What are the side effects of Medical Cannabis?

Users most often report reduced rem, lack of, less mentally, memory issues, motivation loss. Side effects came up 6 times across 6 reports.

Medical Cannabis side effects

Q: Is Medical Cannabis safe?

User reports can't establish safety. PubMed lists 94 meta-analyses and 24 randomized trials. Talk to a doctor or pharmacist, especially if you take other medication.

Across 6 first-hand reports, people mentioned a side effect 6 times (about 100 per 100 reports). The most common: reduced rem, lack of, less mentally. User reports show what people notice — they can't tell you whether Medical Cannabis is safe for you.

Reported side effects

reduced rem1

lack of1

less mentally1

memory issues1

motivation loss1

cognitive impairment1

In their own words

“I'm very aware that the THC in cannabis can reduce REM sleep, and I’ve definitely noticed a lack of dreaming and sometimes waking up feeling less mentally refreshed.”

MixedRead the discussion ↗

“It also has had a strong mood stabilizing effect on my depression. However since starting it, I have had been having problems with drive and motivation... cognitive issues at this point (trouble following plots in a movie, coming to conclusions)”

MixedRead the discussion ↗

Is Medical Cannabis safe? What the research covers

AResearch: Strong94 meta-analyses · 24 randomized trials on PubMed

BMJ · 2021

Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials

Conclusion: Moderate to high certainty evidence shows that non-inhaled medical cannabis or cannabinoids results in a small to very small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared with placebo. The accompanying BMJ Rapid Recommendation provides contextualised guidance based on this body of evidence. SYSTEMATIC REVIEW REGISTRATION: https://osf.io/3pwn2.

Heart · 2025

Cardiovascular risk associated with the use of cannabis and cannabinoids: a systematic review and meta-analysis

Conclusion: This systematic review and meta-analysis uses an original approach centred on real-world data. The findings reveal positive associations between cannabis use and MACE. These findings should encourage investigating cannabis use in all patients presenting with serious cardiovascular disorders.