Signs Your LH Is Too High or Too Low

Luteinizing hormone, known as LH, is one of the most important signalling hormones in your reproductive system, yet it rarely gets the attention it deserves. Understanding the signs your LH is too high or too low can be the difference between years of confusion and finally having clear answers about your cycle, fertility, and overall hormonal health. LH levels meaning women need to understand goes far beyond a single blood test number. To build full context, start with The Complete Guide to Female Hormones, which covers how LH fits into the broader hormonal picture.

Whether you are dealing with irregular cycles, struggling to conceive, or navigating a PCOS diagnosis, LH is almost always part of the story. This guide breaks down what happens when this hormone swings too high or too low, what your symptoms are trying to tell you, and what you can do about it.

What Is Luteinizing Hormone and What Does It Do?

Luteinizing hormone is a pituitary hormone that triggers ovulation mid-cycle and signals the corpus luteum to produce progesterone. In women, it surges sharply around day 14 of a typical 28-day cycle, releasing a mature egg. Outside of that window, LH should remain relatively low and stable.

LH is produced by the anterior pituitary gland in response to gonadotropin-releasing hormone (GnRH) from the hypothalamus. It works in close partnership with follicle-stimulating hormone (FSH). Together, FSH and LH govern follicle development, ovulation, and the hormonal cascade that follows. When the ratio between these two hormones shifts, a high LH FSH ratio is often the first clue something is off.

LH also plays a role in stimulating androgen production in the ovarian theca cells, which is why elevated LH can sometimes drive up testosterone levels, contributing to symptoms like acne, excess hair growth, and irregular periods.

What Are the Signs Your LH Is Too High?

Signs your LH is too high include irregular or absent periods, difficulty conceiving, acne, unwanted facial or body hair, and a persistently elevated basal body temperature. A chronically high LH FSH ratio, particularly above 2:1, is a hallmark finding in polycystic ovary syndrome and can indicate disrupted ovulation signalling.

High LH is not just a number on a lab report. It produces a distinctive cluster of symptoms that can significantly affect daily life:

• Irregular or infrequent periods: When LH is chronically elevated rather than surging at the right moment, ovulation becomes unpredictable or stops altogether, throwing off your cycle length.
• Acne and oily skin: Excess LH drives ovarian androgen production, leading to the kind of hormonal breakouts that cluster around the jaw, chin, and cheeks.
• Unwanted hair growth (hirsutism): Higher androgens triggered by elevated LH can cause hair to grow on the face, chest, or abdomen.
• Infertility or difficulty conceiving: Without a well-timed LH surge, a dominant follicle may not release its egg properly.
• Multiple positive ovulation tests: Because at-home LH tests detect the surge, chronically high baseline LH can produce several positive readings across a cycle, making it hard to pinpoint true ovulation.

Research published by the National Institute of Child Health and Human Development confirms that elevated LH relative to FSH is a consistent hormonal feature in PCOS, reinforcing why the LH:FSH ratio matters clinically.

"In women with PCOS, the pulsatile release of LH is both increased in frequency and amplitude, which disrupts normal follicle development and prevents regular ovulation."

Dr. Andrea Dunaif, MD, Chief of the Hilda and J. Lester Gabrilove Division of Endocrinology, Icahn School of Medicine at Mount Sinai

What Are the Signs Your LH Is Too Low?

Low LH symptoms include absent or very light periods, failure to ovulate, low libido, fatigue, and in severe cases, bone density loss. Low LH often points to hypothalamic amenorrhoea, a condition where the brain suppresses the entire reproductive hormone cascade, commonly triggered by undereating, over-exercising, or chronic stress.

While high LH gets more attention, low LH is equally disruptive and often missed. Because LH initiates the ovulatory signal, when it is too low, the entire downstream hormonal chain goes quiet. Estrogen stays low, progesterone barely rises after ovulation (if ovulation happens at all), and the body enters a kind of reproductive hibernation mode.

Common low LH symptoms include:

• Absent periods (amenorrhoea): Without an LH surge, there is no ovulation, and without ovulation, there is no progesterone rise to trigger a bleed.
• Very light or short periods: Partial suppression of LH can mean just enough hormonal activity to produce a thin bleed but not a healthy one.
• Persistent fatigue and low mood: Low estrogen and progesterone resulting from suppressed LH can flatten energy and mood across the entire month.
• Low libido: Both estrogen and testosterone depend on adequate LH signalling; when LH drops, desire often follows.
• Bone density concerns: Chronic low LH, particularly in athletic women or those with restrictive eating, is associated with reduced bone mineral density over time.

For women who also have thyroid irregularities, it is worth knowing that thyroid dysfunction can compound LH suppression, as detailed in Your Thyroid and Cycle: The Hidden Link.

How Does the LH:FSH Ratio Help Diagnose Hormonal Problems?

The LH:FSH ratio is a diagnostic marker used to distinguish between different hormonal conditions. A high LH FSH ratio above 2:1 or 3:1 suggests PCOS, while a high FSH with relatively low LH may indicate diminished ovarian reserve or premature ovarian insufficiency. Both patterns require different approaches to treatment and support.

Getting a single LH reading in isolation tells you less than seeing how LH compares to FSH. In a typical healthy cycle, LH and FSH are relatively balanced during the follicular phase, with LH surging dramatically at ovulation before both hormones fall again in the luteal phase.

A persistently elevated LH:FSH ratio throughout the cycle rather than just at the mid-cycle surge is a key indicator flagged in PCOS assessments. According to research from a 2017 review published in Clinical Medicine Insights: Reproductive Health, an LH:FSH ratio greater than 2 or 3 measured in the early follicular phase is found in approximately 60% of women with PCOS.

Understanding this ratio is also why doctors tend to test these hormones together rather than in isolation. If you are interested in testing your hormones at home, check out How to Test Your Hormones at Home for a practical guide.

Why Do LH Levels Change Throughout Your Cycle?

LH fluctuates dramatically across a healthy cycle by design. It stays low and steady in the early follicular phase, then surges 10 to 12 times its baseline level at ovulation, before dropping back down in the luteal phase. These fluctuations are normal and necessary. Persistent highs or lows outside of this rhythm indicate a disruption in the hypothalamic-pituitary-ovarian axis.

The mid-cycle LH surge is triggered by a positive estrogen feedback loop: as the dominant follicle grows and estrogen peaks, it signals the pituitary to release a large burst of LH. This surge causes the follicle wall to rupture and release the egg, kickstarting ovulation.

After ovulation, LH drops sharply as the corpus luteum takes over progesterone production. If you have ever tracked your cycle with ovulation strips, you have witnessed this surge firsthand. The problem arises when this tightly choreographed sequence breaks down, either because LH is elevated all cycle long or because the surge never materialises at all.

"LH pulsatility is incredibly sensitive to metabolic signals. Women who are under chronic stress, over-exercising, or not eating enough will often see their LH become erratic or suppressed well before they notice any change in their cycle length."

Dr. Lara Briden, ND, Author of Period Repair Manual, Women's Health Naturopathic Doctor

How Do You Know If Your LH Is the Problem?

Knowing whether LH is at the root of your symptoms requires a timed blood test, usually done on day 2 or 3 of your cycle for baseline levels and again around day 12 to 14 to capture the surge. Tracking symptoms alongside cycle data over several months can help you and your doctor identify patterns before testing.

Symptoms alone cannot definitively tell you whether LH is too high or too low. However, the following patterns are worth investigating:

• Cycles consistently shorter than 21 days or longer than 35 days
• No detectable LH surge on ovulation strips over multiple cycles
• Multiple positive ovulation test results across several days in a row
• Unexplained infertility after six to twelve months of trying
• Signs of androgen excess alongside irregular cycles

It is also worth noting that the NICHD highlights that ovulatory disorders including those linked to LH dysregulation account for around 25% of female infertility cases, making this one of the most clinically significant hormones to monitor.

Natural Ways to Support Healthy LH Levels

Depending on whether your LH is running high or low, the supportive strategies differ, but several core lifestyle pillars benefit both ends of the spectrum.

For High LH

• Prioritise blood sugar stability: Insulin resistance drives up LH pulsatility in PCOS. Reducing refined carbohydrates and pairing carbs with protein and fat can help regulate both insulin and LH.
• Consider inositol: Myo-inositol and D-chiro inositol have strong evidence for reducing elevated LH and improving ovulatory function in PCOS.
• Reduce inflammatory foods: Chronic low-grade inflammation amplifies hormonal dysregulation. An anti-inflammatory diet supports the hypothalamic-pituitary-ovarian axis.
• Manage stress: Cortisol directly interferes with GnRH pulsatility, which in turn affects LH release patterns.

For Low LH

• Eat enough: Energy availability is the single most important factor in restoring suppressed LH. Increasing total caloric intake, particularly from carbohydrates, often restores LH pulsatility within months.
• Reduce excessive exercise: High training loads without adequate recovery suppress GnRH and therefore LH. Incorporating rest phases and lower-intensity movement helps restore the signal.
• Address chronic stress: Psychological and physiological stress both suppress hypothalamic GnRH output. Nervous system regulation practices make a measurable difference over time.
• Support thyroid function: Because the thyroid and reproductive axis are tightly linked, untreated hypothyroidism can perpetuate low LH even when other factors are addressed.