Does topical capsaicin cream work for cannabinoid hyperemesis syndrome? | Research

The takeaway

A systematic review and meta-analysis of 7 studies with 106 patients found that topical capsaicin provided symptom relief for cannabinoid hyperemesis syndrome with an average time to resolution of about 325 minutes.

Emergency clinicians treating CHS, cannabis users experiencing cyclic vomiting, and anyone interested in novel treatments for this increasingly common condition.

106 patients across 7 studies

What the researchers found

Across 7 included studies (106 patients), topical capsaicin appeared effective for CHS symptom relief. Mean time to symptom resolution was 325 minutes (95% CI 234-787), and ED length of stay averaged 379 minutes (95% CI 10-747). Heterogeneity was acceptable (I-square 44%, Q-statistic p=0.1).

Why it matters

Cannabinoid hyperemesis syndrome is increasingly recognized in emergency departments, and standard treatments (antiemetics, antipsychotics, benzodiazepines) are not always effective. Topical capsaicin is a low-cost, low-risk alternative that works through a different mechanism (TRPV1 agonism).

The numbers in context

328 studies screened; 7 included; 106 total patients; mean time to symptom resolution: 325 minutes; mean ED length of stay: 379 minutes; I-square: 44%

How the study worked

Systematic review and meta-analysis searching PubMed, SCOPUS, and Google Scholar through October 2020. From 328 initial studies, 7 met inclusion criteria. Evaluated hospital admission rates, time to symptom relief, and ED length of stay.

What this study cannot tell us

Only 7 studies with 106 total patients. No randomized controlled trials included. Wide confidence intervals reflect uncertainty. Heterogeneous study designs and capsaicin application protocols.

How to read the evidence

Systematic review and meta-analysis, but limited to small, non-randomized studies with wide confidence intervals.

When this study was published

Published in 2021; more rigorous trials of capsaicin for CHS are needed.

The bigger picture

The mechanism makes biological sense: capsaicin activates TRPV1 receptors, which interact with the endocannabinoid system. This receptor-level explanation supports the clinical observations and suggests a biologically plausible treatment pathway for CHS.

Questions still open

What is the optimal capsaicin concentration and application area for CHS? Could capsaicin be used as a first-line treatment instead of traditional antiemetics? Why does capsaicin work for CHS when standard antiemetics often fail?

Common questions

What is capsaicin and how does it help CHS?

Capsaicin is the compound that makes chili peppers hot. Applied topically (as a cream), it activates TRPV1 receptors that interact with the endocannabinoid system. This appears to relieve the severe nausea and vomiting of CHS.

How quickly does capsaicin work for CHS?

In the pooled analysis, mean time to symptom resolution was about 325 minutes (approximately 5.4 hours). However, confidence intervals were wide, and some patients likely responded faster while others took longer.

Read the original research

Topical capsaicin for the treatment of cannabinoid hyperemesis syndrome, a systematic review and meta-analysis.

The American journal of emergency medicine, 43, 35-40

View on PubMed ↗Publisher’s paper ↗

Citation

Pourmand, Ali; Esmailian, Gabriel; Mazer-Amirshahi, Maryann; Lee-Park, Owen; Tran, Quincy K. (2021). Topical capsaicin for the treatment of cannabinoid hyperemesis syndrome, a systematic review and meta-analysis.. The American journal of emergency medicine, 43, 35-40. https://doi.org/10.1016/j.ajem.2021.01.004