The ovaries release eggs and make hormones that drive puberty, periods, fertility, and the shift into menopause.
The ovaries do far more than sit beside the uterus and wait for pregnancy to happen. They are active glands with two steady jobs: they store and release eggs, and they make hormones that shape how the female reproductive system works across life.
That means the ovaries help start puberty, keep the menstrual cycle moving, prepare the body for pregnancy, and change pace with age. When people ask what the ovaries do, they’re usually asking about fertility. That’s part of the story, though not the whole thing.
To understand the ovaries clearly, it helps to think of them as both a storage site and a hormone factory. One side of their work is physical: growing and releasing eggs. The other side is chemical: making estrogen and progesterone, the hormones tied to periods, ovulation, and many body changes that show up from the teen years through menopause.
What Are The Ovaries’ Functions? In Plain Terms
The ovaries are two small glands, one on each side of the uterus. Each is about the size of an almond. Their first job is to hold a person’s lifetime supply of immature eggs. Their second job is to produce hormones that guide the menstrual cycle and reproduction.
Those two jobs work together. As an egg matures inside an ovarian follicle, the ovary also changes its hormone output. That hormone shift helps the body know where it is in the monthly cycle: before ovulation, after ovulation, or during a period.
If you want the simple version, the ovaries do four big things. They store eggs. They mature eggs. They release an egg during ovulation. And they make hormones that help regulate puberty, menstruation, fertility, and menopause.
Egg storage Starts Before Birth
Unlike sperm production, which continues through life, egg supply starts early. A female fetus forms the ovaries before birth, and those ovaries already contain immature eggs. Over time, that supply falls. By puberty, far fewer eggs remain than were present before birth.
That point matters because the ovaries are not making brand-new eggs every month. They are choosing from a fixed reserve. Across the reproductive years, some follicles begin to mature during each cycle, and one usually becomes the egg that is released.
Hormone production Runs The Cycle
The ovaries make estrogen and progesterone. Estrogen rises during the first half of the cycle as follicles grow. Progesterone becomes the main hormone after ovulation. Together, those hormones help build and shed the uterine lining, time ovulation, and prepare the body for a possible pregnancy.
These hormones also matter outside pregnancy. Estrogen is tied to breast development at puberty, menstrual timing, and broader body functions. Progesterone helps set up the uterus after ovulation and changes sharply when pregnancy does not occur, which helps trigger a period.
How The Ovaries Work During A Monthly Cycle
A monthly cycle is not just a “period issue.” It is a carefully timed sequence involving the brain, pituitary gland, ovaries, and uterus. The ovaries are central in that sequence because they respond to hormone signals and then send their own signals back.
At the start of a cycle, hormones from the brain tell a group of ovarian follicles to start maturing. As one follicle pulls ahead, estrogen rises. That rise helps prepare the body for ovulation. Mid-cycle, an egg is released. After that, the empty follicle changes form and starts producing progesterone.
If pregnancy does not happen, hormone levels drop. Then the uterine lining sheds as a menstrual period. A new cycle starts, and the ovaries begin the next round.
What Ovulation Means
Ovulation is the point where the ovary releases a mature egg. That egg enters the fallopian tube, where fertilization can happen if sperm is present. This is why ovulation sits at the center of natural fertility. No ovulation means no egg is available for fertilization in that cycle.
That does not mean the ovaries are inactive during the rest of the month. Far from it. They are active before ovulation as follicles grow, and still active after ovulation as hormone output shifts. The “release of an egg” is one moment in a longer process.
Why Periods Depend On Ovarian Signals
People often think the uterus controls periods. The uterus does the bleeding, but the ovaries help set the timing. Estrogen thickens the uterine lining. Progesterone helps stabilize it after ovulation. When those hormone levels fall, the lining breaks down and a period begins.
So if the ovaries are not ovulating well, or not making hormones in a usual pattern, the menstrual cycle can shift too. That can show up as missed periods, irregular cycles, long gaps between periods, or bleeding that feels out of step with the usual pattern.
Medical sources such as MedlinePlus on ovarian disorders describe this link clearly: the ovaries are tied to menstruation, pregnancy, and menopause, not just egg release on its own.
| Ovarian function | What the ovary does | What you notice in the body |
|---|---|---|
| Stores eggs | Holds immature eggs inside follicles | Creates the supply used across the reproductive years |
| Matures follicles | Lets selected follicles grow during each cycle | Leads toward ovulation |
| Releases an egg | Ovulates a mature egg into the fallopian tube | Creates the fertile window of the cycle |
| Makes estrogen | Produces estrogen as follicles develop | Supports puberty, cycle timing, and uterine lining growth |
| Makes progesterone | Produces progesterone after ovulation | Helps prepare the uterus for pregnancy |
| Helps regulate periods | Changes hormone levels across the month | Shapes when bleeding starts and stops |
| Supports fertility | Provides the egg needed for fertilization | Affects the chance of natural conception |
| Drives life-stage changes | Shifts hormone output from puberty to menopause | Affects breast development, cycle changes, and menopause timing |
Taking A Closer Look At Ovaries And Their Main Jobs
They Help Start Puberty
Before puberty, ovarian hormone levels stay low. As puberty begins, signals from the brain tell the ovaries to increase hormone production. Estrogen helps trigger breast development and the start of menstruation. That is one of the clearest signs that the ovaries are active long before anyone is trying to conceive.
Puberty is not a one-day switch. It is a staged process, and the ovaries are woven through it. As hormone output rises, the body starts cycling toward regular ovulation and menstruation, though early cycles are often irregular.
They Support Fertility
Fertility depends on more than healthy ovaries, though the ovaries are a big part of the picture. They must mature and release an egg. They also need to produce the hormonal pattern that lines up ovulation with the uterine changes needed for pregnancy.
The NHS explanation of fertility in the menstrual cycle lays out this sequence in simple terms: rising estrogen helps the ovary develop and release an egg, then progesterone helps prepare the womb lining after ovulation.
When ovulation does not happen, natural conception in that cycle cannot happen either. That is why conditions that affect ovulation, such as polycystic ovary syndrome, can affect fertility.
They Shift With Age
The ovaries do not work the same way at 13, 28, and 52. Across time, egg supply shrinks and hormone patterns change. Cycles may stay regular for years, then become less predictable as menopause gets closer.
Menopause marks the point when ovarian function has changed enough that periods stop for good. The ovaries release eggs less often, then stop. Estrogen and progesterone levels also fall. That is why menopause is not only about the end of periods. It reflects a major change in ovarian activity.
The sequence of follicle growth, ovulation, and progesterone production is also described by NICHD’s ovulation overview, which traces how brain signals and ovarian hormones work together during a cycle.
What Happens When Ovarian Function Changes
Because the ovaries affect so many parts of reproduction, problems can show up in different ways. Some people notice irregular periods. Some have trouble getting pregnant. Some notice pelvic pain or hormone-related symptoms. The pattern depends on what part of ovarian function has changed.
Irregular ovulation
If the ovaries do not release eggs on a regular schedule, periods may become erratic. You might see long cycles, skipped months, or bleeding that feels hard to predict. This can happen in the teen years, around menopause, or with conditions that disrupt ovulation.
Hormone imbalance
When ovarian hormone output shifts, the body notices. Estrogen and progesterone are tied to cycle timing and reproductive function, so changes can show up as missed periods, fertility issues, or cycle-related symptoms that feel different from the usual pattern.
Ovarian cysts And Related Conditions
Some cysts form as part of normal ovulation and often pass on their own. Other ovarian conditions are less simple and may need medical care. A cyst, pain, or irregular cycle does not always mean a major problem, though ongoing symptoms deserve proper assessment.
| Life stage | What the ovaries are mainly doing | Typical effect |
|---|---|---|
| Before puberty | Holding immature eggs, low hormone output | No menstrual cycles yet |
| Puberty | Increasing estrogen production, starting ovulation patterns | Breast development and first periods |
| Reproductive years | Maturing follicles, ovulating, making estrogen and progesterone | Regular cycles and fertility potential |
| Perimenopause | Less predictable ovulation and hormone output | Irregular periods and cycle changes |
| After menopause | Egg release ends and hormone levels stay low | Periods stop |
Why Understanding Ovarian Function Matters
Knowing what the ovaries do helps make sense of many common questions. Why did periods start? Why did they change? Why does ovulation matter so much for pregnancy? Why do symptoms shift near menopause? The same organs sit behind all of those questions.
It also clears up a common mistake. The ovaries are not only “egg holders.” They are hormone-making glands with a month-by-month role in the cycle. Without that hormone output, menstruation, ovulation timing, and preparation for pregnancy would not work in the same way.
So when someone asks, “What Are The Ovaries’ Functions?” the full answer is this: the ovaries store and release eggs, make estrogen and progesterone, regulate ovulation and periods, support fertility, and change their output across life from puberty to menopause.
That’s why these small glands carry so much weight in reproductive health. They set the pace, send hormonal signals, and shape the body’s monthly rhythm for years.
References & Sources
- MedlinePlus.“Ovarian Disorders.”Explains that the ovaries make eggs and hormones and are involved in menstruation, pregnancy, and menopause.
- NHS.“Periods and Fertility in the Menstrual Cycle.”Describes how estrogen and progesterone work with ovulation and the uterine lining during the menstrual cycle.
- NICHD.“Women’s Health Infographic: Ovulation (Text Alternative).”Outlines the hormone signals behind follicle growth, egg release, and progesterone production after ovulation.