At what age do women start having a low sex drive?
This is one of the issues that are not often discussed in the media: lower sex drive, particularly for women, remains a mystery. And yet, it affects many people. Part of the problem is that womens sexuality is a bit more complicated and complex than mens. An author on WebMD writes, Unlike men's main sexual complaint, erectile dysfunction, women's biggest sexual problem is caused by a combination of both mental and physical factors, which aren't likely to be cured by merely popping a pill.
Women between the age 18 and 59, from reaching puberty to menopause, can start experiencing low sex drive. WebMDs article on the matter includes this really neat quote, "One of first things I do in speaking to women who come in with sexual concerns is let them know that there is no normal frequency or set of behaviors and things change with time," says Jan Shifren, MD, an assistant professor at Harvard Medical School. "If it's working for them and/or their partner, there is no problem."
See, this is part of the problem. We do not know how to quantify high and low sex drives. Every person has their own norms and standards. Every couple will have their own system, their own norm. But when a woman experiences a significant decrease in interest in sex that is having an effect on her life and is causing distress, then it's considered a problem of low sexual desire or HSDD. 
Right? When it becomes problematic and starts causing you issues in the relationship, then it is time to start considering it a problem. Kingsberg says that sexual desire is more than just an issue of low libido or sex drive. She says sexual drive is the biological component of desire, which is reflected as spontaneous sexual interest including sexual thoughts, erotic fantasies, and daydreams. 
Kingsberg also raises an important point: sex drive decreases by age for a lot of people. That sexual drive declines naturally with age based on physiological factors. But sexual desire also encompasses interpersonal and psychological factors that create a willingness to be sexual. 
Then the article includes several reasons that women start to have low sex drive, Interpersonal relationship issues. Partner performance problems, lack of emotional satisfaction with the relationship, the birth of a child, and becoming a caregiver for a loved one can decrease sexual desire. Sociocultural influences. Job stress, peer pressure, and media images of sexuality can negatively influence sexual desire. Low testosterone. Testosterone affects sexual drive in both men and women. Testosterone levels peak in women's mid-20s and then steadily decline until menopause, when they drop dramatically. Medical problems: Mental illnesses such as depression, or medical conditions, such as endometriosis, fibroids, and thyroid disorders, impact a woman's sexual drive both mentally and physically. Medications: Certain antidepressants (including the new generation of SSRIs), blood pressure lowering drugs, and oral contraceptives can lower sexual drive in many ways, such as decreasing available testosterone levels or affecting blood flow. Age. Blood levels of androgens fall continuously in women as they age. 


