I've recently written about reishi mushroom (also known as lingzhi or the "mushroom of immortality") and its role in improving sleep (https://www.brainwaveusa.com/blogs/dr-andys-answers-medicinal-mushroom-questions/i-reishi-i-could-sleep). Traditionally, reishi has been used as an adaptogen to help the body manage stress, promote relaxation, support the immune system, and enhance overall well-being. Now, a new large-scale randomized controlled clinical trial adds to the growing evidence supporting reishi's effects on sleep.
The new study was presented last month at the SLEEP 2026 conference in Baltimore, MD, the 40th annual meeting of the Associated Professional Sleep Societies (APSS). Dr. Ching Xie of Brooklyn Unity Medical Care presented the new study, which enrolled 218 adults with chronic insomnia, with 209 participants completing the full 8-week trial. Participants were recruited in late 2025 and early 2026 and were randomly assigned to receive either 980 mg of reishi extract or 5 mg of melatonin each night (https://www.sleepmeeting.org/wp-content/uploads/2026/05/SLEEP-2026-Late-Breaking-Abstracts.pdf: page 14).
The researchers evaluated participants using the Insomnia Severity Index (ISI), a validated questionnaire that measures several aspects of insomnia (ranging from 0-28). It asks participants to rate difficulty falling asleep, staying asleep, waking too early, overall satisfaction with sleep, how noticeable their sleep problems are to others, how much they worry about their sleep, and how much insomnia interferes with daily life. Severe insomnia is classified as 22-28 while moderate insomnia is scored at 15-21 on this scale. Minimal sleep disruption is scored at 8-14 and no disruption is 0-7.
After 8 weeks, both groups improved, but the reishi group experienced significantly greater benefits. ISI scores decreased by an average of 8.7 points in the reishi group compared to 5.6 points in the melatonin group, which was a statistically significant difference. The findings remained significant after adjusting for age, sex, and baseline insomnia severity. Importantly, no adverse events were reported during the study, meaning that reishi consumption is safe.
This is one of the largest randomized trials to date utilizing reishi and provides encouraging evidence that reishi may be an effective option for improving sleep.
At Brain Wave, we have long recognized reishi as one of the most promising functional mushrooms for supporting healthy sleep, and it is always part of our blend. In fact, we are currently developing a new sleep formula with reishi as the star ingredient. As always, we'll continue following the science and sharing the latest research as it emerges.
Cheers,
Dr. Andy