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What You Need To Know About The Follicular Phase Of Your Menstrual Cycle

Anna Cabeca, D.O.
October 28, 2021
Anna Cabeca, D.O.
Triple board certified OB/GYN
By Anna Cabeca, D.O.
Triple board certified OB/GYN
Dr. Anna Cabeca is a menopause and sexual health expert currently working in Georgia. She received her doctor of osteopathic medicine in gynecology and obstetrics from the Emory University School of Medicine.
October 28, 2021

A woman's menstrual cycle, though often associated with PMS, cravings, and cramps, doesn't have to have such an impact. If you learn to understand what's happening to your hormones during each phase, you can better optimize the cycle—and given this process occurs every month for a woman's reproductive life, coming to understand it is pretty important.

Medically, we refer to four phases of the menstrual cycle: menstruation, follicular phase, ovulation, and luteal phase. But we can technically divide it into just two phases: the follicular phase and the luteal phase.  

What is the follicular phase?

The beginning of the follicular phase happens during menstruation, when there is an elevation in follicle-stimulating hormone (FSH), and ends with ovulation.

To better understand this process, it is important to know the following: a female baby is born with approximately one million eggs. By the time they reach reproductive age and start menstruation, they only have about 300,000 eggs left and will ovulate 400 to 600 times in a reproductive lifespan. Of that original one million, just 11 to 20 primary oocytes (or immature eggs) will begin to develop in the follicular phase—this maturation process is triggered by the follicle-stimulating hormone.

What happens during the follicular phase?

During the follicular phase, the brain signals the release of the FSH, which releases fluid-filled sacs called follicles, containing immature eggs. When estrogen levels increase, the blood vessel supply also increases, and the inside lining of the uterus starts to thicken.

Approximately 11 to 20 follicles develop during this follicular phase. During this development, one oocyte will become more dominant than the rest and will eventually be released—that is precisely when someone can become pregnant.

There's also an increase in the luteinizing hormone (LH), which slightly peaks at the end of the follicular phase. This occurs directly before ovulation and is what stimulates the release of the mature egg.

What are the symptoms of the follicular phase?

Symptoms of the follicular phase usually include an increase in energy, clarity, and a fairly warm body temperature from 97 to 97.5 at basal (meaning the temperature you are first thing in the morning, before you even get out of bed).

How long is the follicular phase, normally?

The follicular phase can last anywhere from 11 to 27 days, beginning with menstruation and ending with ovulation. While there's no such thing as a "normal" menstrual cycle, the average time people spend in the follicular phase seems to be about 16 days1.

What it may mean if yours is longer/shorter?

Ordinarily, if your follicular phase is shorter, it means an earlier ovulation. If it's longer, it usually means, anovulation, meaning that you did not ovulate that month or your body is taking longer to ovulate (i.e., release a mature egg).

How to lengthen the follicular phase.

Longer follicular phases have been tied to vitamin D deficiency2, but it can also be a sign of estrogen deficiency, exposure to endocrine disrupters, or a history of birth control pills3.

Can you get pregnant during the follicular phase?

If you have intercourse toward the end of the follicular phase, make no mistake: You can still get pregnant! The sperm will last into the luteal phase (in fact, it typically lasts three days, or 72 hours), meaning it can remain potent even after ovulation.

How to optimize for the follicular phase.

What to eat

Eating healthy fats, high-quality protein, and lots of dark green, leafy vegetables is really important to nourish your body. Plus, eating these digestion-supporting foods can help you metabolize estrogen more efficiently. If possible, I also recommend buying organic food to eliminate exposure to unwanted pesticides. Find out what to eat during every phase, here.

What type of workout to do

At the end of the follicular phase, when your LH is peaking, you will also have a peak in testosterone. Therefore, it can be helpful to do more high-intensity interval training and lift heavier weights during this time.

What to avoid

Avoiding endocrine disrupters is important for keeping your hormone levels (particularly estrogen) functioning optimally. This can include plastic water bottles, food with pesticides, certain chemical-containing makeup products, cleaning supplies, or detergents, etc.

And of course, as I always say, limit refined sugars and processed foods, and if you eat cheese or butter, opt for the organic options from grass-fed cows.

Other things to keep in mind

While maintaining the well-being of our ovaries starts in our youth, it is never too late to move the odds in your favor by supporting your body with a healthy diet and workout routine. It is important, not only to have a smooth and easy menstrual cycle, reducing discomfort associated with PMS, but also to sail through menopause without too many symptoms. 

Eliminating exposure to endocrine-disrupting chemicals to the best of your ability, upping vitamin D levels, improving your exercise regimen, and managing your stress level can help significantly in regulating the follicular phase.

Anna Cabeca, D.O. author page.
Anna Cabeca, D.O.
Triple board certified OB/GYN

Dr. Anna Cabeca is a menopause and sexual health expert currently working in Georgia. She received her doctor of osteopathic medicine in gynecology and obstetrics from the Emory University School of Medicine. Cabeca is the creator of many products for hormone and dietary support and is the author of The Hormone Fix, a comprehensive diet and lifestyle plan for women approaching or in menopause. She has been featured on NBC, CBS, and ABC and in the Huffington Post and Reader's Digest.