Has your “Netflix and chill” become more “Netflix and can we just keep watching Netflix?”

Sexual desire and drive is as individual as the woman who experiences it. Ask your female friend what “sexual satisfaction” means to her and the frequency, methods, and psychological associations with that phrase could be very different from yours. Same with her drive to want to have sex. What we do all have in common, though, are the hormones that trigger sexual desire.

Our Bodies, Ourselves, publishers of the landmark book of the same name on women’s health, explains that, “Estrogen, progesterone, and testosterone all affect a woman’s desire and the physical responses of her body.” According to the Journal Hormone Behavior, desire can also fluctuate over the course of a woman’s menstrual cycle due to the increase and decrease of those hormones.

Traditionally, we may think of men as having a higher sex drive than women and the authors of “Testosterone and sexual desire in healthy women and men” explain that testosterone is “thought to account for this difference.” However, they note that often studies are singling out testosterone without taking into account “social or psychological factors.”

So, what are the other factors that contribute to our sexual desire?

Internal desire
One answer is our own internal encouragement or discouragement of those desires. In the late 1990’s, two researchers at the Kinsey Institute developed a theory of sexual response called the Dual Control Model. Masters and Johnson (yes, those two) had already pioneered the work that led to classifying the four stages of sexual excitement (Excitement, Plateau, Orgasm, Resolution). What the Dual Control Model did, some thirty years later, was explain not just the mechanics of arousal, but how the body gets to arousal through the Sexual Excitation System and the Sexual Inhibition System.

Author of Come As You Are: The Surprising New Science That Will Transform Your Sex Life, Emily Nagoski, Ph.D., writes on her website, The Dirty Normal, that the Sexual Excitation System is “the gas pedal of your sexuality” and the inhibition system is “the brakes system.” Inhibition could be “fear of performance failure (erectile dysfunction, premature ejaculation, etc) in men and fear of performance consequences (STI transmission, unwanted pregnancy, social consequences) in women.

Each individual has their own levels of SES and SIS, but probably no big surprise: women generally have more “brakes” and men have more “gas.”

Birth control
Those fears of unwanted pregnancy can also have another effect on sex drive, when it leads to taking hormonal contraceptives. Hormonal contraceptives like birth control pills or the patch, stop the ovaries’ production of testosterone. In an attempt to balance out the hormones, your body produces a protein, Sex Hormone Binding Globulin (SHBG), which, you guessed it, binds to hormones. The testosterone that’s still in your body attaches to the SHBG. Remember how testosterone is needed for arousal? It means that some women on birth control have reported experiencing diminished sex drive, but who and how much is difficult to determine.

Stress
Putting the brakes on sexual arousal can also be connected to stress. You’re probably less likely to think about getting frisky when you have a looming deadline at work or are worried about an ailing parent. The American Congress of Obstetricians and Gynecologists points out that the “interplay between organic/physical factors and psychosocial phenomena,” in other words our own personal psychology and what’s happening in our lives can change how we sexually respond.

Aging
Aging can also affect sex drive. In the Journal of Women’s Health, women from 61-89 who were asked about their sex lives “had at least one sexual dysfunction; the most common for both African American and non-Hispanic white women were lack of interest in sex and vaginal dryness.” Just as sexual desire is a combination of hormones, stimulation, and physical sensations, lack of interest in sex, even as we age, can have more than one reason. Women in the study also had higher rates of poor health, depression, and “lower satisfaction with life.”

Aging does not end desire, though, according to the Journal of American Medical Association Internal Medicine: “Women who reported greater importance of sex had higher maintenance of sexual activity.” In other words, women who saw sex and sexual contact (some desired kissing and touching as much as penetration) as important, continued to make sure it a priority.

Bottom line: sexual drive is not determined by just one thing, especially for women. All women experience variations in their sex drive over the course of their lives. If those changes are sustained or are having long term effects on you or your relationship, talk to your physician about your concerns. Your doctor may be able to help you get more satisfaction (and less Netflix).

Camille Acker is a freelance writer living in Chicago and is a co-founder of The Spinsters Union. She is the proud owner of many, many books. See more at camilleacker.com.