Supplementation with 400 milligrams of chamomile extract improves sleep quality. This is shown in a trial published in 2017 in Complementary Therapies in Medicine.

Study
Researchers from Kashan University of Medical Sciences in Iran recruited sixty healthy individuals over 60 with moderate sleep problems and divided them into two groups.

During the four weeks of the trial, subjects in the placebo group received two capsules without bioactive substances daily, while subjects in the experimental group took two capsules containing a chamomile extract daily.

Each chamomile capsule contained 200 milligrams of extract. It was extracted from chamomile using a 70 percent ethanol solution. The researchers used a product from Ahura Pharmaceutical Company.

Before the experiment began, the researchers checked whether the subjects had an allergic reaction to chamomile. Approximately three percent of all adults are allergic to chamomile.

Just before supplementation began and on the last day of the supplementation period, the researchers administered a standardized questionnaire to their subjects - the Pittsburgh Sleep Quality Index [PSQI] - which measures sleep problems. They did this again two weeks after the supplementation period had ended.

Results
Supplementation with 400 milligrams of extract per day lowered the PSQI by three points. This indicates a clinically significant improvement in sleep. Nevertheless, the subjects still experienced moderate sleep problems after four weeks of supplementation.

Click on the figure and the table below for a larger version.

Two weeks after the supplementation period had ended, the subjects in the experimental group still reported an improvement in sleep quality.

Supplementation had no effect on sleep duration. However, the subjects in the chamomile group fell asleep sooner, slept through the night more often, and, above all, slept better.

Mechanism
Chamomile contains dozens of potentially active substances. Of these, apigenin is particularly interesting, the Iranians suspect.

"Review studies showed the effectiveness of chamomile in managing insomnia and producing tranquilizing effects and attributed its effects to its apigenin and flavonoid compounds which bind benzodiazepine receptors in the brain," they write. [Planta Med. 1995 Jun;61(3):213-6.]

Conclusion
"The use of chamomile extract can significantly improve sleep quality among elderly people," the Iranians summarize.

"Given the high prevalence of sleep disturbances among elderly people and the adverse effects of hypnotic medications, chamomile extract can be used as a safe modality for promoting elderly people's sleep."