The study was published April 8, 2021 in the Journal of Clinical Gastroenterology, and followed 886 patients. It found that within 1 hour, 96.4% reported a significant reduction in nausea symptom intensity, and even within 5 minutes, there was a significant reduction in their symptoms.
"Flower and concentrates yielded the strongest, yet similar results; products labeled as Cannabis indica underperformed those labeled as Cannabis sativa or hybrid; and joints were associated with greater symptom relief than pipes or vaporizers. In sessions using flower, higher tetrahydrocannabinol (THC) and lower cannabidiol (CBD) were generally associated with greater symptom relief (eg, within 5 min)."
According to this study, the most effective product is high THC, low CBD Sativa or Hybrid flower in the form of a joint, over a pipe or vaporizer. For some reason, products labeled Indica were not as effective. We expect this is due to the differences in dominant terpenes that are normally dominant in each cultivar. Indica is generally known for high Myrcene content, while Sativa is generally known for a lower Myrcene content, and higher Pinene and Terpinolene content.
The link to the abstract is here.