IV drips — the kind you might get if you're rushed to the hospital — are trending as a spa treatment, thanks in part to endorsements by celebrities like Kim Kardashian and Madonna.

Why it matters: Like other "wellness" trends with a whiff of medical imprimatur, IV nutrient drips can be harmless or mildly restorative — or go awry, particularly in the wrong hands.

Doctors aren't too concerned but scoff at the promises and price tags, saying clients are just paying for rapid hydration that bypasses the stomach.

What's happening: IV drip spas have opened across the country — not just in trendsetting cities like New York and Los Angeles, but also in suburbia and middle America.

What they're saying: "IV therapy greatly benefits athletes, patients with compromised GI and immune systems as well as patients with low energy and excess stress," according to Atlas Health Medical Group of Gilbert, Arizona, which is run by two naturopathic physicians.

The other side: "These treatments are mostly harmless and really just result in people making expensive urine," says Torbati.

The back story: Intravenous vitamin therapy is widely traced to a Baltimore doctor named John A. Myers, who, before his death in 1984, administered infusions that became known as "Myers' cocktail."

Caveat emptor: Reports of IV drips gone wrong are sporadic but worrisome.

Editor's note: This story was originally published on Dec. 1.