Written by Tabish Mehraj, PhD. The supplement significantly improved sleep quality, reduced sleep onset latency by approximately 3.8 minutes, and enhanced feelings of relaxation and vigor. It also improved glucose regulation by lowering the 1-hour postprandial glucose response by 21% and peak glucose concentrations by 16%. However, no significant effects on cognitive performance were observed.

Sleep is an essential part of our overall well-being and is important for restoring energy, promoting tissue repair, consolidating memory, and regulating key body functions, such as metabolism and immunity. Lack of sleep increases the risk of certain diseases such as obesity, heart disease, and diabetes. There is evidence that poorer regulation of glucose is associated with poorer sleep quality and duration. Dietary intake of refined sugars, starches, and refined grains negatively influences sleep quality; diets with a lower glycemic load are associated with improved sleep. Mulberry leaf extract (MLE) is rich in 1-deoxynojirimycin, which has been shown to reduce postprandial blood glucose levels. It does so by inhibiting tryptophan and α-glucosidase, which facilitates sleep initiation. This supplement could improve sleep quality, thus influencing the mood and cognitive performance.

In this placebo-controlled, double-blinded, randomized, crossover trial, the effects of a supplement containing mulberry leaf extract (MLE), tryptophan, and other vitamins (1.35 mg zinc, 12.6 mg magnesium, 1.93 mg vitamin B3, and 0.135 mg B6) on sleep quality, mood, and glucose regulation were studied. A total of 43 adults aged 25 to 50 years with sleep complaints were enrolled. Individuals received either the supplement containing 750 mg of mulberry leaf extract and 120 mg tryptophan or a control product containing 4 g of wheat protein hydrolysate every day post-meal for 14 days, following a washout period and a crossover for alternation. Sleep was analyzed by actigraphy, and glucose levels, cognitive performance, and mood were continuously monitored.

Key Findings/Results

• The study showed that the supplement improved the overall sleep quality, with a reduction in sleep onset latency (SOL), which was objectively measured and decreased by approximately 3.8 minutes, p = 0.026.

• The supplementation significantly reduced the evening meal’s postprandial glucose response by 21%, and improvements were observed in glucose regulation by reducing peak glucose concentration by 16%.

• Quality of sleep was improved (Karolinska Sleepiness Scale, −0.17, p = 0.041), with a much more relaxed feeling (Brief Mood Introspection Scale, −0.4, p = 0.003).

• The vigor dimension on the mood scale profile (0.8, p = 0.038) showed improvement, showing no significant effects on cognitive performance.

Despite the study’s potential outcomes, some limitations should be considered when interpreting the results. The most evident limitation is that multiple active ingredients are involved, and it’s nearly impossible to determine individual effects. A longer intervention time is required to determine the sustained effects. The studied population consisted of individuals who reported certain sleep complaints, but mostly without major insomnia. Therefore, the findings cannot be generalized to those with psychiatric disorders and other metabolic diseases. Another limitation is that there was a slight improvement in sleep onset latency. The supplement manufacturer funded the study, and several authors were employees of the sponsoring company. Industry sponsorship should be considered when interpreting the results, although the rigorous study design helps reduce bias. The study possesses several notable strengths. First, its randomized, double-blind, placebo-controlled crossover design minimizes bias and allows each individual to serve as their own control, increasing statistical power and reducing inter-individual variability. The researchers used subjective and objective measures, including continuous glucose monitoring, validated sleep questionnaires, actigraphy, and cognitive assessments.

Participants maintained their usual lifestyles while sleep and glucose outcomes were continuously monitored using wearable technologies, increasing the practical relevance of the findings. Another major strength was the investigation of potential mechanisms through mediation analyses. Demonstrating that reductions in postprandial glucose partly mediated improvements in sleep onset provides novel evidence supporting a causal relationship between glycemic control and sleep quality. Finally, participant adherence was exceptionally high, with a compliance rate exceeding 98%, increasing confidence that the observed effects were attributable to the intervention.

This study provides evidence that an evening supplement containing mulberry leaf extract and tryptophan can modestly improve sleep initiation, reduce postprandial glucose responses, decrease nocturnal glucose variability, and enhance next-morning mood in adults with sleep complaints. The findings suggest that targeting both glucose regulation and sleep-promoting pathways may represent a novel nutritional strategy for improving sleep quality. However, larger, longer-term studies are needed to determine the clinical significance of these effects and identify the specific contributions of the individual ingredients.

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Posted June 15, 2026.

Dr. Tabish Mehraj is a pharmaceutical scientist with expertise in pharmaceutics, drug delivery, and formulation development. She earned her PhD in Pharmaceutical Sciences from the University of Mississippi, where her research focused on the formulation, optimization, and characterization of lipid-based nanocarriers for targeted liver delivery of antimalarial therapeutics. Dr. Mehraj has also served as an ORISE Fellow at the U.S. Food and Drug Administration (FDA), where she evaluated the effects of formulation and process design on the quality and performance of intravaginal drug delivery systems and developed bio-relevant in vitro drug release testing methods. She has teaching experience in pharmaceutical and life sciences courses and has authored peer-reviewed publications, book chapters, and conference presentations. Dr. Mehraj is an active member of the American Association of Pharmaceutical Scientists and has been recognized by honor societies including Rho Chi and Gamma Beta Phi.

References:

1. Soon, C. S., Thota, R., Owen, L., Tian, L., Martin, F. P., Mantantzis, K., … & Darimont, C. (2025). Mulberry leaf extract combined with tryptophan improves sleep and post wake mood in adults with sleep complaints–A randomized cross-over study—European Journal of Nutrition, 64(3), 124.