Hello! My name is Tori and I am a doctor of physical therapy who
specializes in pelvic dysfunction, which means
I treat things that can go wrong around the pelvis—and this includes sexual dysfunction.
If you haven’t, be sure to check out the very first video in this series as it introduces
what’s normal and abnormal around female sex drive and speaks more about my intention
behind creating this series—which is, essentially, to walk you through
how I would approach healing low libido as a patient who is also a pelvic health provider.
Today, we’ll be discussing hormones and female low libido. Now, this is a dense and complicated
topic, and I want you to walk away from this video with a solid understanding of how the female sex
hormones might affect female libido, and how to best interpret the results of a hormone level
test. However, in order to fully understand those topics, you need a general understanding of what
hormones are and how they function, as well as a more specific understanding of what the female
sex hormones are, how they function, and how they fluctuate naturally in throughout your lifetime.
This video is going to focus on building the necessary background knowledge,
so that the next video in this series can jump right in to how the female sex hormones might
affect libido, and how to interpret the results of a hormone level test.
Of course, you can check the description below for timestamps if you want to skip around,
as well as links to any studies or resources mentioned in the video.
So, before we start unpacking the female sex hormones,
I want to be sure you understand what hormones are and how they function in our bodies.
Science likes to compartmentalize the human body into different systems,
and today we’re investigating both the female reproductive system and hormones,
which are a part of the endocrine system. You might naturally be more familiar with the female
reproductive system—which we can simplify to the external vulva, which includes the vaginal lips,
vaginal opening, and clitoris—and the internal vagina, cervix, uterus, fallopian tubes,
and ovaries. If you feel like you need to brush up on your knowledge
of the female reproductive system, check out my video about getting pregnant on
your period, there is an extensive review of the female reproductive system there.
The endocrine system, on the other hand, is made up of a collection of organs—known
as endocrine glands—that regulate different bodily functions—such as
metabolism, appetite, heart rate, blood pressure, body temperature, sleep, growth,
AND sexual function—by secreting hormones into the bloodstream. Let’s break that down a little more.
First of all, know that an organ is called a gland when it makes and releases a substance
that performs a specific action in the body. A gland you might be more familiar with is a
sweat gland—it makes sweat and releases it onto your skin, which keeps you cool. In the case of
the endocrine system, endocrine glands make hormones, release those hormones into the
bloodstream, and the hormones tell different parts of the body to perform an array of actions. These
endocrine glands are located in your brain, your neck, your torso, your abdomen, and your pelvis.
Second of all, it helps to think of hormones as chemical messengers and the bloodstream as
those messengers’ means of travel. An example you may be very familiar with is an adrenaline rush.
Think about the last time you watched a scary movie or performed a scary activity
like zip-lining or bungee jumping. You might remember sweating, feeling your heart rate
increase, your breathing get faster, or maybe getting a big boost of energy. This is because
your brain signaled to the endocrine glands in your abdomen—known as your adrenal glands,
they live on top of your kidneys—to produce a hormone—adrenaline—and
release that hormone into your bloodstream so that it can travel to different parts of your
body and tell that body tissue what to do. In this scenario,
adrenaline will travel to the muscles below your skin, to stimulate sweating, your heart,
to tell the cells to beat faster, your lungs, to tell the muscles to get your body more oxygen, and
to your liver, to tell your liver cells to break down sugar and give your body a boost of energy.
So, in summary, the endocrine system is made up of a collection of organs—known
as endocrine glands—that produce hormones—or chemical messengers—and release those hormones
into the bloodstream, so that they can travel to different parts of the body and tell those
parts of the body what to do in order to regulate different bodily functions—including
sexual function. That’s why, when you get your hormone levels tested, it’s a blood test!
Now that we’ve talked about a general overview of hormones and the endocrine system,
let’s zoom into the sex hormones and endocrine glands responsible for female sexual function.
Female sex hormones include estrogen, progesterone, and small amounts of testosterone.
The organs or endocrine glands that produce and secrete these sex hormones are the ovaries
and the adrenal glands. Recall that the ovaries are also a part of the female reproductive system,
and are located in the pelvis, connecting to the uterus via our fallopian tubes. The adrenal glands
are the endocrine glands we talked about in our adrenaline rush example earlier,
and they are located in your abdomen, on top of your kidneys. Both the ovaries and the adrenal
glands produce and release all three types of sex hormones—estrogen, progesterone, and testosterone.
Now, estrogen, progesterone, and testosterone all affect female libido—but they also play important
roles in a range of bodily functions, including: puberty, reproduction, body fat distribution,
hair growth, bone and muscle growth, cholesterol regulation, and inflammation. That means the sex
hormones naturally fluctuate in our bodies throughout our our lifetimes.
In order to understand how these sex hormones might affect female libido and how to
interpret the results of a hormone level test, you need to be aware of these natural fluctuations.
So, some factors that may affect the levels of female sex hormones present
in someone’s body include: puberty, menstruation, pregnancy, breastfeeding,
perimenopause, and menopause—which means age is a factor. Know that
stress and medication can also affect hormone levels—we’re going to focus on the fluctuations
associated with age in this video, but if you want to learn more about stress,
I’ll be creating a video dedicated to lifestyle and low libido in women, and if you want to learn
more about medications, that video already exists in the series and you can click here to watch it.
Let’s examine each of these factors briefly. During puberty, all of the sex hormones naturally
increase, especially estrogen—this stimulates breast development, pubic and armpit hair growth,
an increase in body fat, the maturation of the female reproductive organs, and the start
of menstruation—or your period. So, we would expect a young girl going through puberty to
demonstrate elevated levels of all of her sex hormones, especially estrogen.
During your menstrual cycle, all of the sex hormones
rise and fall in a pattern. Now, there is great variation in every woman’s cycle.
However, strictly for simplicity’s sake, let’s look at a 4 week or 28 day cycle, where someone
ovulates on day 14. Recall that day 1 of your cycle is the first day you start to bleed,
and the last day of your cycle—day 28 in our example—is the day before your next period begins.
Also recall that, generally speaking, there are three main phases of your menstrual cycle:
the follicular phase, the ovulatory phase, and the luteal phase. The follicular phase
can be simplified to the first 14 days of a 28 day cycle. During this phase,
your uterus sheds its lining, aka you have your period, and the ovaries start to grow follicles,
which contain eggs—hence the “follicular” phase. The ovulatory phase begins when the
dominant follicle ruptures and releases its egg—aka when you begin to ovulate. This phase
might last half a day to a day a half. Finally, the luteal phase begins after ovulation. The
ruptured follicle closes, and the uterus thickens in preparation for a fertilized egg.
If that doesn’t happen, the uterus sheds its lining, and the follicular phase begins again.
Now, let’s look at the sex hormones and how they’re fluctuating during a
woman’s menstrual cycle. Estrogen will peak twice during your cycle, once leading up to ovulation,
then again in preparation for your uterus to receive a fertilized egg. If that doesn’t happen,
it will steadily decline again. Progesterone really peaks once during your cycle,
and that’s in tandem with estrogen’s second peak in preparation for your uterus to receive
a fertilized egg. If that doesn’t happen, it will steadily decline again. Finally,
testosterone slowly but steadily rises during your follicular phase, peaks in tandem with estrogen’s
first peak during ovulation, and then slowly but steadily decreases during your luteal phase.
So, we would expect a woman of reproductive age who is not pregnant to have higher
and lower levels of all three sex hormones circulating in her system pending on where
she is in her menstrual cycle. This could be one way for us to study how sex hormones might affect
female libido, and this must be taken into consideration when interpreting the results
of a hormone level test. Of course, if you are taking hormonal birth control, these fluctuations
will be different. I don’t have the time in this video to explore every example of how different
hormonal birth controls can alter the level of sex hormones in your body—but I do encourage you to:
be aware that this is the case research the specific kind
of birth control that you’re taking and learn how it might affect your hormone
levels, so that you are better able to read and interpret the results of your hormone level test
During pregnancy, both estrogen and progesterone steadily rise as the fetus develops. We would
expect a pregnant woman in her third trimester to have higher levels of estrogen and progesterone
than a woman in her second trimester, and a woman in her second trimester to have higher levels
of these hormones than a woman in her first trimester. We would also expect any pregnant
woman in any trimester to have higher levels of estrogen and progesterone than a non-pregnant
woman. We’ve also found that testosterone steadily increases during pregnancy, but we
think how much of an increase we see may depend on the sex of the fetus. Regardless, we’d also
expect a pregnant woman to have higher levels of testosterone than a non-pregnant woman.
After delivery, estrogen levels drop and stay low until a woman is done breastfeeding.
Progesterone levels also drop, and will not return to normal until a woman ovulates again.
Finally, testosterone levels are also lower in breastfeeding women. So,
we would expect a postpartum, breastfeeding woman who has
not gotten her period back yet to have low levels of all three sex hormones.
During perimenopause and menopause,
estrogen and progesterone both decline. During perimenopause—the
period of time leading up to menopause—estrogen levels tend to fluctuate while progesterone
steadily declines. This is because your ovaries start producing less hormones. As estrogen levels
fluctuate and progesterone decreases, you might notice vaginal dryness, irregular periods,
mood changes, hot flashes, and difficulty sleeping. A person officially reaches menopause
when they’ve gone a full 12 months without a period. After menopause, your ovaries will still
constantly produce estrogen and progesterone, but only very small amounts. The decline in
testosterone in women, on the other hand, is solely age-related, not menopause-related,
and begins years before perimenopause. Levels peak in a woman’s 20s and decline slowly thereafter.
By menopause, testosterone levels are usually around half of what they were at their peak.
This is because your ovaries and adrenal glands continue to make testosterone
even after estrogen and progesterone production lowers during menopause. So, we would expect
a perimenopausal woman to have unpredictable levels of estrogen, lower levels of progesterone,
and testosterone levels that match her age. And, we’d expect a menopausal woman to have steady low
levels of estrogen and progesterone, and testosterone levels that match her age.
Now that you have a general knowledge of what hormones are and how they function in our bodies,
as well as what the female sex hormones are, how they function, and how they naturally fluctuate in
our bodies, we can focus on the two big questions: How do estrogen, progesterone, and testosterone
affect female libido? And, how do I best interpret the results of my hormone level test?
And that’s exactly where we’ll pick up in the next installation in this series! On that note,
thank you so much for watching! I’m approaching this series differently than any other content
I’ve created before, so please let me know what you think of this style. I’m very open to any
and all of your feedback. So, if you liked this video or found it helpful, please give it up a
thumbs up. If you didn’t like it, please give it a thumbs down. Feel free to comment feedback,
questions, requests, anything down below—I do try really hard to read and respond to
all of my comments. Don’t forget to check meowt on instagram and finally, if you want to,
please subscribe to my channel for more content not only about pelvic things but also about life
things. I hope you have a wonderful rest of your day and I will see you in the next video. Bye!