Nitric oxide (NO) is a key signalling molecule used in cellular communication, coordination, and homeostasis across organisms from bacteria to humans. Through oxidation-reduction cycling, NO rapidly initiates biological signalling by diffusing across lipid membranes, enabling intercellular communication during trigger events such as growth, regulation, or immune response. In terms of pharmacology, NO has potent vasodilator properties, used primarily in the treatment of cardiovascular diseases, shock, pulmonary hypertension, and similar pathologies. Additionally, NO is rapidly gaining attention as an important neuromodulator involved in learning and memory.

See also: peak experience, flow genome project, altered state, non-ordinary state