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? Here, experts spill the tea on whether or not this is a trend worth trying. “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.” Stephenson also notes that other research (again, not done on humans) has found that lettuce extract combined with other herbs like skullcap3 can increase time spent in REM sleep. But it’s unclear how much of that is due to the lettuce, and how much is the skullcap—which is more often used as a sedative4. However, she does add that lettuce seed oil has long been prized as a sleep aid in Korea5, so it’s possible that science is still catching up to this traditional medicine. 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. And if sipping lettuce water isn’t your thing, Stephenson has a more palatable way to put this research into practice: Eat a salad containing romaine for dinner. “You’ll get great nutritional benefits and fiber, along with the possibility of some pain relief and an easier time getting to sleep and staying asleep,” she says. “To me, that’s a strategy that has far more benefits than drinking lettuce water.” Emma received her B.A. in Environmental Science & Policy with a specialty in environmental communications from Duke University. In addition to penning over 1,000 mbg articles on topics from the water crisis in California to the rise of urban beekeeping, her work has appeared on Grist, Bloomberg News, Bustle, and Forbes. She’s spoken about the intersection of self-care and sustainability on podcasts and live events alongside environmental thought leaders like Marci Zaroff, Gay Browne, and Summer Rayne Oakes.
