Greening Out: Understanding the Effects of Too Much THC

Alternaleaf Team
Written by
Alternaleaf Team
Dec 17, 2022
Last updated:
Dec 15, 2023

Tetrahydrocannabinol (THC) is a medical compound found in cannabis. It’s deemed safe by the TGA, and there is a lot of scientific support for its use in medicine. But, like all medicines, taking too much can have the opposite effects of what’s intended. In the world of cannabis, this is called greening out.

Most patients only report positive effects from THC—pain relief, positive mood changes, and relaxation. But what happens when you ingest too much marijuana and feel sick?

Let's examine one of the rare but still-possible side effects of too much THC, plus how you can avoid it by starting low and going slow — and working with a doctor.

What Is Greening Out?

If this has ever happened to you, chances are you know how greening out feels. It’s uncomfortable and unpleasant, but it is short-lived. Some common effects of too much THC include heightened anxiety and an elevated heart rate.

According to a study in the Handbook of Experimental Psychology, others may experience mild hallucinations, sweating, lower blood pressure, and nausea. Onset can be slow or more sudden, with the unpleasant feelings lingering for up to a few hours.

Greening out is rare but may occur when someone accidentally takes too much cannabis oil, flower, or other forms. Perhaps they are inexperienced with it or didn’t understand the correct dose.

How Does Greening Out Happen?

The mechanism behind greening out is the endocannabinoid system, which regulates many of your body’s processes, including sleep and waking, digestion, immunity, and more. This network consists of chemicals and receptors that work in tandem to keep you functioning.

When you ingest THC, the substance binds to the CB1 receptors in your brain. However, if you take too much of this cannabinoid, it can overwhelm these receptors.

The result is that these overworked receptors can no longer do their job correctly. That, in turn, throws your body out of balance, causing you to feel the unpleasant effects. These effects pass quickly as your body metabolises the THC, and the receptors return to homeostasis.

What Happens if You Accidentally Take Too Much THC?

If you find yourself greening out or taking care of someone who is, don’t panic. Remember, the majority of the time, these effects are mild and short-lived. A few strategies to get through moments of discomfort include:

  • Get as comfortable as possible
  • Move to a quiet and calming space
  • Lower the lights and put on soothing music
  • Drink water
  • Breathe deeply

If you have consumed other intoxicating substances (alcohol, illicit drugs, prescriptions), THC's effects may intensify. If you are worried about the effects you’re experiencing, you can always call 000.

How To Avoid Greening Out

green leaf, with veins, close up macro photo
Working with an experienced medical cannabis doctor can reduce the risk of greening out.

Although cannabis has been labelled a relatively safe substance by the TGA and other regulatory bodies, and there are no reported deaths from a cannabis overdose, greening out is not a pleasant experience.

Fortunately, for medical cannabis patients working with a doctor, this is not only a rare experience but an entirely preventable one.

Your doctor will personalise a treatment plan with specific dosing instructions. It is always wise to take the “low and slow” approach to marijuana consumption, starting with a low dose and working up to a larger one as you become familiar with the effects.

The good news is that thanks to medical cannabis in Australia going legal, you will always know precisely what’s in your prescription. And with the guidance of a doctor, you’ll always know exactly how much to take.

The Safest Cannabis Available

Greening out can feel overwhelming, sometimes even discouraging people from using cannabis at all. However, with the right advice and the best possible products, you can safely consume medical cannabis and enjoy its potential  benefits — without the risk of overdoing it.

If you think that medical cannabis may be able to help with your condition, start by setting up a consultation with a doctor at a medical cannabis clinic or your local GP.

There are a number of risks associated with the use of medical cannabis and your doctor will explain these to you before issuing a prescription. Medical cannabis affects everyone differently and may not help with your chronic condition.

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