Cannabis has been used for ages already as a sleep aid. Cannabis has sedative and relaxing benefits where it makes falling asleep easier. Studies state that cannabis shortens the time it takes people to fall asleep. It shortens the time to fall asleep with 30 minutes for those with sleep problems. Cannabis also lengthens the time spent in deep, slow-wave sleep. It also appears to shorten the time spent in REM sleep, likely due to THC.