Marijuana

A NYPD officer recently said she failed a marijuana drug test because officials tested hair from a weave she wore. But how does marijuana get into hair, and how long does it stay there?

Many hope that marijuana will help their insomnia. A sleep psychologist examines the evidence.

Marijuana with relatively high levels of a compound called cannabidiol may be less risky to smoke over the long term, because this ingredient may counteract some of the drug's harmful effects.

Marijuana's popularity among American adults is on the rise — and use of the recreational drug is expected to continue to increase, according to several surveys.

Smoking pot is often considered safer than smoking cigarettes, but a new study suggests that marijuana use may increase a person's risk of death from high blood pressure.

What happens when you combine caffeine and marijuana?

The federal government outlaws marijuana, but many states are legalizing it. Coupled with the growing number of cannabis-related patents, the potential for court battles is dizzying.

Officials in Canada are releasing guidelines for how people can lower the health risks associated with using marijuana

In Washington and Colorado, legalizing marijuana hasn't seemed to increase fatal car crashes, new research shows.

Rolling back protections from federal interference in state legalization laws could worsen the opioid overdose crisis.