Testosterone, largely responsible for your sex drive, tends to decline in your 40s, around the same time that perimenopause begins. Then, in menopause, your estrogen level usually falls steadily, which, along with a lower level of testosterone, lessens desire further. That said, hormones aren’t the whole story. This may be a significantly stressful time in our lives. Our careers may be at their busy and time-consuming peaks. We may have concerns about our children. Our own parents may be failing and need more care. Any of these things can extinguish the libido’s pilot light.The upside is that simple lifestyle changes can help. Just getting regular exercise can relieve stress and hormonal mood swings and give you energy for the things that are important to you, like sex.Why is it that women seem to experience the lion’s share of libido problems?Pinkerton: Women are complex — much more so than men in this arena. When patients ask "What can you do to fix my libido?" my response is that it’s complicated. We have to look at hormonal status, general health, relationship status and stress, to find out what’s going on.Is it common not to seek out sex the way you used to?Pinkerton: Very. As women age, they often find that they stop having the kind of everyday sexual urges they used to have. It doesn’t have to be a problem; you can redefine what successful sex is to fit your own and your partner’s wants now. In your 20s, such sex may have meant simply getting aroused and having an orgasm. Now it might be more intimate: giving massages or stimulating each other with or without an orgasm. What’s important to think about if you’re dating? Pinkerton: STDs. You have to use a condom, which surprises a lot of my patients. Women at this age are more at risk for herpes and HPV than younger women are. You also have to think about pregnancy prevention. The next-highest unintended pregnancy rate after teenagers’ is actually that of women in their 40s.What if you have kids at home? Finding time to be intimate can be difficult.Pinkerton: Morning is a great time. The house is quiet, and your sex drive is high because testosterone levels are at their peak in the morning. If you have a teenager who goes out until his midnight curfew, maybe make love at seven in the evening. Or try for later in the weekend if you’re too exhausted on Friday night.Low Libido? Blame AgingThe expert: Mary Jane Minkin, MD, clinical professor of ob-gyn at Yale and author of a Woman’s Guide to Menopause & PerimenopauseWhich symptoms indicate that hormone changes are causing a low libido?Minkin: Vaginal dryness or pain during intercourse. Before I do any fancy workups on a patient who’s experiencing these problems, I prescribe a vaginal estrogen cream, which you apply directly to the labia. That solves it for many women. Just about anyone — even breast cancer patients — can use estrogen cream.Now, let’s say we fix the dryness or pain, but the woman still has no interest and she knows it isn’t a lifestyle or a relationship issue. We’ll test her hormone levels, and then we might try systemic estrogen in pill form or testosterone. Unfortunately, in the United States we don’t have an FDA-approved testosterone for women, so I’ll do an off-label prescription of a very small dose of the type approved for men or try a testosterone cream that can be applied to the thigh or labia. This increases blood flow to the genitals, aiding arousal. There are a few adverse side effects with testosterone — like increased facial hair and acne — but with a small dose, it’s not a big deal. I had one patient call me years ago to tell me that she was noticing a few stray facial hairs after starting testosterone. I said, "Okay, we’ll just lower the dose." I’ll never forget the tone of her voice when she said, "No, no, we won’t!" The effects were worth the slight downside. With any of these treatments, I tell patients to try them for three months. If they don’t work, we reevaluate.What other age-related health issues cause libido problems?Minkin: As we get older, we take more meds, and our partners do too. Some drugs do a very dirty job on sex drive. The classic is SSRI antidepressants, such as Prozac.