Sleep improving effects of a single dose administration of a valerian/hops fluid extract. A double blind, randomized, placebo-controlled sleep-EEG study in a parallel design using the electrohypnogram

Repetitive administration of valerian/hops combinations has been widely used for self-administered therapy of sleep disturbances due to their lack of side effects. Based on the electrohypnogram – derived from a validated computer assisted automatic analysis for depth of sleep – a new approach was started following a single dose administration of verum (n=20) or placebo (n=22) to poor sleepers. Two ml of the liquid extract or placebo were diluted in 50ml water (flavoured with honey) and administered 15 minutes before EEG recording during the medication night following a polysomnographic baseline night. The time spent in sleep (values of the sleep frequency index (SFx) of the electrohypnogram beyond 74% or lower as difference between the baseline nights and the medication nights) was significantly higher for the verum group in comparison to the placebo group (p<0.01). The difference in time spent asleep beyond other lower different depths of sleep (i.e. 68 or 62%) between baseline and medication night was also statistically significant at p<0.01. This new parameter correlated with the difference in quality of sleep between the two consecutive nights as derived from the sleep inventory SF-A sub-score (volunteers subjective evaluation) with r=0.48at p<0.0001. This EEG derived parameter “sleep quantity“ as calculated from the electrohypnogram proved the superiority of the valerian/hops combination over placebo. Thus, the present investigation has shown evidence for a positive effect of a combined valerian/hops fluid extract on EEG derived surrogate parameters of sleep related to the quality and the restful effect of sleep.