Taking a Break from Cannabis: What to Expect

Not everyone. The often-quoted figure of about half comes from studies that include people already in care. In samples of the general population it is closer to one in six, and among US adults using three or more times a week it was about one in eight.

• General-population samples: 17%. People in outpatient care: 54%. Inpatient care: 87%
• It is more likely with daily use, with tobacco use, and with other substance use
• More severe dependence beforehand predicts a harder withdrawal
• Women report stronger withdrawal than men, including more nausea and stomach pain

Symptoms usually begin one to three days after the last use, peak in the first week, and ease within about two weeks. In people who used heavily, some symptoms last three weeks or more.

• Days 1–3: symptoms begin, usually within 24 to 48 hours
• Days 2–6: the peak, typically with poor sleep, irritability, low appetite and shakiness
• By about two weeks: most symptoms have eased
• Weeks 3–4 and beyond: sleep can stay unsettled after everything else has settled
• In a study of adolescents, sleep was worst in week 1, improved in week 2 and was back to its starting level by week 4

The common symptoms are emotional: anxiety, irritability, anger, disturbed sleep and vivid dreams, low mood and loss of appetite. Physical symptoms such as chills, headaches, tension, sweating and stomach pain are less common.

• Vivid or strange dreams are the most characteristic sign, and most people do not find them the hardest part
• Trouble getting to sleep and sudden anger are rated as both intense and distressing
• Among people with withdrawal, about three in four report anxiety and about two in three report sleep difficulty
• These symptoms overlap with anxiety and depression, so it helps to tell a clinician you have recently stopped

The standard advice is clinical practice with little research behind it. That is worth knowing: it is reasonable, widely used, and not proven.

• Know the timeline, so the worst days do not come as a surprise
• Keep a regular sleep routine; sleep is the symptom most likely to linger
• Move your body; one small study without a comparison group found less craving and less use during a two-week exercise program
• Eat and drink regularly even when you are not hungry
• Have a plan for cravings before they arrive

No length is backed by research. The figures people pass around, from two days to four weeks, are custom. What studies do show is how the body responds over time.

• Withdrawal mostly passes within two weeks
• In small brain-imaging studies, cannabinoid receptors began recovering within two days and were back to normal after about four weeks
• That is a finding on a scan; no study links a number of days to how cannabis will feel afterwards
• A structured 21-day guide has been studied without a comparison group: people who used it a lot were more likely to finish the break, 84% against 57%

One study followed 170 young adults for six months. Those who took a break specifically to lower their tolerance had more hazardous use afterwards, and the length of the break made no difference. Longer breaks taken for other reasons were linked with using less.

• This is one observational study; it shows a pattern, not a cause
• The authors' reading is that taking a tolerance break may be a marker of higher risk, not the cause of it
• If the aim of a break is to get more effect from the same amount, the guide on where you stand may be the more useful place to start

Several things improve, some of them quickly.

• In a trial of 16-to-25-year-olds, verbal learning improved within the first week of stopping; attention did not change
• Across 69 studies of young people, measured thinking differences were small and largely gone after three days without cannabis
• Sleep returned to its starting level by week 4 in adolescents
• In adults getting help, using less went with better anxiety, mood and sleep

For most people withdrawal is unpleasant and not dangerous. For some, stopping should be planned with a clinician.

• If you have ever had psychosis, or have another mental health condition, talk to a clinician before a break
• In reported cases, daily users who stopped abruptly developed acute psychosis; how rare this is has not been measured
• If you use other substances as well, supervised withdrawal may be the lower-risk route
• Get urgent help if signs of psychosis appear, such as paranoia or seeing or hearing things that are not there, whether you are using or have just stopped
• If you have thoughts of suicide, call or text 988 in the US. In an emergency, call 911