In a study of women with menopause-related sexual discomfort, gels worked as well as prescription hormone tablets at reducing symptoms.

The researchers say the results suggest low-cost, over-the-counter moisturizers might be the best option.

Most women in the study reported some relief from their most bothersome symptoms — painful intercourse, vaginal dryness or itching — regardless of treatment. Still, not quite half the women experienced what researchers considered a meaningful decline in symptom severity.

The problems are linked with declining levels of the hormone estrogen, which happens to all women when they reach menopause.

What baffles researchers is why only about half of women experience bothersome symptoms. Without that answer, pinpointing the cause and finding the perfect solution is difficult, said Dr. Caroline Mitchell, the study's lead author.

"Until we know why, our treatments are really just pretty broad attempts," Mitchell said. "We're not targeting the true biological root cause."

Researchers enrolled 300 women at a Kaiser Permanente research institute in Seattle and at the University of Minnesota. Women were randomly assigned to one of three treatments: prescription vaginal estrogen tablets and a gel with inactive ingredients; placebo tablets and Replens over-the counter moisturizer; or placebo tablets and the inert gel. Treatment lasted 12 weeks.

The results were published Monday in JAMA Internal Medicine. The U.S. National Institutes of Health paid for the study and the researchers have no financial ties to the products studied.

A journal editorial says there have been few similar studies and most were too small to reach conclusive results.

The latest results show that prescription treatment that can cost $200 US is no better than over-the-counter moisturizers costing less than $20. The researchers noted that some women may prefer tablets to creams, which can be messy, but the extra money won't buy extra relief.

Women with troublesome symptoms "should choose the cheapest moisturizer or lubricant available over the counter — at least until new evidence arises to suggest that there is any benefit to doing otherwise," the editorial said.