The studies are looking at drugs that could boost sexual desire and arousal in women.

"I think it's an important problem," says Dr. Robin Kroll of the Women's Clinical Research Center in Seattle. "We have baby boomers who are not willing to throw in the towel whether it comes to long distance running or an active sex life."

It's an important problem, but also an intensely personal one.

A 36-year-old local woman trying one of the drugs through a clinical trial at Northwest Clinical Research Center in Bellevue was willing to write us this letter:

"I love my husband. He is more laid back than me. We get along great.

"About seven years ago, I noticed that my interest in sex seemed to fade and it has more or less gone away. Our intimate encounters are about once a month now and it used to be more than once a week! I hope I can fix it."

"It can cause a great deal of discord," says Kroll. "It can cause marital problems. What I try to explain to my patients who come to me with sexual dysfunction, is by the time they come to me, there are already relationship issues."

Dr. Arif Khan of NCRC agrees.

"It is a big issue. What happens is many of these women won't acknowledge it. They basically avoid contact," he says.

"What they do is tell you they're too busy with chores, they will not communicate, they'll pretend to go to sleep early. The so-called headache syndrome. So it's really that it creates a lot of tension. If you think it's a men only hiding this, women hide it. So that distances the relationship. It creates a lot of tension. Yes, relationships do break up over this. Families do break up."

Men got their sexual boost when Viagra hit the market in 1998.

While there are conflicting statistics on how many women would benefit from a similar drug, one of the drug makers says the market potential is great - with 50 million women who could use help getting back to wanting it and having it.

Dr. Khan is part of a large scale clinical trial of a drug called flibanserin.

It was developed years ago as a potential anti-depressant that flopped in clinical trials. But researchers stumbled across a side-effect: a surge in sexual desire.

In the latest tests, women take the drug twice a day and file daily reports with an electronic diary - explaining if they had or wanted sex.

It is not a quick fix.

"The key in our field is to look at things that work slowly, work over time. Because women's sexual function is obviously different than men's," says Dr. Khan.

Dr. Kroll is also studying flibanserin as well as conducting a separate trial of the drug bremelanotide, administered as a nose spray.

The spray targets arousal instead of desire, and women use it shortly before having sex.

Neither is a magic bullet.

"Sexual dysfunction is not responsive to pharmacologic intervention alone," says Dr. Kroll. "It is part of what's going on in a woman's life, her upbringing, her religious training and most importantly, her relationship. When we try to intervene, it's really important to look at the whole picture."

But both drugs show early promise with mild side effects, including nausea.

While they're not "Viagra for women", they could be a step towards re-igniting passion many women forgot existed.

For more information or to enroll in a study, contact:

Northwest Clinical Research Center

Women's Clinical Research Center

And for more information on the drugs, go to:

Palatin Technologies, Inc.

Flibanserin Randomized Withdrawal Trial

Safety Evaluation of Bremelanotide