When the Food and Drug Administration approved Viagra in 1998 to treat erectile dysfunction, it changed the sexual landscape for older men, adding decades to their vitality. Meanwhile, older women with sexual problems brought on by aging were left out in the cold with few places to turn besides hormone therapy, which isn't suitable for many or always recommended as a long-term treatment.

Now, propelled by a growing market of women demanding solutions, new treatments are helping those who suffer from one of the most pervasive age-related sexual problems.

Genitourinary syndrome of menopause, brought on by a decrease in sex hormones and a change in vaginal pH, is characterized by vaginal dryness, shrinking of tissues, itching and burning, which can make intercourse painful. GSM affects up to half of post-menopausal women, and can contribute to bladder and urinary tract infections and incontinence. Yet only 7 percent of post-menopausal women use a prescription treatment for it, according to a recent study.

The new remedies range from pills to inserts to a five-minute laser treatment that some doctors and patients are hailing as a miracle cure.

The lag in addressing GSM has been partly the result of a long-standing reluctance among doctors to view post-menopausal women as sexual beings, said Leah Millheiser, director of the Female Sexual Medicine Program at Stanford University.

"Unfortunately, many clinicians have their own biases and they assume these women are not sexually active, and that couldn't be farther from the truth, because research shows that women continue to be sexually active throughout their lifetime," she said.

With today's increased life expectancy, that can be a long stretch — an additional 30 or 40 years for a typical woman who begins menopause in her early 50s.

"It's time for clinicians to understand that they have to bring up sexual function with their patients whether they're in their 50s or they're in their 80s or 90s," Millheiser said.

[This medical epidemic plagued women, but for years no one talked about it]

By contrast, doctors routinely ask middle-aged men about their sexual function and are quick to offer prescriptions for Viagra, said Lauren Streicher, medical director of the Northwestern Medicine Center for Sexual Medicine and Menopause.

"If every guy, on his 50th birthday, his penis shriveled up and he was told he could never have sex again, he would not be told, 'That's just part of aging,' " Streicher said.

Iona Harding of Princeton, N.J., had come to regard GSM, also known as vulvovaginal atrophy, as just that.

For much of her marriage, she and her husband had a "normal, active sex life." But after menopause, sex became so painful that they eventually stopped trying.

"I talked openly about this with my gynecologist every year," said Harding, 66, a human resources consultant. "There was never any discussion of any solution other than using estrogen cream, which wasn't enough. So we had resigned ourselves to this is how it's going to be."

A push for sexual equality

It is perhaps no coincidence that the same generation of women who first benefited widely from the birth control pill in the 1960s are now demanding fresh solutions to keep enjoying sex.

"The Pill was the first acknowledgment that you can have sex for pleasure and not just for reproduction, so it really is an extension of what we saw with the Pill," Streicher said. "These are the women who have the entitlement, who are saying, 'Wait a minute, sex is supposed to be for pleasure and don't tell me that I don't get to have pleasure.' "

The push for a "pink Viagra" to increase desire highlighted women's growing demand for sexual equality. But the drug flibanserin, approved by the FDA in 2015, proved minimally effective.

For years, the array of medical remedies has been limited. Over-the-counter lubricants ease friction but don't replenish vaginal tissue. Long-acting moisturizers help plump up tissue and increase lubrication, but sometimes not enough. Women are advised to "use it or lose it" — regular intercourse can keep the tissues more elastic — but not if it is too painful.

Systemic hormone therapy that increases the estrogen, progesterone and testosterone in the body can be effective, but if used over many years it carries health risks, and it is not always safe for cancer survivors.

Localized estrogen creams, suppositories or rings are safer, because the hormone stays in the vaginal area. But they can be messy, and despite recent studies showing that such therapy is not associated with cancer, some women are uncomfortable with its long-term use.

In recent years, two prescription drugs have expanded the options. Ospemifene, a daily oral tablet approved by the FDA in 2013, activates specific estrogen receptors in the vagina. Side effects include mild hot flashes in a small percentage of women.

Prasterone DHEA, a naturally occurring steroid that the FDA approved last year, is a daily vaginal insert that prompts a woman's body to produce its own estrogen and testosterone. However, it is not clear how safe it is to use long term.

'With each treatment, it got better'

And then there is fractional carbon dioxide laser therapy, developed in Italy and approved by the FDA in 2014 for use in the United States. Similar to treatments long performed on the face, it uses lasers to make micro-abrasions in the vaginal wall, which stimulate growth of new blood vessels and collagen.

The treatment is nearly painless and takes about five minutes; it is repeated two more times at six-week intervals. For many patients, the vaginal tissue becomes thicker, more elastic and more lubricated almost immediately.

Harding began using it in 2016, and after three treatments with MonaLisa Touch, the fractional CO2 laser device that has been most extensively studied, she and her husband were able to have intercourse for the first time in years.

Cheryl Edwards, 61, a teacher and writer in Pennington, N.J., started using estrogen in her early 50s, but sex with her husband was painful and she was plagued by urinary tract infections requiring antibiotics, along with severe dryness.

After her first treatment with the MonaLisa Touch a year and a half ago, the difference was stark.

"I couldn't believe it . . . and with each treatment, it got better," she said. "It was like I was in my 20s or 30s."

Although studies on MonaLisa Touch have been small, doctors who use it range from cautiously optimistic to heartily enthusiastic.

"I've been kind of blown away by it," said Streicher, who, along with Millheiser, is participating in a larger study comparing it to topical estrogen. Using MonaLisa Touch alone or in combination with other therapies, she said, "I have not had anyone who's come in and I've not had them [be] able to have sex."

Cheryl Iglesia, director of female pelvic medicine and reconstructive surgery at MedStar Washington Hospital Center in the District, was more guarded. Although she has treated hundreds of women with the MonaLisa Touch and is participating in the larger study, she noted that studies have looked only at short-term effects, and less is known about using it for years or decades.

"What we don't know is: Is there a point at which the tissue is so thin that the treatment could be damaging it?" she said. "Is there priming needed?"

Millheiser echoed those concerns, saying she supports trying local vaginal estrogen first.

So far, the main drawback seems to be the price. An initial round of treatments can cost $1,500 to $2,700, plus an additional $500 a year for the recommended annual touch-up. Unlike hormone therapy or Viagra, the treatment is not covered by insurance.

Some women continue to use local estrogen or lubricants to complement the laser. But unlike hormones, which are less effective if begun many years after menopause, the laser seems to do the trick at any age. Streicher described a patient in her 80s who had been widowed since her 60s and had recently begun dating a man.

It had been 20 years since she had been intimate, Streicher said. "She came in and said, 'I want to have sex.' " After combining the MonaLisa Touch with dilators to gradually reenlarge her vagina, the woman reported successful intercourse. "Not everything is reversible after a long time," Streicher said. "This is."

But Iglesia said she has seen a range of responses, from patients who report vast improvement to others who see little effect.

"I'm confident that in the next few years we will have better guidelines, [but] at this point, I'm afraid there is more marketing than there is science for us to guide patients," she said. "Nobody wants sandpaper sex; it hurts. But at the same time, is this going to help?"

The laser therapy also can help younger women who have undergone early menopause because of cancer treatment, including the 250,000 a year who receive breast cancer diagnoses. Many cannot safely use hormones, and often they feel uncomfortable bringing up sexual concerns with doctors who are trying to save their lives.

"If you're a 40-year-old and you get cancer, your vagina might look like it's 70 and feel like it's 70," said Maria Sophocles, founding medical director of Women's Healthcare of Princeton, who treated Edwards and Harding.

After performing the procedure on cancer survivors, she said, "tears are rolling down from their eyes because they haven't had sex in eight years and you're restoring their femininity to them."

The procedure also alleviates menopause-related symptoms in other parts of the pelvic floor, including the bladder, urinary tract and urethra, reducing infections and incontinence.

Ardella House, a 67-year-old homemaker outside Denver, experienced incontinence and recurring bladder infections as well as painful sex. After having the MonaLisa Touch treatment last year, she became a proselytizer.

"It was so successful that I started telling all my friends, and sure enough, it was something that was a problem for all of them but they didn't talk about it either," she said.

"I always used to think, you reach a certain age and you're not as into sex as you were in your younger years. But that's not the case, because if it's enjoyable, you like to do it just as much as when you were younger."