Experimental Factor Ontology identifier EFO_0009848 (antiemetic effect) is an antiemetic effect involves suppression of nausea and vomiting. Emesis is a complex process coordinated by a central emesis center located in the lateral reticular formation of the mid-brainstem. Inhibition of certain neurotransmitters (e.g., 5-HT) or their receptors located in this region inhibits emesis.