What is an indicator of marijuana use?

Bloodshot eyes are a well-documented indicator of marijuana use due to the active ingredient in marijuana, tetrahydrocannabinol (THC), which causes blood vessels to expand, leading to the reddening of the eyes. This physical reaction is one of the most recognizable signs associated with marijuana consumption and can easily be observed by others.

On the other hand, increased alertness is typically associated with stimulant use rather than marijuana, which can have a more sedative effect. Frequent sniffing might suggest nasal irritation or allergies rather than specifically indicating marijuana use, as it can occur for a variety of reasons unrelated to drug consumption. Lastly, paranoia can be a symptom experienced by some individuals after using marijuana, especially in larger doses, but it is not as clear or universally recognized as a direct indicator as bloodshot eyes.