TikTok Says Lettuce Water Can Help You Sleep: What Does The Science Say?

Would you drink boiled lettuce water to fall asleep faster? The internet would. Nearly 13 million people have now viewed videos tagged #lettucewater on TikTok since influencer Shapla Hoque first shared a tutorial on the strange brew last week.

To make it, you wash a few leaves of romaine, put them in a mug, pour boiling water over them, and let them sit. Ten minutes later, that mug of warm greens in your hands can supposedly make you super sleepy. It's an intriguing, if not a little odd, bedtime ritual—but does it have any science backing it up?

Lettuce water was likely inspired by a 2017 study in the journal Food Science and Biotechnology1, conducted by researchers in Korea. This study did find that compounds in romaine lettuce had a relaxing effect, but Stacie J. Stephenson, D.C., functional medicine practitioner and author of Vibrant: A Groundbreaking Program To Get Energized, Own Your Health, and Glow, notes a few important caveats: This research was conducted on mice, and it was done using isolated plant compounds.

"According to the actual science, it is the lactucin and lactucopicrin, so-called phytochemicals or compounds found in plants, in lettuce that seem to be the 'active ingredients,' as they have a demonstrated analgesic (pain-relieving) effect similar to ibuprofen2, as well as a sedating effect. When dosed with the lactucin-containing extracts, mice fell asleep significantly sooner and slept significantly longer than the controls," Stephenson told mbg after digging into the research. However, she adds, "that's mice, not people."

Furthermore, the extracts used in this experiment were prepared using a lengthy drying, powdering, and extraction process to preserve potency. Simply popping lettuce in boiling water won't necessarily have the same effect.

"It's unlikely the compounds in lettuce tea reach the levels of the extracts used in research studies," registered dietitian Abby Cannon, J.D., R.D., CDN, suspects. "It's also unclear whether those compounds enter the water itself or if they remain in the lettuce, and whether those extracts change when exposed to heat."

The jury's in: While lettuce does seem to contain sleep-promoting compounds, it's unlikely that you'd get enough of them in lettuce water to have any real effect. So we can chalk this one up largely to the placebo effect.

You can still, of course, try the brew for yourself. "The placebo is real," says Cannon. "If you believe something works, and it's unlikely to bring harm, go for it!"

If you do, just make sure to use romaine lettuce (especially green, but red works too) as it seems to have a higher lactucin and lactucopicrin content than other greens.