THC Overdose: Causes, Symptoms, & Prevention

An overdose of THC, also known as THC poisoning or acute intoxication, refers to the adverse and sometimes dangerous effects experienced after overconsumption of THC. These effects may be felt immediately or after minutes or hours. 

THC overconsumption is usually not life-threatening and will subside with time. However, there are things to be aware of and steps to take to avoid overdose.

Common Causes of THC Overdose

A THC overdose occurs when you consume more than recommended, either accidentally or on purpose. An overdose often happens when you ingest another dose of THC before the full effects of the previous intake are fully felt, or if you combine it with other drugs, such as alcohol.

When inhaled, THC is absorbed straight into the bloodstream via the lungs, causing the effects to be felt quickly, within five to thirty minutes of consumption (page 3 of the PDF).THC consumed via inhalation tends not to be as much of a risk for overdose because of this.

THC in the form of edibles is much more likely to cause an overdose, as it is absorbed into the bloodstream after being digested. Effects are felt much more slowly, typically thirty minutes to four hours after consumption. 

This leads to the risk of another dose being consumed before the effects are felt or fully known.Check out our article on How to Recover From Edibles if you've already overdosed.

Pro tip: Knowing the correct THC dose for your condition and biology is important. Doctors who specialize in medical cannabis will provide tailored guidance on how to take THC safely at your initial MMJ appointment or when you go to renew your MMJ card.

Signs of Marijuana Overdose in Adults, Children, & Pets

Marijuana overdose symptoms are similar in adults and children, though the usual signs of being high are a concern when noticed in children.

Adults

The signs of THC overdose in adults range from mild to severe, and may include some or all of the following symptoms:

• Extreme anxiety, paranoia, panic attacks

• Fast heart rate or blood pressure

• Hallucinations

• Nausea or vomiting

More severe symptoms:

• Psychosis

• Uncontrollable shaking or seizures

• Pale or clammy skin

• Loss of consciousness

• Respiratory depression
  

Children

THC overdose symptoms in children are the same as for adults above, as well as the following symptoms that adults may experience as part of a normal high, including:

• Slurred speech

• Lethargy

• Dizziness or poor coordination

• Changes in behavior or mood
  

Pets

The most common signs of THC toxicity in pets are:

• Urinary incontinence

• Disorientation and difficulty walking

• Lethargy

• Decreased heart rate
  

What to do in the Case of a THC Overdose

Responding to a THC overdose is different in adults, children, and pets.

Adults

At-home management is recommended for milder symptoms. Stay hydrated, eat healthy snacks, rest, do an enjoyable activity until the symptoms pass, go for a walk, and eat black peppercorns.

If symptoms are severe, call 9-1-1 or go to your nearest emergency department.

Children

Children must only consume THC as medically prescribed. If taken otherwise, seek medical attention, go to the nearest emergency room, or call the free Poison Control Center hotline at 1-800-222-1222 (U.S. only).

Pets

For pets, a trip to the vet is always recommended. The vet may administer intravenous fluids, anti-seizure medications, or other treatments as required. There is no need to avoid the vet out of embarrassment. It's better to make sure your pet is looked after and recovers well.

Prevention

The best way to prevent THC overdose is to wait until the full effects are felt before consuming more. 

• If inhaling your cannabis, it is probably best to wait for half an hour before taking another hit, to properly ascertain how high you are first. 

• If ingesting edibles, start with a small amount and wait at least two hours before consuming any more. If you're taking edibles that come with instructions, please follow the instructions.
  

Prevention for Children & Pets

To prevent cannabis consumption and overdose in children or pets, be careful to store THC products where a small explorer can't get to them. Some suggestions are in locked cabinets or high cupboards that can't be reached. 

When throwing out THC products or old edibles, it's best to dispose of them in a way that children and pets can't get to them, such as inside a container and then buried deep in the trash can, or inside a tied-up plastic bag. Local dispensaries generally also offer cannabis product disposal.

Risks

Along with medical benefits, there can be unwanted side effects and risks to overconsuming cannabis products, especially where substance abuse is involved. These vary wildly, including:

• Addiction or dependence on cannabis

• Inhalation-related health effects, such as sore throat, asthma, coughing, and cancer, if mixed with tobacco

• Mental effects, such as reduced cognitive functioning and psychotic reactions

• Interactions with alcohol and other drugs, even if prescribed

• Affects everyday tasks such as driving or operating heavy machinery, with increased risk of motor vehicle crashes (See laws in your local area.)

• As with all drug use, accidental death is possible. This is due to the risk of overdose, interaction with other substances or medications, and accidents occurring from performing risky tasks when not at full cognitive capacity, such as driving. 
  

The best way to avoid all of these problems while maximizing the benefits is to consume cannabis under medical supervision.

FAQ

What if I Get High and Drink Alcohol?

Combining weed with alcohol or other drugs typically increases the effects of both or causes your reactions to them to become unpredictable. It's best to avoid mixing substances.

What if I Take Other Medications or Have Comorbidities?

It’s always best to discuss with your marijuana doctor if you have any other medical issues or take other medicines. For the late-night panic when you can’t speak with your doctor, check drug interactions online to see if your medications are okay to have with cannabis. 

If you have other medical issues, such as heart problems or certain mental health concerns, THC consumption may exacerbate the issues to unsafe levels, so a discussion with your doctor is best.

What if My Dog Eats Weed Brownies or Cookies?

If your dog eats THC-containing brownies or cookies, these may contain chocolate, which is also toxic to dogs. Be aware of symptoms of chocolate consumption in dogs, such as vomiting, diarrhea, excessive thirst and urination, restlessness, panting, and abdominal pain. Look for these symptoms when monitoring your dog at home, and relay them to the vet.

Dose THC Responsibly

The best way to avoid a marijuana overdose is to wait until the full effects are felt before consuming more. If it’s too late for that, keep an eye on your symptoms and manage them at home. 

Seek medical assistance for more severe symptoms, or for THC overdose symptoms in children or pets. The risk increases when cannabis is mixed with other drugs or medications.

Know your limits and work with your MMJ doctor for optimal dosing and symptom relief.