemotherapy, often leading to dehydration, malnutrition, treatment delays, and a reduced quality of life. While standard anti-nausea medications can help, they don’t always work for everyone. For some patients, THC offers an alternative that’s both effective and well tolerated under medical supervision.
The most commonly prescribed antiemetics in cancer care include, Ondansetron (Zofran), Metoclopramide (Reglan) and Aprepitant (Emend).
These medications block neurotransmitters that trigger nausea and vomiting signals in the brain. They are typically used in combination to manage acute (within 24 hours) and delayed (after 24 hours) nausea following chemotherapy.
However, some patients experience what’s known as refractory nausea—persistent nausea that does not respond well to first-line medications. In these cases, THC may offer additional relief by working through a different system entirely: The endocannabinoid system.
Studies have shown that THC-based medications may be effective —or in some cases more effective—than standard antiemetics, particularly in patients with difficult-to-treat symptoms. THC may be effective because of its dual action: It can relieve nausea and stimulate appetite, helping patients maintain body weight and nutritional intake during treatment.
While cannabis isn’t usually the first treatment oncologists reach for, it is increasingly used as a second-line or adjunctive therapy—especially when patients experience side effects from conventional medications, or when nausea persists despite a full antiemetic regimen.
Research suggests that combining THC with other antiemetics can offer synergistic relief. Because it operates through the CB1 receptors (rather than serotonin or dopamine pathways), THC may help cover gaps in symptom control and reduce the total dose of other medications needed, potentially minimizing side effects like sedation or constipation.
One of the most unique advantages of THC over traditional antiemetics is its ability to increase appetite. Appetite loss not only contributes to weight loss, but also undermines the body’s ability to heal and maintain strength during treatment.
THC activates CB1 receptors in the hypothalamus and gastrointestinal tract, leading to increased feelings of hunger, improved taste and smell sensitivity, and better food intake.
Cannabis does not treat or cure cancer. If you or someone you know is considering cannabis as part of their cancer care, it’s important to understand how it interacts with the body, potential effects and side effects and how to use it most responsibly. As with any medications, you should talk to your doctor about the benefits and risks of using cannabis before including it in your treatment plan.
The key to safe and effective THC use lies in personalized, medically guided cannabis care. Unlike over-the-counter supplements or unregulated cannabis products, clinician-guided care ensures that patients:
Cannabis, like any medicine, is not without risks. Understanding and managing side effects is essential, especially for medically vulnerable patients.
Most short-term side effects of cannabis are dose-dependent and more common with THC-dominant products. These include:
With low-dose, clinician-guided use, most people experience minimal issues. But THC can cause unwanted effects—especially in high doses or in people new to cannabis.
Too much THC can lead to anxiety, confusion, or paranoia. This is why we recommend starting with very low doses—especially if you’re new to cannabis or sensitive to its effects. Products with balanced THC:CBD ratios or low-dose formats (like inhalers or split-tab gummies) can offer more predictable, manageable relief.
Long-term risk of cannabis use include cardiovascular effects, harm to lung health (with smoking or vaping), mental health concerns, gastrointestinal problems and increased risk of cancer. Certain people should be especially cautious about THC use:
If you’re managing cancer or other serious conditions, it’s essential to talk to a cannabis-informed clinician.
Cannabis can be taken in many forms, each with different onset times, durations, and levels of control. For nausea relief, onset speed and dosing consistency are key.
Here’s a comparison of the most commonly used THC formats for nausea:
For people undergoing cancer treatment, fast-acting, easy-to-dose formats like sublingual drops or lozenges, gummies, or metered-dose inhalers are often best. These allow for quick symptom control without overmedicating.
Edibles can be useful for ongoing, background relief, especially overnight, but may be harder to titrate due to delayed onset.
Cannabis has real potential to help people struggling with nausea, whether it’s from chemotherapy, medications or chronic conditions.
Research shows that cannabinoids, like THC and CBD, interact with nausea-related brain pathways and can help reduce nausea and potentially increase appetite. THC provides the strongest anti-nausea effects, while CBD can complement it by reducing side effects and enhancing relief.
Using cannabis for nausea safely means understanding your options and working with a knowledgeable clinician. It also means choosing the right product, dose and delivery method based on your needs and experience level.
For cannabis users seeking a healthier and more reliable way to reap the medical benefits of cannabis, consider EO’s Cancer Care Bundle. Designed for multiple cancer and treatment-related symptoms, our Cancer Care Bundle features 3 of our most popular Delta-9 THC products: our Guided Comfort precision-dosed oral tincture, a 4-pack of Guided Appetite Boost beverage shots and our Guided Rapid Relief Inhaler.
Most importantly, every EO product comes with free clinician-led guidance via phone or email. Whenever you have questions about how you can put cannabis to work most safely and effectively, the EO team will be there to guide you.
The content on this page is for informational purposes. Do not attempt to self-diagnose or prescribe treatment based on the information provided. Always consult a physician before deciding on the treatment of a medical condition.
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Navigating a cancer diagnosis is one of the most difficult life challenges a person can face. Two-time cancer survivor and EO spokesperson Ethan Zohn says, “cancer is a disease that touches every part of you as a human being: mental, physical, social, spiritual. You’re always just looking for ways to make yourself feel better.”
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