Background:Rhodiola rosea roots and rhizomes are a herbal medicine for temporary relief of stress symptoms such as fatigue and sensed weakness. A daily dosage of 400 mg is recommended. Methods: A dry ethanolic extract of R. rosea (WS® 1375) was studied in 100 subjects with prolonged or chronic fatigue symptoms. In an uncontrolled, open-label multicenter clinical trial, the subjects were administered 2 × 200 mg WS® 1375 over 8 weeks. Outcome measures were scales and tests related to fatigue. They were evaluated in an exploratory data analysis to generate hypotheses regarding efficacy. The pilot character of the trial is marked by its broad focus on subjects suffering from fatigue in general and by its comparatively long duration. Results: The greatest change was observed after 1 week of treatment. The fatigue symptoms continued to decline further, with statistically significant improvement at week 8. The safety assessments of WS® 1375 during the trial proved to be favorable, with most adverse events being of mild intensity and not related to the study drug. Conclusions: The results indicate that 2 × 200 mg WS® 1375 may be an effective treatment in subjects suffering from prolonged or chronic fatigue. The safety and tolerability of WS® 1375 also presented a favorable profile.

Background Silexan is a lavender essential oil with established anxiolytic and calming efficacy. Here we asked whether there is a potential for abuse in human patients. Methods We carried out a phase I abuse liability single-center, double-blind, 5-way crossover study in healthy users of recreational central nervous system depressants. They received single oral doses of 80 mg (therapeutic dose) and 640 mg Silexan, 2 mg and 4 mg lorazepam (active control) and placebo in randomized order, with 4- to 14-day washout periods between treatments. Pharmacodynamic measures included validated visual analogue scales assessing positive, negative, and sedative drug effects and balance of effects; a short form of the Addiction Research Center Inventory; and a drug similarity assessment. The primary outcome measure was the individual maximum value on the drug liking visual analogue scale during 24 hours post-dose. Results Forty participants were randomized and 34 were evaluable for pharmacodynamic outcomes. In intraindividual head-to-head comparisons of the drug liking visual analogue scale maximum value, both doses of Silexan were rated similar to placebo whereas differences were observed between Silexan and lorazepam and between placebo and lorazepam (P < .001). These data were supported by all secondary measures of positive drug effects and of balance of effects. Differences between placebo and both doses of Silexan were always negligible in magnitude. Moreover, Silexan showed no sedative effects and was not perceived to be similar to commonly used drugs that participants had used in the past. Conclusions Silexan did not exhibit any abuse potential in a standard abuse potential detection screen study and is unlikely to be recreationally abused.

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