A hypnic jerk is an abrupt. involuntary. nonrepetitive contraction of muscles of the body that occurs during the onset of sleep in stage 1 of nonrapid eye movement sleep. Various physiological and stressful stimuli can precipitate hypnic jerks with no further neurological sequelae. https://www.chiggate.com/loving-earth-jilungin-dreaming-tea-30g-cheap/