Moody Bitches: The Truth about the Drugs You’re Taking, the Sleep You’re Missing, the Sex You’re Not Having and What’s Really Making You Crazy.... Julie Holland

      Some women are simply more sensitive to hormones affecting their moods than others are. The Pill works by presenting just enough estrogen and progesterone to the pituitary that it thinks ovulation has already occurred and so won’t trigger the follicle to release an egg. Estrogen and serotonin regulate each other in a complicated dance, like so many things in the brain and body. Anything that affects estrogen is going to have an impact on serotonin. One possible reason the Pill may make some women a bit bonkers: estrogen causes the manufacture of a serotonin receptor called 5HT2A. This is the receptor that mediates the effects of hallucinogens like LSD and is the target of some antipsychotic medications. About a third of women have variations on this receptor that may cause problems when estrogen levels are higher.

      But the bigger culprit is likely the progesterone. Synthetic progestin is horrible for your mood, and about 10 percent of women really can’t tolerate it at all. The oral contraceptive Yaz is preferable when it comes to mood effects, perhaps due to one component, drospirenone, which is more similar to natural progesterone than other synthetics are, or due to the fact that it acts more like a diuretic, lessening water retention during the premenstrual phase. (Being bloated does bad things to your brain.)

      Another reason oral contraceptives may worsen mood is that synthetic hormones seem to interfere with tryptophan metabolism and vitamin B₆ levels, both of which are necessary to make serotonin. If you’re on the Pill, you should supplement with B₆.

      You could say that the Pill basically tricks your body into thinking it’s pregnant already, so that no egg gets released. Also, the cervix becomes plugged up with thick mucus, the way it does in pregnancy. Because there is no thinner cervical mucus flowing, the Pill can make your vagina drier, and sex may become painful. If you’re not on the Pill, your cervical mucus is an easy way for you to track your cycle and fertility. Midcycle, the mucus is runny like egg whites. When you’re fertile, nature ensures you’ll be naturally more lubricated when you need it. On the Pill, you’re not fertile, so there is less mucus and you’re not well lubricated.

      For many women, the Pill makes their skin clearer; estrogen does help give you that peaches-and-cream complexion. Your breasts tend to get a bit larger on the Pill, just as they do in pregnancy, likely due to the steady progesterone levels the Pill provides. So lighter periods, less acne, and lovely boobs sound great, I know, but there are some downsides to being on the Pill. First, there is the issue of weight gain, but, more accurately, a change in weight distribution. Estrogen dictates where fat gets placed in the body. It makes you put on weight in your hips and thighs, and also in the backs of your arms. There is a logical reason for this. Women of childbearing potential need a different center of gravity. If you’re going to carry a baby in your belly, you need ballast in your backside; estrogen tends to make your stomach flatter because that’s not where fat distribution is needed. (FYI, when you’re perimenopausal, your belly starts to store fat because your estrogen levels are waning. Beware the menopot.)

      Second, oral contraceptives can really cut into your sexual desire. I tell my patients this is the “dirty little secret” of the Pill. For some women, being liberated from the fear of unwanted pregnancy may allow them to relax and experience sexual pleasure more, but a slew of other women are unhappy to discover that their desire for sex and their ability to achieve orgasm are muted by being on the Pill. There are two factors at work here. The first is, the longer you’re on the Pill, the lower your testosterone levels become, and the less horny you are over time. Taking extra estrogen orally increases levels of something called sex hormone binding globulin (SHBG), a protein in the blood that binds up testosterone, so you end up with lower circulating levels of “free” testosterone, one-tenth to one-twentieth of normal. If the hormone is bound up, it doesn’t hit the receptor, so it’s useless to your brain. It gets worse: a research study showed that women who’d been off the Pill for four months still had SHBG levels four times that of normal. When I spoke with one of the investigators, he told me it never returns to normal. Another gynecologist told me, “It should be a warning on the box,” but instead it’s something no one seems to talk about.

      Testosterone, while twenty times more prevalent in men, is also present in women, and it is the primary hormone responsible for sexual drive and desire. Part of every woman’s monthly cycle includes testosterone levels that rise and fall, peaking just as fertility peaks, midcycle. Normal testosterone levels not only vary throughout the cycle but also go up and down throughout the day (higher in the morning in most women) and in response to various circumstances and behaviors (rising after vigorous exercise, success at work, and having regular sex). Women’s testosterone levels tend to be highest in their early twenties and fall after menopause, after all the other hormones have declined. So not only is there a peak in testosterone midcycle but there may also be one during a brief, magical time right around age forty, a woman’s “sexual peak,” where testosterone levels are relatively higher than those of the other hormones. When you’re on the Pill, you miss out on all of that.

      Ovulation and Pheromones: Choosing a Cad or a Dad

      Many women have significant shifts not just in their hormones but in their horniness all month long. It wasn’t until my forties that I became aware of how much my libido, and, more important, my feelings about my husband, varied from week to week. When I read about this in a book called Sexy Mamas, I felt validated: “My husband knows that my monthly cycle provides me with about a week of feeling romantic, a week of lust, a week of slowing down, and a week of no desire. We work around that.”

      Fertility increases gradually up to ovulation and rapidly decreases afterward. Your desire to have sex naturally follows that pattern. While most primates have a period of “heat,” it is generally assumed that the human female doesn’t have such a cordoned-off time frame and is sexually available all month long, called “extended sexuality.” As you may have experienced, there are a few days in your cycle when you’re more up for sex than at other times, and, logically, Mother Nature has been smart about when that is. Women are more likely to be horny midcycle, during peak fertility, in the day or two leading up to the egg being released, when their testosterone levels are at their highest. The perfect storm of ovulation, optimum fertility, and peaking testosterone levels creates one red-hot mama (to be).

      The baboon’s backside turns bright red when she is in heat (called estrus), signaling to nearby males that she’s ready for love. Humans are not quite so overt, though our midcycle high estrogen levels do cause a subtle dilation of blood vessels in our cheeks, enhancing our natural blush. Studies show that men are more sexually attracted to women wearing red than other colors. Also, men are more likely to assume that a woman is sexually active and receptive if she is wearing red. This may be partly cultural and partly biological. Perhaps unconsciously, women know this, as we are more likely to choose to wear red when expecting to meet and chat up an attractive man.

      Ovulation is the only time every month when you’re pretty much guaranteed to be horny. Your desire is easier to arouse, and your sexual response is heightened. Greater feelings of attractiveness also peak during this time. All kinds of important things happen midcycle, when you ovulate. Oxytocin peaks, which means increased rates of orgasm and wanting to bond with others. Also, testosterone and estrogen levels are higher, which puts you in an ultrareceptive and horny place. Your pupils even dilate more in response to seeing your sex partner when you’re midcycle, but not if you’re on the Pill.

      We have a repertoire of not-so-covert behavior that makes it clear we’re fertile. Women