Written by: Dr. Amy Beckley, PhD, Founder and Inventor of the Proov test — the first and only FDA-cleared test to check for successful ovulation at home.
Written on: 3/23/22
FSH, what is that? Keep scrolling to learn more about the hormone!
Over the years, hormones change drastically – we go through different stages of our lives and these hormones adapt and morph with us. Since hormones have such a large impact on our bodies – from changes in moods to physical differences – it’s super important to test your hormone levels.
There are four key cycle hormones: estrogen, progesterone, LH, and FSH. Today we’re going to do a deep dive into FSH, otherwise known as the follicle stimulating hormone. Keep scrolling down to learn all about this important hormone!
What is FSH?
First let’s get into the basics: what is FSH? FSH, or follicle stimulating hormone has a pretty descriptive name – it stimulates the ovaries to grow and mature follicles in preparation for ovulation.
These follicles then develop until one is mature enough to release an egg. This all happens during the first phase of your cycle called the follicular phase. The whole process is essential to helping control a woman’s cycle and ovulation.
FSH starts to rise at the very beginning of your cycle in preparation for ovulation. After the ovaries are stimulated and one follicle becomes dominant – meaning it will eventually release the egg that cycle – it becomes FSH independent. It no longer needs the hormone because it’s mature and ready for ovulation.
FSH starts to rise at the beginning of your cycle since it is the hormone that helps your ovaries to grow and mature follicles.
What are FSH levels and why are they important?
When there are many follicles and eggs left in the body, the ovaries don't need as much FSH to stimulate them. While small amounts of FSH indicates many eggs left, high FSH levels may be a sign of less eggs.
Since women are born with all the eggs they’ll ever have, and at least 1 egg is typically released each cycle, this inherently means that with age we have less eggs. Another term used for the amount of eggs one has left is ovarian reserve. As this reserve diminishes your ovaries stop working as well, meaning that each cycle higher levels of FSH are needed to stimulate the ovary.
A second way to determine your ovarian reserve is to test your AMH. Testing your AMH, or Anti-Mullerian Hormone, is an equally as accurate test to your FSH. However, FSH can be done at a 5th of the cost, and can be determined through urine instead of blood.
FSH levels are important for any woman to be aware of – understanding this hormone gives you a sign of how many eggs you have left. This can help you understand how close you are to menopause, or about how long you have left to conceive. It is important to note that high levels of FSH do not necessarily mean that you cannot conceive, but it can mean you may have less ovulations left than someone with lower FSH levels.
FSH levels also matter if you are planning to use assisted reproductive technology such as in vitro fertilization. If you have high levels of FSH, aka a diminished ovarian reserve, it may mean that you will not respond as well to these medications which means it would affect the success rate of IVF.
What are FSH levels during perimenopause?
As we get older (think 35 and up), our ovarian reserve naturally diminishes; this is totally normal for everyone with ovaries! An increase in FSH (signaling a lower ovarian reserve) may be a sign that you are approaching perimenopause. Not to be confused with menopause, perimenopause is the transitional period before you stop having a period altogether.
Some women, however, may experience diminished ovarian reserve (DOR) at an earlier age. For some, this may occur as early as their 20s – this is then called primary ovarian failure.
While both perimenopause and primary ovarian failure (POF) both could cause high levels of FSH, there are different symptoms of each.
Some symptoms of perimenopause include:
- Irregular periods or skipping periods
- Hot flashes
- Vaginal dryness and discomfort during sex
- Urinary urgency
- Sleep problems
- Mood swings
Some symptoms of primary ovarian failure include:
- Absence of menstruation
- Pain during intercourse
- Decreased sexual desire
- Dry eyes
- Hot flashes
- Difficulty getting pregnant
During perimenopause, FSH levels typically range from about 16-24 mIU/ml. For context, FSH levels before 35 should ideally be below 10.
It is not uncommon to observe FSH levels in the higher range - 16 - 24 mIU/ml in the late 30s through late 40s. Levels this high typically mean you are experiencing perimenopause and that may be accompanied by some of the symptoms listed above.
What are FSH levels during menopause?
Menopause is a bit different than perimenopause; the average age for women to go through menopause is at 51 years old. The clinical definition of Menopause is when a woman has gone 12 months without a period.
Once you stop ovulating, then your body is “in menopause.” During this time, your FSH levels are typically even higher than perimenopausal levels. As mentioned earlier, the higher your FSH levels get, the closer you are to menopause.
Typically, women with FSH levels of 25 and higher means that you are in menopause. This means that you have depleted your ovarian reserve – which is totally normal as we age.
In order to gain all this insight, you’ll need to test your FSH levels. But how does one do that? Enter Proov Reserve – with this test you are able to learn all about your ovarian reserve!
Test your FSH levels with Proov Reserve!
You can understand all of these levels at home by testing your FSH with Proov Reserve! To understand your FSH levels is empowering. If you’re actively trying to conceive, wondering when you can have kids in the future, or thinking about when perimenopause might begin, FSH tests can help reveal all these secrets. Proov Reserve allows you to keep track of your FSH levels without having to take a blood test, too.
In order to get the most accurate results, you’ll need to download the Proov Insight App. With the app, you’re able to know exactly what days to test on, get clear, actionable results, and can track your levels cycle to cycle. FSH is essential for planning ahead – by knowing your levels you can set yourself up for success during any transition that life might throw at you.