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Content reviewed by
Dr. Lewis JasseyMedical Director - Pediatric Medicine
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Experiencing a “green out” or “white out” can be scary, especially for new cannabis users. This term refers to the unpleasant sensations a person may feel after ingesting too much cannabis. Symptoms such as nausea, anxiety, and paranoia can occur, similar to the effects of weed shakes. Additionally, you may vomit, feel dizzy, or sweat excessively.
Although a green-out can be alarming, leading to increased panic or anxiety, it’s crucial to remember that this state is temporary and manageable. Consuming potent cannabis edibles (like brownies) or mixing cannabis with alcohol are common causes of greening out. The important thing to know is that there’s no need to worry: these symptoms typically fade within minutes to hours.
Lying down can often help speed up recovery, too.
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Is Greening Out Overdosing?
Greening out is essentially a tetrahydrocannabinol (THC) overdose. THC is the psychoactive cannabinoid in cannabis, which is responsible for the altered state of consciousness, feelings of euphoria, relaxation, and heightened senses often associated with cannabis use.
It is hard to imagine THC could be responsible for the adverse effects associated with greening out, in part because of the role of THC in medical marijuana use cases.
High cannabidiol (CBD) and cannabigerol (CBG) may also cause nausea. The anti-emetic (anti-nausea) properties of cannabis are usually experienced by taking your time with cannabis, dosing carefully, and slowly building tolerance to THC.
So what happens in our body during THC overdose that causes this potentially beneficial compound to affect our bodies negatively?
Our bodies possess an endocannabinoid system (ECS) that includes cannabinoids such as anandamide and CB1 and CB2 receptors that bind with cannabinoids in a lock-and-key system that helps improve physiological functions throughout the body.
Some biological systems regulated by the endocannabinoid system include brain function, blood sugar levels, reproduction, the nervous system, and metabolism.
Since THC is a cannabinoid, it can bind with CB1 receptors in the brain and affect serotonin levels. This interaction is what makes THC able to alter the state of consciousness.
Serotonin is usually known as the happiness hormone. However, that is not true when the compound is produced in large quantities. Greening out occurs when THC is taken in large amounts, leading to overstimulation of the brain and prompting the production of serotonin in large quantities.
Serotonin overdose may lead to a severe medical condition known as serotonin syndrome. Symptoms of this condition are similar to the greening-out phenomenon and include confusion, vomiting, hallucinations, increased heart rate, nausea, and vomiting. However, suffering from serotonin syndrome due to cannabis use alone is highly improbable.
Cannabinoid Hyperemesis Syndrome (CHS) is another medical condition that can cause a green out. CHS usually results from long-term cannabis use. In common with greening-out symptoms, patients may experience abdominal pain, recurring nausea, and dehydration. Again, CHS is a relatively rare occurrence, so you are more likely to suffer from a green out than CHS. CHS is also a recurring condition where symptoms occur when cannabis is used, so a single episode of greening out should not necessarily be construed as CHS.
Greening out is more common in people who consume alcohol before using cannabis and in new cannabis users because their systems have not yet built up a tolerance for cannabis. Edibles may also increase the chances of experiencing a green out as eating decarboxylated cannabis is a more potent administration route.
You may experience a green out by inhaling too much cannabis too quickly. However, inhalation and tinctures make it simpler to go slow and low to reduce the chances of a negative side effect.
Alcohol in your system will increase the absorption of THC, thus aggravating greening-out symptoms.
What Causes a Green Out?
Although greening out typically occurs in new cannabis users, it’s fairly uncommon.
It’s important to remember that the method of consuming cannabis doesn’t influence whether or not someone will green out. You could experience greening out from dabbing, smoking, or eating cannabis if the THC levels are high enough.
It’s worth mentioning that when you eat cannabis, the effects take longer to set in, but they also last longer. This means that greening out from cannabis edibles is possible, and the green-out effect could potentially last longer because it takes more time for the effects to kick in.
On the other hand, vaping, smoking, or dabbing cannabis allows for faster absorption of the substance, leading to a quicker onset of effects.
How to Tell a Green Out Is Happening
Symptoms of greening out include:
- Nausea and vomiting
- Increased heart rate
- Paranoia and anxiety
- Limb heaviness (lack of mobility)
- Dizziness and lack of focus
- Chills or sweats
- Breathing problems
- Hallucination (rare)
How Long It Lasts
The unpleasant side effects, or “greening out,” typically lasts for the duration of your high. This can vary greatly and depends on several factors, such as the amount of cannabis consumed, the THC level in the product, your body weight, tolerance level, whether you had a meal prior, and your metabolism.
A cannabis high can last anywhere from one to 24 hours. In general, the effects last longer for those who consume larger amounts of THC, particularly through edibles. Here’s a quick overview of how long cannabis effects might last based on the method of consumption:
Potential Risks and Side Effects
Even though greening out likely won’t lead to long-term health effects, users with an underlying health condition should beware.
If you have a pre-existing heart condition, avoid THC. The compound may lead to thinning of blood vessels, leading to an increased heart rate and a drop in blood pressure, causing a potentially lethal medical emergency.
THC may also interact negatively with other prescription medications, so always talk to your medical care provider about drug interactions before consuming THC and/or CBD.
Another side effect common with greening out is hyperventilation. As your heart rate increases, thanks to high doses of THC, your body struggles to provide enough oxygen, making breathing hard.
Tips for Handling a Green Out
Removing yourself from an overstimulating environment is always best if you’re greening out: Find a quiet place to lie down and ride the wave out.
If you experience panic and feel out of touch with reality, a friend can help you get through this situation. A friendly face can reassure you that things will soon return to normal.
Some users have reported that sugary drinks have helped them manage greening out.
If you prefer a science-backed solution, try CBD oil — it may subdue the paranoia and anxiety caused by overconsuming THC.
Terpenes such as beta-caryophyllene are found in black pepper, rosemary, and cloves, and limonene, located in lemons, oranges, and grapefruit, can also soothe psychoactivity. Both of these terpenes can also be found in cannabis.
For more information, check out our tips on counteracting a negative cannabis experience.
Pro Tip: Limonene is highly concentrated in the outer rinds of oranges, lime, and lemon, not in the inner fruit.
The Bottom Line
Prevention is better than a cure, which also holds for greening out.
Though greening out doesn’t lead to health risks unless you have a pre-existing condition, it can cause those who have experienced it to associate cannabis with adverse effects. This can be problematic if you take marijuana to manage a medical condition.
The best way to prevent greening out is to build up your tolerance regarding THC dosage. Start with small doses and observe how your body reacts. Eventually, this will give you an idea of what you can handle.
Another way to avoid greening out is to be careful with edibles. These take longer to take effect, so you might keep consuming, unaware that your THC dosage increases with each bite. CBD-rich edibles may be less likely to cause a green out, but it is still possible for some people to feel nauseous after consuming too much CBD.
Edibles from legal sources generally list THC amounts and the recommended dose per session. When learning your tolerances and limits, stick with these guides as much as possible, and speak with a doctor to further understand your body’s cannabis limitations.
Frequently Asked Questions
What should you do when you’re greening out?
A green out will usually pass with time. Try to find a pleasant, calm environment and sleep it off. If you’re experiencing paranoia and anxiety, find something to distract you, like music or TV. Ultimately you want to stay hydrated, calm, and comfortable.