UTI Treatment: What to Know About Supplements and Prevention

Still, there is some evidence that the individual ingredients in these supplements may provide a slight benefit, especially for people with frequent U.T.I.s — and they’re unlikely to have significant side effects, said Dr. Monica Woll Rosen, an OB-GYN at University of Michigan Medical School.

Cranberry, the most common ingredient in U.T.I. supplements, has long been touted as an at-home elixir to ward off the infection. There’s encouraging, but scant, data to support this: A 2017 meta-analysis found that cranberry reduced the risk of developing a U.T.I. by 26 percent in otherwise healthy women with a history of urinary infections, but the studies had small numbers of participants.

The American Urogynecologic Society issued a Best Practice Statement for recurrent urinary tract infection in adult women that states “the preponderance of evidence does not support routine use of cranberry products in the care of women with” recurrent U.T.I.s.

In 2020, the F.D.A. concluded that there is “limited credible scientific evidence” to suggest that certain cranberry supplements and beverages would lower the risk of recurrent U.T.I.s.

Many U.T.I. supplements also contain d-mannose, a simple sugar related to glucose. A review of previous studies on the chemical found that it may provide protection against recurring U.T.I.s. “Overall, d-mannose appears to be effective when compared to a placebo,” said Dr. Lenger, the lead author of the review. “But that’s taken with the caveat that this is a small amount of data.” In large doses, d-mannose may cause gastrointestinal side effects, like diarrhea and flatulence, she added, but overall, most people tolerate it well.

Vitamins, especially vitamin C, are also present in many of the supplements that claim to protect against urinary tract infections. Some doctors think that vitamin C can combat bacterial growth, in combination with other supplements, by theoretically acidifying the urine, said Dr. Jerry Lowder, a urogynecologist at Washington University in St. Louis School of Medicine.

“With any therapy, you’ve got to think: What’s the risk, what’s the benefit?” Dr. Brucker said. “If there’s a low risk, and there’s some data that says it might work, it might be reasonable for a doctor to say, let’s consider these remedies.”