Can You Overdose on Weed? The Lethal Dose Math and How to Handle a Bad High

Can you overdose on weed? Not fatally, as far as the record shows: there's no documented death in history caused by a cannabis overdose alone. You can absolutely take too much and feel awful, though, and even as research on cannabis use keeps growing, there still aren't many reports or studies on cannabis overdose in humans. 

When the medical world talks about drugs, each one gets an "LD50" rating. That number tells you the dose at which a drug would kill 50% of the subjects given it, due to toxicity. And according to testimony from a DEA (US Drug Enforcement Administration) administrative law judge in 1988: "Researchers have attempted to determine marijuana's LD-50 rating in test animals, without success. Simply stated, researchers have been unable to give animals enough marijuana to induce death."

After that testimony, in an effort to give marijuana some kind of rating anyway, the estimate researchers landed on was an LD50 ratio of roughly 1:20,000 to 1:40,000. That means a smoker would have to consume 20,000 to 40,000 times the amount of cannabis in a single joint, all at once. In other words, 20,000 to 40,000 joints.

Even the most seasoned dabber would be passed out on the couch long before getting through what basically adds up to 680 kg (about 1,500 lb) of weed.

That said, smoking a lot of weed can make you feel pretty rough. Most cannabis users have been through the unpleasant side of overdoing it and getting way too high. Greening out, as it's affectionately known, can bring on anxiety and paranoia, dizziness and nausea. These effects can hit especially hard when weed is mixed with alcohol or other substances.

Those effects come mainly from THC, the compound that makes cannabis intoxicating. Over the last few decades, THC levels in cannabis have steadily climbed. These days it's not unusual to find strains testing above 20% THC, enough to knock even an experienced smoker on their butt.

You can also buy concentrates like wax or shatter with THC levels above 90%. Products that strong make it easier than ever to green out, even if you're a regular. 

Edibles are another way to end up feeling lousy. When you smoke weed, the high can peak within about 30 minutes. But when you eat cannabis, you have to wait a lot longer to feel anything.

That's why edibles can take 2 to 4 hours to reach their full effect. It's a classic rookie mistake to get impatient after eating an edible and decide it isn't working. So you eat more.

If you feel like you overdid it, or hit a strain that's way too strong and you're not feeling good, these tips can help:

- Stay somewhere calm where you feel safe, and focus on your breathing.  

- Get someone you trust to keep you company.

- A little sugar may help with the drop in blood pressure that overdoing edibles can cause. 

- Some research suggests that taking CBD in these situations can help, since this cannabinoid may tone down THC's effects. A capsule or a dose of pure CBD extract will do.

- Drink water.

Most important of all: tell someone you're not feeling well. Don't be embarrassed, ask for help, and above all remember that you're not going to die from this, and sooner or later the bad feeling will pass. That said, if symptoms are severe or won't let up, if there's chest pain, fainting or trouble breathing, or if a child or a pet got into the weed, get medical help right away.