Like many American wellness remedies, the drink is actually a repackaged ritual from another country — in this case, Italy. Known to some Italian natives as “canarino,” or canary, the drink is one of the country’s many “nonna’s remedies” that are used as a post-meal digestif, upset-stomach soother or cold killer, depending on who you ask.

Prepared by combining boiling water with a lemon peel, bay leaf and, occasionally, a drop of honey, the mixture is “an ancient remedy used by Italian grandmas to bring immediate relief to their loved ones,” said Francesco Lucatorto, a 31-year-old chef who lives in Genoa.

But in recent years, younger Italians have followed America’s footsteps and reframed it as a detox drink, often imbibed after an overindulgent night of eating and drinking. Some proponents add ginger, mint or turmeric to deepen its flavor and boost its perceived benefits.

As for what the concoction actually does … well, it’s complicated.

From a gut health standpoint, vitamin C is considered important for overall digestion and aids in the absorption of crucial vitamins like iron, said Dr. Niket Sonpal, a gastroenterologist in New York. It can also act as a laxative, meaning that if daily lemon water drinkers feel lighter, it’s probably not all in their heads.

“They’re consuming a lot of ascorbic acid and softening their stools with the hydration, so instead of going to the bathroom once every two days, they’re going every day,” Dr. Sonpal said. “Over all, that’s a good thing — better out than in.”

When it comes to skin health, there is some science to support the benefits of consuming lemon, but the details are important. Researchers are increasingly studying the impact of certain foods on glycation, a key cause of skin aging that involves sugar molecules attaching to and deteriorating proteins like collagen, according to Dr. Schaffer.