Study register / Risks & Safety / Cannabinoid Hyperemesis

Cannabinoid Hyperemesis

4 curated studies · 4 key studies · mechoulam.de

Note: This area collects studies on possible risks and safety aspects of cannabis. A high rating here means the risk is well evidenced, not that cannabis works therapeutically. This is how we show the evidence in both directions, in balance.

Cannabinoid hyperemesis syndrome is a consequence of chronic cannabis use with recurrent, severe vomiting. According to the available reports, symptoms mostly resolve only with sustained abstinence.

Rating scheme

The letter rates the quality of a study, independently of its type. Every study type can receive any grade: a review can be B or C when it is small or weak, and an RCT can be S. The grade is a synthesis of study design, journal authority and clinical bindingness:

S
Highest evidence, large, methodologically first-rate studies or S3 guidelines
A
Strong evidence, solid, meaningful studies with a clear result
B
Moderate evidence, smaller or methodologically limited studies
C
Weak evidence, preliminary, indirect or contradictory findings
D
Lowest evidence, exploratory hints, single cases or expert opinion

Quality profile per study

To the left of each study there is a profile of four features, it shows the differences within a letter class.

Sample size ★
Number of participants (RCT) or included studies (review).
Blinding
Double-blind, single-blind or open-label.
Effect size
Clear benefit, mixed, no benefit or harm.
Citations / year ★
Age-adjusted citation frequency.

Central risk studies

4
  1. 01
    B
    Treatment of cannabinoid hyperemesis syndrome: A systematic review and treatment algorithm for consultation-liaison psychiatrists.
    Hsu et al. ·2025 ·General hospital psychiatry
    Read
  2. 02
    C
    Cannabis Use Patterns and Blood Profiles in Adolescent Cannabinoid Hyperemesis Syndrome.
    Bloom et al. ·2026 ·Pediatric emergency care
    Read
  3. 03
    D
    Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse.
    Allen et al. ·2004 ·Gut
    Read
  4. 04
    D
    The cannabis hyperemesis syndrome characterized by persistent nausea and vomiting, abdominal pain, and compulsive bathing associated with chronic Cannabis use: a report of eight cases in the United States.
    Soriano-Co et al. ·2010 ·Digestive Diseases and Sciences
    Read

Systematic Reviews and Meta-Analyses

Syntheses of RCT evidence following Cochrane and PRISMA standards.

1
B
Sample size ★★★★★
Blinding —
Effect size Clear benefit
Citations / year ★★★★★
● Key study
Hsu et al. ·2025 ·General hospital psychiatry
4 citations

Treatment of cannabinoid hyperemesis syndrome: A systematic review and treatment algorithm for consultation-liaison psychiatrists.

Design
Systematic Review
Sample
k = 34 Studien
n = 63 Pat.
Key finding

Capsaicin cream, antipsychotics and benzodiazepines showed more effective improvement of CHS symptoms (nausea, hyperemesis, urge for hot showers) compared with commonly used antiemetics such as promethazine, ondansetron and metoclopramide.

Summary

Systematic review on cannabinoid hyperemesis syndrome (CHS) treatment; k=34 articles with n=63 individual cases. Capsaicin cream, antipsychotics and benzodiazepines showed better efficacy for CHS symptoms (nausea, hyperemesis, urge for heat) than conventional antiemetics (promethazine, ondansetron, metoclopramide). Authors propose a treatment algorithm for consultation-liaison psychiatrists.

DOI 10.1016/j.genhosppsych.2025.10.012 ↗

Real-World Evidence and Observational Studies

Data from routine clinical care, registries and mandatory reporting.

3
C
Sample size ★★★★★
Blinding —
Effect size —
Citations / year ★★★★★
● Key study
Bloom et al. ·2026 ·Pediatric emergency care
1 citations

Cannabis Use Patterns and Blood Profiles in Adolescent Cannabinoid Hyperemesis Syndrome.

Design
Kohortenstudie
Sample
n = 10 Pat.
Key finding

Observational study without an intervention group; shows differences in cannabinoid metabolites between symptomatic and asymptomatic time points in adolescents with cannabinoid hyperemesis syndrome.

Summary

Pilot cohort of adolescent cannabis hyperemesis (n=10, screening n=869): 100% met CUDIT-R criteria for cannabis use disorder (n=9) or hazardous use (n=1), all reported withdrawal symptoms on attempted cessation. Significantly lower 11-OH-THC levels during the symptomatic episode [median 0,6 ng/mL, IQR: 0–2,6] vs. asymptomatic follow-up [median 4,2 ng/mL, IQR: 1,2–10,1].

DOI 10.1097/pec.0000000000003495 ↗
D
Sample size ★★★★★
Blinding —
Effect size Clear benefit
Citations / year ★★★★★
● Key study
Allen et al. ·2004 ·Gut
528 citations

Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse.

Design
Fallserie
Sample
n = 9 Pat.
Key finding

Cannabis abstinence led to complete remission of cyclic vomiting disorder in 7 of 9 cases.

Summary

Case series (n=9) with chronic cannabis abuse and cyclic vomiting (cannabinoid hyperemesis syndrome, CHS): cannabis abstinence led to complete symptom remission in 7/9 patients; all 3 rechallenge cases suffered relapse. First description of CHS as a causally cannabis-related clinical syndrome with demonstration of the pathognomonic washing behaviour (9/10 cases including case report).

DOI 10.1136/gut.2003.036350 ↗
D
Sample size ★★★★★
Blinding —
Effect size Mixed
Citations / year ★★★★★
● Key study
Soriano-Co et al. ·2010 ·Digestive Diseases and Sciences
102 citations

The cannabis hyperemesis syndrome characterized by persistent nausea and vomiting, abdominal pain, and compulsive bathing associated with chronic Cannabis use: a report of eight cases in the United States.

Design
Fallserie
Sample
n = 8 Pat.
Key finding

Cannabis abstinence led to remission of cannabis hyperemesis syndrome in the majority of patients, while continued use maintained the symptoms.

Summary

Case series (n=8) in the USA: cannabis hyperemesis syndrome characterised by chronic cannabis use, recurrent vomiting (mean episode every 3,0±1,7 h), compulsive bathing (mean 5,0±2,0 baths/day, 5,0±5,1 h/day) and abdominal pain. Mean interval from start of use to onset of vomiting 19,0±3,7 years; mean 7,1±4,3 emergency department visits. 4/5 patients fully recovered after cannabis cessation; renewed use led to relapse in one patient.

DOI 10.1007/s10620-010-1131-7 ↗