Supplementing with a tiny amount of the extract of the oh-so-common cucumber appears to have a positive effect on mental health. A US human study suggests that a daily dose of 20 milligrams of the extract improves sleep and reduces feelings of stress and anxiety.

Study
In the summer of 2025, researchers at the University of North Florida published a study in Health Science Reports involving 80 adult volunteers.

The researchers divided the subjects into two groups. For two months, one group took a placebo daily, half an hour before bedtime. The other group took 20 milligrams of a cucumber extract.

The researchers used Q-actin, an alcohol-based extract standardized for the iminosugar idoBR1. Q-actin is a product of Gateway Health Alliances, the study's sponsor.

Fresh cucumber
Last week, we also wrote a post about supplements containing cucumber extracts. We estimateded that a dose of 20 milligrams of extract is equivalent to 200-400 grams of fresh cucumber. A standard supermarket cucumber weighs about 350 grams.

Results
Just before the study began and on the last day of supplementation, the participants completed questionnaires that gave the researchers an insight into their mental health. Overall, they observed a positive trend in the participants who had received Q-actin [Cucumis sativus] compared to the control group, but none of the differences were statistically significant.

This is shown in the table below. Click on it for a larger version.

Conclusion
The subjects who received Q-actin slept better. The placebo group also showed an improvement, but the improvement was smaller. Furthermore, on the last day of the trial, there was little difference between the sleep quality of the two groups. The difference between the scores of the two groups was not statistically significant.

The same was true for the subjects' perception of stress and feelings of anxiety and worry. This is evident in the figures below.

Click on the figures to see a larger version.

"Although the interaction effects were not significant, the results revealed that Cucumis sativus supplementation led to improved health related quality of life, mood, sleep quality, and decreased anxiety and perceived stress levels", the researchers summarize.

"These preliminary findings suggest the potential of Cucumis sativus as a beneficial supplement for overall health-related quality of life. Cucumis sativus extract could serve as an effective alternative to synthetic antioxidants and anti-inflammatory drugs currently available."

"Further research with larger sample sizes is needed for a comprehensive understanding of its mechanisms and long-term effects."