Manchester trio, Marconi Union, worked with sound therapists to create the soothing tune called Weightless, which also slows breathing and reduces brain activity.
The song features guitar, piano and electronic samples of natural soundscapes.
Scientists played the 8-minute song to 40 women and found it to be more effective at helping them relax than songs by Enya, Mozart and Coldplay.
The study - commissioned by bubble bath and shower gel firm Radox Spa - found the song was even more relaxing than a massage, walk or cup of tea.
Specialists have warned not to listen to it while driving.
Is this the most relaxing song ever? What do you think?