“I’d really like to get off of birth control. I’ve been on these hormones so long, I don’t even really know who I am without them. But until we’re married, I just don’t want to risk it.” So said a young woman my husband and I were recently counseling (along with her fiance) on fertility awareness, as part of our volunteer work with the Couple to Couple League.

What, exactly, are these “hormones” with which everyone is suddenly so concerned? The term is currently so ubiquitous that it’s become something of a buzzword, especially in relation to women’s health. In fact, it’s now common practice among the health-conscious set to avoid milk and other animal products that have been treated with hormones and to actively seek out beauty products and household cleaners that won’t disrupt our endocrine systems (aka, our hormones).

Of course as women, we’ve also long been assured of the safety of hormonal birth control, which, we’ve been told, is simply made up of the same hormones produced by our bodies. But increasingly, women are asking if that’s really true. And if it’s not, how do the hormones in birth control differ from the hormones naturally occurring in a woman’s body? Most importantly, why does it matter?

To answer that question, we need to break down the concept of hormones—and especially the female reproductive hormones responsible for the menstrual cycle and fertility. Once we women understand the hormones that matter most for our feminine health and well-being, we will be able to get the help we need if we suspect those hormones are unbalanced.

Estrogen, progesterone, and testosterone

Hormones are “chemical messengers that travel through the bloodstream to send messages to tissues or organs.” Both men’s and women’s bodies make many of the same hormones, which are necessary for various aspects of bodily function. Even the sex hormones of estrogen, progesterone, and testosterone are produced by both men and women, but the amounts of these hormones and the effects they have on the body varies distinctly between men and women.

That said, the hormones that most set women apart from men are estrogen and progesterone. Produced within the ovaries, these female sex hormones are necessary for reproduction and female secondary sex characteristics (like an hourglass shape and a lack of facial hair). Their cyclical rise and fall is responsible for the monthly menstrual cycle, without which a woman would not ovulate, have a period, or be able to conceive a baby.

Testosterone is known as the male sex hormone, because it is produced in large amounts by the testes. Like progesterone and estrogen in women, testosterone is responsible for male reproductive capacity and secondary sex characteristics (like facial hair and broad shoulders). However, just as progesterone and estrogen are produced in small amounts (and play an important role) in men’s bodies, testosterone also has an important role to play in female reproductive health (despite being present in much smaller amounts in women than in men).

How your hormones work together to give you your menstrual cycle—and your fertility

Estrogen and progesterone are the hormones most responsible for a woman’s menstrual cycle, and therefore, her fertility. During the first half of a woman’s cycle, estrogen levels peak as the inner lining of the uterus (the endometrium) is thickening in preparation for possible implantation of a fertilized egg (embryo). During the last half of the cycle, progesterone levels peak to maintain the endometrium in case of implantation. The turning point is ovulation, when an egg is released from one of the ovaries, a phenomenon which occurs roughly in the middle of the cycle. 

As Cassondra Moriarty described for Natural Womanhood, one can think of estrogen as “the grower” and progesterone as “the glue.” That is, “estrogen grows endometrial tissue, while progesterone holds it all together.”If an embryo does not implant, the endometrium is sloughed off as both progesterone and estrogen levels take a nosedive at the end of the cycle. The result? Your period. Simply put, without the dual roles of estrogen and progesterone, a woman’s womb is not a hospitable enough place for the implantation of a fertilized egg, and pregnancy would be impossible.

But that’s not the whole story. We can’t forget the other important ovarian hormone with a lesser (albeit still important) impact on feminine reproductive health: testosterone. Like estrogen and progesterone, testosterone is also produced by the ovaries. Among other things, testosterone in women is responsible for a woman’s libido or sex drive, which tends to peak around the time of ovulation.

There are other important hormones produced outside the ovaries—namely, in the brain—that come into play throughout the cycle. These include gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), whose interplay is responsible for the maturation and release of an egg from one of the ovaries. Prolactin is another hormone produced by the brain with an impact on the ovulatory portion of the menstrual cycle. In breastfeeding women, high levels of prolactin inhibit the release of an egg from the ovaries.

Signs of hormonal imbalance

The cooperation of these various hormones exists in a delicate balance. When the appropriate levels of these hormones are affected—either by outside stress on the body or by an underlying pathology—the result can be an irregular, painful, or otherwise “wonky” menstrual cycle, among other symptoms.

One key way women frequently identify hormonal imbalances and issues with their menstrual cycle is when they’re trying to get pregnant . . . and can’t. But the good news is that you don’t need to be trying to get pregnant to discover issues with your menstrual cycle or to get the help you deserve for those issues. The growing field of restorative reproductive medicine (RRM) exists to help women identify cycle issues (ideally long before they’re trying to get pregnant), treating their menstrual cycles as the “Fifth Vital Sign” they truly are.

What sets RRM providers apart is their dedication to discovering the underlying issue manifesting in cycle irregularity. Not only are they trained to read a woman’s detailed menstrual cycle charts, but along with other signs, symptoms, and diagnostic tests, RRM providers can help identify issues like endometriosis, polycystic ovary syndrome (PCOS), luteal phase defect, and more, which are often the root causes behind, or are associated with, the telltale symptoms of a hormonal imbalance.

There are a number of common signs of an underlying hormonal imbalance, for which women are routinely placed on hormonal birth control. Among these are a cycle (that is, the time between periods) that is consistently shorter than 21 days or longer than 36 days, a cycle length that consistently varies by 5 or more days, mid-cycle spotting or bleeding, and very heavy and/or prolonged bleeding during your period.

When navigating these signs or symptoms, an RRM provider will likely run tests to check the levels of various hormones, especially estrogen, progesterone, and testosterone. Too little or too much of any of these hormones—or the improper balance of them in relation to one another—can cause a lot of problems. An especially thorough provider will also test other hormones, including thyroid hormones, which can have an impact on a woman’s reproductive health and fertility. In order to take full advantage of all that an RRM provider can provide, women need to become familiar with observing and tracking their menstrual cycles by learning a Fertility Awareness Method (FAM), which teaches women these necessary health-tracking and maintenance skills.

Now, what was that about birth control?

So back to the question of birth control. It is true that the hormones found within hormonal birth control (including the Pill, the patch, the vaginal ring, the arm implant, and the hormonal IUD) are similar to the hormones naturally produced by the female body. They are, in fact, synthetic versions of estrogen and progesterone, the most commonly used of which are synthetic estradiol and progestin. Some versions of hormonal birth control are progestin-only, but most are some combination of estradiol and progestin.

The function of the synthetic hormones found in birth control is to suppress the body’s natural, cyclical production of estrogen and progesterone with a low, constant dose of synthetic hormones, thereby preventing ovulation and overriding the menstrual cycle.

So it’s not accurate to say that birth control “regulates” your period (as women are often told), but rather, it suppresses the cycle from happening at all. Doctors frequently prescribe hormonal birth control when a woman presents with heavy, irregular, or painful periods (among other things), both because it “levels out” a woman’s hormones and, as the logic goes, “no menstrual cycle equals no menstrual cycle disorder.”

While hormonal birth control can be effective at controlling some of the symptoms experienced by a woman with a hormonal imbalance, it does nothing to correct the underlying imbalance—which will still be there when the woman goes off of birth control. As thyroid health advocate Laurie Christie King put it in an interview with Natural Womanhood, one can think of hormonal birth control as a “doctor-prescribed hormonal imbalance.” Furthermore, as detailed in the book This is Your Brain on Birth Control by Dr. Sarah E. Hill, this suppression of naturally-produced (endogenous) hormones has implications for other aspects of women’s health, including mental health and well-being.

Simply put, a woman’s body needs her hormones, and it needs them in the right balance to function as it ought. Young women especially need to ovulate regularly, and they need to have healthy periods. Whether you’re looking to get pregnant, to not get pregnant, or you just want to know more about your reproductive health in order to take better care of yourself, your hormonal health is truly essential.