Circadian rhythm plays an important role in human physiology. Its abnormal functioning results, among others, in jet lag disorder (JLD- Jet Lag Disorder), which is a discomfort experienced by people travelling between time zones, as well as being the cause for metabolic diseases in people working shifts. Recent studies have shown the role of vasopressin V1a and V1b suprachiasmatic nucleus (SCN- surachiasmatic nucleus) of the hypothalamus in the regulation of circadian rhythms. Mice genetically lacking receptors are resistant to disturbances of circadian rhythm, and are characterized by an almost immediate adjustment to the new rhythm. A similar effect is achieved by pharmacologically blocking V1a and V1b receptors. Research gives hope of overcoming this disorder to travellers who traverse time zones at high speed, as well as creating the possibility of adaptation to shift work without provoking any negative consequences over one´s health.