Effect of herbal medicine (Hwanglyeonhaedok-tang) on insomnia with bedtime procrastination: A randomized controlled trial

Introduction Hwanglyeonhaedok-tang (Huanglian-jie-du decoction, HHT) is a traditional East Asian herbal formula with potential efficacy for insomnia. This study examined whether combining HHT with Brief Behavioral Treatment for Insomnia (BBTI) provides additional benefits for adults with insomnia and bedtime procrastination. Methods This open-label, parallel-group, superiority randomized controlled trial enrolled 44 adults aged 19–59 years with DSM-5 insomnia disorder and bedtime procrastination at a single Korean medicine hospital. Participants were randomized 1:1 to HHT decoction (3 g twice daily) combined with BBTI or BBTI alone for 4 weeks, with follow-up at week 8. The primary outcome was change in Insomnia Severity Index (ISI) score at week 4. Results At week 4 (HHT + BBTI: n=20; BBTI only: n=22), the between-group difference in ISI change was −2.49 (95% CI −5.08 to 0.11; p=0.0598), showing a trend favoring HHT + BBTI. In exploratory analysis, this difference became significant at week 8 (−2.86, 95% CI −5.32 to −0.40; p=0.0238). The Bedtime Procrastination Scale score at week 4 significantly favored HHT + BBTI (−4.09, 95% CI −7.06 to −1.12; p=0.0082). No serious adverse events occurred. Conclusions HHT combined with BBTI did not significantly improve insomnia severity at the primary endpoint of week 4, possibly reflecting limited statistical power due to early trial termination. Bedtime procrastination was significantly reduced in the HHT + BBTI group compared to BBTI alone. Further research with larger, placebo-controlled trials is warranted. Registration Clinical Research Information Service (cris.nih.go.kr)