Follicular Phase: What It Is and How it Impacts You

What is the Follicular phase?

The follicular phase consists of different stages in your menstrual cycle where the follicle (egg) matures.

It is the largest part of your menstrual cycle, which starts with your period and ends when you ovulate.

Your menstrual cycle is a combination of 4 Major stages: Menstruation, the follicular phase, ovulation, and the luteal phase.

Menstruation (also known as the early follicular phase)

Menstruation is when you shed the uterine lining for 3 to 7 days. The uterine lining builds up during the luteal phase, which is right before the follicular phase.

At this stage, your hormone levels are low.

The follicular phase

The mid-follicular phase is where the follicle (egg) forms which causes oestrogen to increase in your body which leads to ovulation. The higher levels of oestrogen lead to the uterus producing a thick lining for the egg to implant there.

At this part of the cycle, the egg reaches full maturity. Your oestrogen levels start to increase.

Ovulation (also known as the late follicular phase)

Ovulation is the release of the egg to be fertilised. If this doesn’t happen, the egg is released in menstruation.

Your oestrogen levels drop and your progesterone levels start to rise. Your energy levels are at their peak where you feel most confident.

Luteal phase

The luteal phase is after ovulation and before menstruation. The released egg from ovulation changes the structure that holds the egg into the corpus luteum.

The corpus luteum starts to produce progesterone which helps thicken the uterine lining. If the egg isn’t fertilised, the corpus luteum stops producing progesterone and releases the uterine lining which starts menstruation.

What happens to hormones during the follicular phase?

In the follicular phase, oestrogen increases after menstruation. The higher oestrogen levels result in ovulation occurring.

The oestrogen levels increase between the end of your period to ovulation. Oestrogen levels drop immediately after ovulation.

How will I feel during the Follicular phase?

Your energy level during the follicular phase will rise from the previous phase (luteal phase). Your energy levels are at their highest.

Physical strength is higher and you have more confidence. You’re also more likely to make plans and socialise more.

What is the normal duration of the follicular phase?

The follicular phase can last between 12 to 18 days which can change between cycles. Its length depends on how long it would take for the egg to mature based on your oestrogen levels. The size of the phase changes for every woman. It can also change per cycle. Sometimes the length can be affected by a vitamin D deficiency and birth control.

When is the follicular phase considered short?

A study was done in 2010 which stated that a follicular phase can be considered short when it falls below 11 days. A shorter follicular phase could impact your likelihood of getting pregnant.

Depending on your age, it could be an indicator that you’re through menopause. In your late 30s, you will start to experience shorter follicular phases because your eggs are maturing faster from FSH not being able to reach the same levels as it used to.

Therefore, the eggs may not be able to be fertilised which is the start of menopause.

When is the follicular phase considered long?

According to a study in 2010, a long follicular phase is 18 days or longer.

The length of the phase changes from woman to woman, therefore, it might be normal for you to have a long follicular phase but to someone else, it may not be.

A longer follicular phase can be caused by a vitamin D deficiency or birth control.

What are the symptoms in the follicular phase?

The main symptoms you can experience during your follicular phase are:

Physical symptoms

• More energy
• High sex drive
• Clearer skin
• More able to lift heavy items

Mental symptoms

• Socialising capability
• Increased confidence
• More likely to make plans and take risks

Do I bleed during the follicular phase?

In the early follicular phase (menstruation) you bleed your uterine lining. This lasts between 3 to 7 days depending on the cycle.

There could be heavy or light flow which depends on the person.

Can you get pregnant during the follicular phase?

During the late follicular phase (ovulation) is the ideal time to become pregnant. In the late follicular phase, the follicle is maturing to be released for fertilisation. Therefore, if intercourse happens during this phase, it is more likely for you to become pregnant.

What is the body temperature during the follicular phase?

The study “Temperature regulation in women: Effects of the menstrual cycle” showed women experience a change in core body temperature throughout their menstrual cycle, with body temperature rising during the luteal phase, post-ovulation.

As such, during the follicular phase, a woman’s body temperature is l0.3-0.7 degrees celsius lower than during the Luteal phase.

This temperature change can be used to track ovulation and is influenced by hormones, but there is still much to learn about the mechanisms behind it your core body temperature is lower in the follicular phase than the luteal phase.

References

• NCIB (2022) - Physiology, Menstrual Cycle
• PubMed (2020) - Temperature regulation in women: Effects of the Menstrual Cycle
• PubMed (2010) - Life-Style and Reproductive Factors Associated with Follicular Phase Length
• National library of medicine (2022) - Menstrual Cycle Proliferative and Follicular Phase
• National library of medicine (2015) - Progesterone and Luteal Phase