What You Didn't Learn in Sex Ed but Should Really Know

If you grew up in the United States, your experience with sex education likely depended on where you lived. In some classrooms, students were handed labeled anatomical diagrams and taught about the intricacies of the menstrual cycle and pregnancy. In others, the conversation was reduced to abstinence-only lectures.

While most states are involved in some way with providing sex education in public schools, there’s no national standard for what students are taught or whether that information is even accurate. Sex education in the U.S. is notoriously inconsistent. As of 2024, only 38 states and the District of Columbia mandate sex education, and just 20 of those require the content to be medically accurate (Guttmacher Institute, 2024). The result? A student in California might learn about ovulation and menstrual cycles in middle school, while in Mississippi, where the curriculum is legally required to stress abstinence, exclude concepts related to consent, and is not required to be medically accurate, students can graduate high school with little more than a limited, potentially inaccurate, understanding of sex (SIECUS, 2023).

This is not a harmless gap in knowledge. When we leave out the foundational science behind our reproductive systems, we set people up to enter adulthood with unanswered questions and a reliance on whatever out-of-date or inaccurate resources they find online. We Google symptoms or interpret lab results with no context. And when it comes to reproductive hormones, the real messengers that govern sexual development, menstrual cycles, sperm production, and fertility, most of us are playing catch-up.

Regardless of your sex education, I highly doubt you learned about hormones, despite them being key players in the daily rhythms of our lives! For both men and women, hormones guide sexual maturation and fertility, shaping everything from monthly cycles and ovulation to testosterone production and sperm development. And yet, when it comes to hormone health, many people are starting from scratch well into adulthood.

Let’s change that. Regardless of your level of sex education, lets dive into an overview of how the most important reproductive hormones work.

The Basics:

First things first, what even is a hormone?

Hormones are chemical messengers made by glands. They travel through your bloodstream to tell different parts of your body what to do, like when to grow, digest food, or regulate mood. This system of hormone-producing and hormone-responsive tissues is called the endocrine system. It's responsible for many vital processes, including metabolism, growth and development, homeostasis, mood, sleep, and sexual function and reproduction.

The glands that act as key players in the endocrine system are located in what is known as the Hypothalamic-Pituitary-Gonadal (HPG) Axis. Let's start in the brain. The hypothalamus is located deep within the brain and is responsible for the production and release of Gonadotropin-Releasing Hormone (GnRH). GnRH finds its target receptors in another deep brain structure called the anterior pituitary gland. The anterior pituitary gland reacts to stimulation from GnRH to produce both Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). Moving outside of the brain, FSH and LH, otherwise known as gonadotropins, find their target: the gonad, either the ovary or the testes. From this point on, these hormones take two different paths, either shaping egg development in the ovary or sperm production in the testes.

Women: The Ovary and The Menstrual Cycle

The ovary is the female reproductive organ that stores and matures oocytes (eggs). It is a carefully coordinated system where cells are constantly communicating. This cellular teamwork starts before birth and continues into adulthood, playing a central role in a woman’s fertility over time.

When a female is born, she already carries about 1 to 2 million eggs. As she grows, that number gradually decreases naturally, so that by puberty, around 400,000 eggs remain. Each egg is stored inside a tiny sac called a follicle. The earliest and most inactive form of these sacs is called a primordial follicle. You can think of primordial follicles as eggs stored in a secure vault, kept in a resting state, protected from damage, and preserved for future use. This quiet, dormant state is key to maintaining long-term fertility.

Anti-Müllerian hormone (AMH) helps maintain the primordial follicle reserve by preventing too many from becoming active at once. This is why AMH levels are often measured in fertility evaluations. Higher AMH levels generally indicate a greater number of remaining primordial follicles in the ovary. It gives doctors a general picture of a woman’s ovarian reserve, or how many eggs she may still have available to become pregnant in the future.

During the follicular phase of the menstrual cycle, hormonal signals from the anterior pituitary gland, LH and FSH, begin communicating with different cells within chosen follicles in the ovary. This helps prepare follicles to grow and eventually release a mature egg.

FSH helps one follicle, called the dominant follicle, grow and mature, while LH supports estrogen production within that follicle. As the dominant follicle develops, it makes increasing amounts of estrogen, sending a signal to the brain that it’s ready for ovulation. In response, the brain releases a final burst of LH, often called the “LH surge,” which triggers ovulation. During this process, the dominant follicle swells, enzymes weaken its outer wall, and the mature egg is released from the ovary.

After ovulation, estrogen levels drop, marking the start of the luteal phase, the second half of the menstrual cycle. The now-empty follicle becomes a temporary hormone-producing structure called the corpus luteum, which secretes progesterone to prepare the body for a possible pregnancy by thickening the uterine lining. This allows a fertilized embryo to attach to the uterine wall. If the egg is not fertilized by sperm and does not attach, levels of progesterone will drop, triggering the menstrual phase of the cycle. Then the cycle begins again, typically repeating every 28 days.

Men: The Testes and Sperm Production

The testes are the male reproductive organs responsible for producing sperm and testosterone. Like the ovary, the testes are a highly organized system where different cells communicate constantly. This cellular teamwork begins at puberty and continues throughout a man’s life, playing a central role in male fertility and overall reproductive health.

At puberty, the testes begin producing sperm continuously in tiny structures called seminiferous tubules. These tubules are where immature sperm cells develop and mature over time, ultimately so they can travel and meet an egg for fertilization. Maintaining a steady supply of healthy sperm requires precise hormonal signals and support from surrounding cells. This ongoing process is essential for fertility and influences hormone levels that affect many other aspects of male health.

In male bodies, FSH and LH act within the testes to support the production of testosterone and spermatogenesis (sperm production).

LH signals the testes to produce androgens, a group of hormones that includes testosterone. Testosterone supports many aspects of male reproductive health, including the production and maturation of sperm. Working alongside FSH, LH helps regulate the environment within the testes to ensure sperm cells develop properly. FSH specifically supports sperm production by helping early sperm cells grow, mature, and avoid early cell death within the seminiferous tubules, maintaining a healthy and functional sperm supply over time.

LH signals the testes to produce androgens, a group of hormones that includes testosterone. Testosterone supports many aspects of male reproductive health, including the production and maturation of sperm by regulating the environment within the testes to ensure sperm cells develop properly. FSH also supports sperm production, but it does so by helping early sperm cells grow, mature, and avoid premature cell death within the seminiferous tubules. These hormones communicate within the testes to ultimately maintaining a healthy and functional sperm supply over time.

Why Should You Care?

Ok, deep breath. It’s a lot, I know. But now that you’ve had a brief overview of reproductive hormones and the roles they play in the body, let’s revisit why understanding hormones should have been part of sex education in the first place.

Estrogen and progesterone have targets outside of the reproductive system as well. So, while estrogen is produced when a dominant follicle grows, it also maintains bone strength, supports brain function, and influences mood. And while progesterone maintains the lining of the uterus for potential pregnancy, it also influences mood and the immune system. Together, these hormones orchestrate not only reproduction but also many essential aspects of women’s overall health. So, understanding their roles is so important.

Testosterone plays a crucial role in reproduction by supporting sperm production, but its influence extends far beyond that. It helps maintain muscle mass and strength, supports bone density, regulates fat distribution, stimulates red blood cell production, and affects mood and libido. When levels of testosterone, LH, or FSH are out of balance, it can impact a man's fertility as well as overall physical and mental health.

Maybe you've been feeling unusually tired, moody, or struggling with sleep. For both men and women, these symptoms could be linked to hormone imbalances. Understanding how hormones like GnRH, AMH, FSH, LH, testosterone, estrogen, and progesterone function gives you the tools to recognize when something feels off and what steps to take next. That knowledge helps you avoid falling for the latest influencer-promoted “hormone-balancing” supplements that often lack scientific backing. Hormones operate on a delicate feedback loop, so it's important to know that taking hormone supplements without medical guidance can disrupt this balance.

Disrupting your hormone balance can lead to a cascade of problems: mood swings, anxiety, sleep issues, persistent fatigue, acne, unexplained weight gain or loss, irregular periods, low libido, infertility, and even loss of bone and muscle mass. The list goes on. In more serious cases, long-term misuse of hormone-altering products may increase risks for chronic conditions like osteoporosis, cardiovascular disease, and metabolic dysfunction.

But more than that, not knowing how your hormones work can delay diagnosis of serious underlying conditions, like PCOS, endometriosis, thyroid disorders, or low testosterone, that often go unrecognized for years. It can mean missing the signs of infertility, or ignoring symptoms that are trying to tell you something deeper is wrong. Without this knowledge, you risk normalizing pain, fatigue, or irregular cycles simply because no one ever told you how hormones work and what symptoms to look for when they are not functioning properly.

For many people, sex education didn’t include this level of detail, or perhaps it didn’t happen at all. If that’s you, you’re not alone, and more importantly, you’re not behind. Learning about your hormones now can help you make more informed decisions about your health, fertility, and overall well-being. Instead of chasing quick fixes following the most recent TikTok or Instagram supplement trend, you can track your symptoms, consult a healthcare provider, and pursue treatment that addresses the root cause. Whether you’re 13 or 35, it’s not too late to learn.

Your hormones are talking. Now you know how to listen.

Hormone Key:

GnRH (Gonadotropin-Releasing Hormone):

• Both men and women

• Released by the hypothalamus to stimulate the anterior pituitary gland to secrete LH and FSH.

AMH (Anti-Müllerian Hormone):

• Primarily women

• Helps maintain the ovarian reserve by preventing too many primordial follicles from activating at once.

FSH (Follicle-Stimulating Hormone):

• Both men and women

• In women, helps mature the egg and convert androgens into estrogens.

• In men, supports sperm production.

LH (Luteinizing Hormone):

• Both men and women

• In women, triggers ovulation and stimulates production of androgens.

• In men, stimulates production of androgens.

Estrogen:

• Primarily women

• Prepares the body for ovulation and signals the brain about follicle maturity.

Progesterone:

• Primarily women

• Produced by the corpus luteum; prepares and maintains the uterine lining for pregnancy.

Testosterone:

• Both men and women

• In women, mostly converted to estrogens.

• In men, critical for sperm production and male secondary sexual characteristics.

References:

BioRender. (2022). The Effects of GnRH and Gonadotropin Secretion. https://app.biorender.com/biorender-templates/details/t-61f808608d7ece00a46ca264-the-effects-of-gnrh-and-gonadotropin-secretion

Guttmacher Institute. (2024). Sex and HIV education. Retrieved from https://www.guttmacher.org/state-policy/explore/sex-and-hiv-education

National Conference of State Legislatures. (2020). State policies on sex education in schools. Retrieved from https://www.ncsl.org/health/state-policies-on-sex-education-in-schools

SIECUS: Sex Ed for Social Change. (2023). Mississippi State Profile. Retrieved from https://siecus.org/stateprofiles/mississippi-state-profile/