Table 2. Studies Reporting the Effect of Valerian on Sleep-Onset Latency.
| First Author, Year | No. of Participants | Subjective Sleep Latency Outcome | Sleep Latency Result | Statistical Significance |
|---|---|---|---|---|
| Leathwood, 198225 | 128 | No. who went to sleep more rapidly/total No. of participants | Placebo: 29/128 Valerian: 47/128 | Yes P = .01 |
| Kamm-Kohl, 198420 | 80 | No. with improved falling asleep/total No. of participants | Placebo: 10/39 Valerian: 33/39 | Yes P < .001 |
| Farag, 200318* | 25 | Mean No. of minutes to fall asleep (SD) | Placebo: 74.1 min (69) Valerian: 57.4 min (51) Mean decrease: 16.7 min (44.8) | Yes P = .003 |
| Coxeter, 200317 | 21 | Proportion of success (95% CI) | 43% (29-57) | No |
| Diaper, 200419 | 16 | Visual analog score from 0-100 (100 = best) (SD) | Placebo: 49.7 (11.1) Valerian 300 mg: 47.0 (10.8) Valerian 600 mg: 49.5 (8.3) | No |
| Donath, 200012* | 16 | Median No. of minutes to fall asleep (1st-3rd quartiles) | Baseline: 60.0 min (30.0-90.0) Placebo: 60.0 min (30.0-105.0) Valerian: 45.0 min (17.5-75.0) | No |
| Balderer, 198514* | 10 | Mean No. of minutes to fall asleep (SEM) | Placebo: 23 min (5) Valerian 450 mg: 18.5 min (8) Valerian 900 mg: 9 min (3) | Yes P < .01 |
| Leathwood, 198515 | 8 | 9-point scale, 9 is best score (SD) | Placebo: 4.9 points (0.4) Valerian 450 mg: 4.3 points (0.4) Valerian 900 mg: 4.9 points (0.3) | No |
| Francis, 200216* | 5 | Mean No. of minutes to fall asleep, reported by parents (SD) | Baseline: 41.1 min (21.0) Placebo: 39.1 min (34.7) Valerian: 23.4 min (13.4) | No |
SD = standard deviation; CI = confidence interval; SEM = standard error of mean.
*
Of four studies reporting subjective sleep-onset latency in minutes, two reported statistically significant benefits.