The physiological pattern of growth hormone (GH) secretion, in which the pituitary gland releases GH in discrete pulses rather than continuously. The largest pulse typically occurs during slow-wave sleep, with smaller pulses distributed throughout the day. Between pulses, GH levels are near zero.

Pulsatility is not a quirk of biology—it is functionally essential. Continuous GH exposure produces different tissue responses than pulsatile exposure. This distinction is central to the GH secretagogue drug class: compounds like GHRP-6, GHRH analogs (sermorelin, CJC-1295 no DAC), and ipamorelin are designed to amplify natural GH pulses rather than replace them with continuous stimulation. CJC-1295 with DAC, which maintains elevated GH levels for days due to its albumin-binding modification, deliberately sacrifices pulsatility for convenience—a pharmacological tradeoff with implications that are debated in both clinical and community contexts.