Meet Your Hormones: LH
Hormone health is like a complex puzzle, with each piece interconnected in ways that affect not just your menstrual cycle but your overall wellbeing. Understanding it is essential if you’re seeing problems crop up. Today, we're diving into Luteinising Hormone (LH), a critical yet often overlooked hormone that plays a starring role in your menstrual cycle.
What is Luteinising Hormone (LH)?
LH is a hormone produced by the pituitary gland in the brain, working closely with Follicle Stimulating Hormone (FSH). If you've been following our #MeetYourHormones series, it’ll make a lot of sense to think of FSH and LH like siblings. The production of both FSH and LH is triggered by Gonadotropin Releasing Hormone (GnRH) - both FSH and LH are gonadotropins.
Once released, LH travels from the brain to the ovaries, where it interacts with the follicles. Each follicle houses an egg, granulosa cells, and theca cells - the latter of which are crucial to LH's primary function.
The Role of LH in Your Menstrual Cycle
LH's main job is to stimulate the theca cells on the outside of the ovarian follicles. These theca cells then produce androgens, specifically testosterone and androstenedione. You might recognize these as "male" hormones, but they play an essential role in the female reproductive system as well.
These androgens aren’t the end of the story, though. They move on to the granulosa cells within the follicles, where, in the presence of aromatase (an enzyme produced thanks to FSH), they are converted into estradiol - a potent form of estrogen that dominates your reproductive years.
So, let’s summarise this process. I have highlighted the hormones in bold:
FSH + Granulosa Cells = Aromatase
LH + Theca Cells = Androgens
Androgens + Aromatase + Granulosa Cells = Estradiol (a type of estrogen)
This intricate hormonal dance shows how dependent each hormone is on the others. If one hormone is out of balance, the entire process can be disrupted, leading to menstrual cycle issues.
LH and Ovulation: The Big Event
One of LH’s most crucial roles is triggering ovulation, the moment when an egg is released from the follicle. Here’s how it works:
As your estrogen levels increase - thanks to the combined efforts of FSH and LH - your brain takes note. When estrogen reaches a peak level, the brain responds by sending a surge of both FSH and LH to the ovaries. This surge is what triggers ovulation, a key indicator of a healthy menstrual cycle.
Ovulation is not just a biological process; it’s the driving force of the menstrual cycle. When it happens smoothly, it’s a sign that your body is working in harmony.
What Happens When LH is Out of Balance?
When LH levels are either too high, too low, or out of sync with the rest of your cycle, it can cause various menstrual problems. Some common issues associated with LH imbalance include:
Missing periods: Irregular or absent periods can be a sign that LH is not being produced correctly.
Abnormal cycle length: A cycle that is shorter than 25 days or longer than 35 days might indicate LH irregularities.
Perimenopause symptoms: Fluctuations in LH can cause symptoms that normally primarily show up during perimenopause.
Estrogen levels: Since LH is crucial to estrogen production, imbalances can result in either high or low estrogen levels.
Causes of LH Disruption
Several factors can interfere with the production and release of LH, often starting with a problem in GnRH secretion:
High estrogen: While high estrogen levels are necessary at certain points in your cycle, persistent high levels can disrupt LH production.
PCOS (Polycystic Ovary Syndrome): This condition is a common cause of LH imbalance; namely, a reversed FSH to LH ratio.
High prolactin: Elevated levels of prolactin, another hormone, can inhibit LH secretion.
Hormonal birth control: This temporarily alters your natural hormone balance, affecting LH levels.
Cortisol and chronic stress: Long-term stress can wreak havoc on your hormones, including LH.
Nutritional deficiencies: Lacking essential nutrients can impair LH production.
Thyroid problems: The thyroid gland plays a crucial role in hormone regulation, including LH.
Understanding LH and its role in your menstrual cycle is a significant step toward better hormone health. While estrogen and progesterone often take center stage in discussions about reproductive health, LH is a behind-the-scenes driver that ensures everything runs smoothly. If you're experiencing menstrual irregularities, considering your LH levels - and what might be affecting them - is essential.
Stay tuned for the next installment in our #MeetYourHormones series, where we’ll dive into testosterone. If you struggle with acne, excess facial hair, irregular cycles, thinning hair, low libido, or more, this will be one you won’t want to miss.
