It's been compared to alcohol and tobacco, but research into marijuana and its long-term health effects is still a bit, well, green.
Some experts say smoking weed can have lethal effects on the body and mind, while others say it's less toxic and addictive than booze and cigarettes and should be legalized nationwide.
While it would take an estimated 240 joints to overdose on marijuana, there are at least five other ways the drug can put your at risk (not counting being crushed by your stash, like this Brazilian trafficker).
Here's a breakdown of what we know and don't know about the health effects of marijuana – a drug that roughly 5.4 million Americans use on an almost-daily basis.
|It Hurts Your Lungs|
Like tobacco, marijuana is usually smoked. And smoke of any kind irritates the lung.
Some studies have equated a single joint to as many as 20 cigarettes in terms of lung damage, causing chronic coughs and predisposing users to dangerous lung infections.
But when it comes to cancer risk, the jury's still out: "It is not yet known whether marijuana smoking contributes to risk for lung cancer," according to the National Center on Drug Abuse.
|It Might Hurt Your Heart|
Smoking weed can raise your blood pressure and double your heart rate – cardiovascular effects that test the old ticker.
Some studies suggest marijuana use can increase your risk of a heart attack, particularly in the first hour after use. But one 15-year study found no such effect. The drug is also linked to cannabis arteritis – an arterial disease that can lead to amputations.
|It Can Baffle Your Brain|
Marijuana can make it harder to remember and learn new things – especially in teens and young adults.
"It disrupts the development of circuits," said Dr. Paula Riggs, a substance abuse expert and professor of psychiatry at the University of Colorado. "The latest study shows that regular use when you're an adolescent is associated with a 6-to-8 point reduction in IQ."
|It Can Crush Your Concentration|
Weed can also interfere with judgment, concentration and coordination, which can have deadly effects on the road. Marijuana use among drivers more than doubles the risk of being in an accident, according to the National Institute on Drug Abuse.
|It Can Mess With Your Mood|
Marijuana use has been linked to depression, anxiety and even suicidal thoughts, according to the National Institute on Drug Abuse. In high doses, the drug can also trigger hallucinations and paranoia and worsen the symptoms of schizophrenia.
|Marijuana Tweet Chat Today at 1 p.m., ET|
Now we'd like your opinion. Join ABC News Health for a tweet chat today at 1 p.m., ET and tell us whether you think marijuana should be legal or laws should stay the same.
The chat will be hosted by our chief health and medical correspondent, Dr. Richard Besser. We'll have marijuana experts from all over the country tweeting with us, as well as physicians, researchers and policy makers.
Joining the chat is easy.
Step 1: Go to Twitter Step 2: Search for the hashtag #abcDRBchat Step 3: Follow the conversation -- or chime in when you've got something to add!
Steven Moyo contributed to this story.