The present invention relates to the use of adenosine receptor modulators to affect the circadian rhythm, in particular, to the use of such modulators for the treatment of circadian rhythm disorders. In particular, the invention relates to a com position com prising at least one selective adenosine receptor modulator, wherein said composition modulates two or three, but not al l of adenosine receptor subtypes A1, A2A, A2B and/or A3 for use in the treatment of circadian rhythm disorders or for modulating a biological clock.
