Most cannabis products that you can buy legally list the amount of THC they contain. However, if you’re consuming an edible that isn’t packaged, it’s almost impossible to tell how much THC, the psychoactive ingredient, is in food, drink, or smoking products.
Generally, the likelihood of experiencing uncomfortable effects is higher if you’re a first-time or infrequent cannabis user. So if you’re thinking about partaking in 4/20, the right dosage depends on the person consuming cannabis, with a recommended 2.5 mg to start, and capping it at 40 mg of THC per day.
A 2023 study in the journal Molecules at the Institute of Nutrition at Mahidol University in Thailand suggested that smoking 2 to 3 mg of THC can impair attention, focus, short-term memory, and executive function, such as memory, thinking, and self-control.
More severe symptoms affect people who smoke more than 7.5 mg of THC, such as low blood pressure, panic, anxiety, delirium, jerking movements, and difficulties with balance and speech. The same study suggested that an oral dose of 5 to 20 mg of THC can impair short-term memory and “executive functioning.”
Although eating cannabis, or edibles, doesn’t affect the lungs compared with smoking, accidental overdoses are more likely to happen.
It can take from 30 minutes to two hours for the THC to start to affect the body after eating cannabis products. Since it takes longer for the effects of edibles to begin, people might take more of it, thinking they haven’t consumed enough. The high also lasts longer when eating cannabis-containing foods compared with smoking and can last up to 12 hours before the effects subside.
If you’re planning on eating or drinking cannabis products, make sure to wait for the effects to begin, rather than consuming more. If you do end up smoking or consuming too much, you could experience an overdose or cannabis poisoning.
Symptoms of an overdose and poisoning
Signs of smoking or consuming too much cannabis include:
- extreme confusion
- anxiety
- paranoia
- panic
- fast heart rate
- delusions
- hallucinations
- increased blood pressure
- severe nausea or vomiting
“Any time a person feels like they are having a medical emergency, they should seek care at the nearest emergency facility or call 911,” Dr. Carrie Oubre, a board-certified emergency medicine physician based in San Jose, California, told BuzzFeed News. “However, there are many times that people are not sure whether their symptoms are related to an emergent condition.”
People should seek medical help if cannabis use results in an injury, suicidal thoughts, or if they have underlying medical conditions.
“If you do sustain a significant injury related to any type of accident after using cannabis, you should seek emergency care even if your pain level is not as high as you would expect,” Oubre said. “Cannabis can mask your pain symptoms, and the injury may be worse than you feel it is.”
Since THC can amplify symptoms of psychiatric disorders, such as depression, anxiety, PTSD, ADHD, bipolar disorder, schizophrenia, and psychosis, it’s important to get emergency care in those cases of overconsumption, Oubre said.
Additionally, people who already have medical conditions, such as heart disease, lung disease, or diabetes, should be more aware of any symptoms or effects of overdose.
“If you are a person with chronic illness, and you notice that your symptoms have become worse after using cannabis, you should seek emergent care, especially if these symptoms include chest pain and shortness of breath,” Oubre said.
Here’s what to do