This claim is false. While overdosing on marijuana is not necessarily life-threatening, it is possible. This can lead to extreme anxiety, psychotic reactions, paranoia, a fast heart rate, and even a heart attack or seizure. Side effects may last 1 to 3 hours when inhaling the drug, or several hours if consumed through food or drink. 
Marijuana can become dangerous when combined with other drugs or alcohol. The interaction between alcohol and marijuana increases the level of THC in the blood, which can intensify these symptoms and lead to unpredictable reactions. To reduce the risk of an overdose or adverse effects, it's important to understand and avoid potentially harmful interactions between marijuana, alcohol, and other substances.