Luteinising Hormone
Luteinising Hormone
Luteinising hormone (LH) stimulates ovulation in women and testosterone production in men.
Luteinising hormone (LH) stimulates ovulation in women and testosterone production in men.
Luteinising Hormone
Normal range
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Luteinising Hormone
Luteinising Hormone
Luteinising hormone (LH) stimulates ovulation in women and testosterone production in men.
Luteinising Hormone
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Luteinising Hormone
Luteinising Hormone
Luteinising hormone (LH) stimulates ovulation in women and testosterone production in men.
Luteinising Hormone
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Male: 1.7-8.6 Female: 1-95.6 IU/L
Male: 1.7-8.6 Female: 1-95.6 IU/L
Normal range
Luteinising Hormone
Dr. Thiviya Sivakanthan
MBBS
Your Body's Ovulation Trigger
Your Body's Ovulation Trigger
Every month, your body relies on a crucial hormone that acts like a precise timing mechanism, orchestrating ovulation and hormone production with split-second accuracy—luteinising hormone (LH). When this hormone isn't working properly, it can disrupt your entire reproductive cycle, leaving you with irregular periods, fertility problems, or confusing symptoms that seem to come from nowhere.
LH is like your reproductive system's master timekeeper, sending perfectly timed signals that trigger ovulation and coordinate other essential hormones. Think of it as nature's ovulation alarm clock—when LH levels surge at just the right moment, your reproductive system works like clockwork, but when the timing goes wrong, your fertility and menstrual health can suffer dramatically.
Every month, your body relies on a crucial hormone that acts like a precise timing mechanism, orchestrating ovulation and hormone production with split-second accuracy—luteinising hormone (LH). When this hormone isn't working properly, it can disrupt your entire reproductive cycle, leaving you with irregular periods, fertility problems, or confusing symptoms that seem to come from nowhere.
LH is like your reproductive system's master timekeeper, sending perfectly timed signals that trigger ovulation and coordinate other essential hormones. Think of it as nature's ovulation alarm clock—when LH levels surge at just the right moment, your reproductive system works like clockwork, but when the timing goes wrong, your fertility and menstrual health can suffer dramatically.
The LH Surge: Your Monthly Fertility Window
The LH Surge: Your Monthly Fertility Window
The LH Surge: Your Monthly Fertility Window
Discover how this hormone creates your most fertile days and why timing is everything for conception.
Read more
When LH Levels Signal Trouble
When LH Levels Signal Trouble
When LH Levels Signal Trouble
Learn why irregular LH patterns might be the hidden cause behind your fertility struggles or period problems.
Read more
What Disrupts Your LH Production
What Disrupts Your LH Production
What Disrupts Your LH Production
From stress to medical conditions, understand what can throw off your body's delicate ovulation timing.
Read more
Understanding Your Results
Understanding Your Results
Understanding Your Results
Decode your hormone numbers and understand what your LH levels reveal about your reproductive health.
Read more
The LH Surge: Your Monthly Fertility Window
The Ovulation Countdown: Your LH surge is like a precisely timed rocket launch that happens once each cycle. Throughout most of your cycle, LH levels remain relatively low, quietly monitoring your hormone levels like a patient sentinel. But when conditions are perfect—when oestradiol levels peak and your body is ready for ovulation—LH levels spike dramatically, sometimes increasing by 300-400% within just 24-48 hours.
This surge is nature's way of creating your fertility window. It's like your body's internal countdown timer that's been monitoring hormone levels and waiting for the perfect chemical signal to release the egg. The LH surge doesn't just cause ovulation—it also transforms the empty follicle into the corpus luteum, which produces progesterone to support early pregnancy.
The Timing Challenge: The LH surge is remarkably brief, lasting only 12-36 hours, which is why timing is everything when trying to conceive. It's like trying to catch a shooting star—you need to be looking at exactly the right moment. This short window explains why some women struggle to detect their LH surge with home ovulation tests, particularly if they have irregular cycles or test at the wrong times.
For men, LH works differently but equally importantly, providing steady stimulation to the cells in the testes called Leydig cells to produce testosterone. Unlike the dramatic monthly surges women experience, men rely on consistent LH levels to maintain hormone production and fertility throughout their lives.
The LH Surge: Your Monthly Fertility Window
The Ovulation Countdown: Your LH surge is like a precisely timed rocket launch that happens once each cycle. Throughout most of your cycle, LH levels remain relatively low, quietly monitoring your hormone levels like a patient sentinel. But when conditions are perfect—when oestradiol levels peak and your body is ready for ovulation—LH levels spike dramatically, sometimes increasing by 300-400% within just 24-48 hours.
This surge is nature's way of creating your fertility window. It's like your body's internal countdown timer that's been monitoring hormone levels and waiting for the perfect chemical signal to release the egg. The LH surge doesn't just cause ovulation—it also transforms the empty follicle into the corpus luteum, which produces progesterone to support early pregnancy.
The Timing Challenge: The LH surge is remarkably brief, lasting only 12-36 hours, which is why timing is everything when trying to conceive. It's like trying to catch a shooting star—you need to be looking at exactly the right moment. This short window explains why some women struggle to detect their LH surge with home ovulation tests, particularly if they have irregular cycles or test at the wrong times.
For men, LH works differently but equally importantly, providing steady stimulation to the cells in the testes called Leydig cells to produce testosterone. Unlike the dramatic monthly surges women experience, men rely on consistent LH levels to maintain hormone production and fertility throughout their lives.
The LH Surge: Your Monthly Fertility Window
The Ovulation Countdown: Your LH surge is like a precisely timed rocket launch that happens once each cycle. Throughout most of your cycle, LH levels remain relatively low, quietly monitoring your hormone levels like a patient sentinel. But when conditions are perfect—when oestradiol levels peak and your body is ready for ovulation—LH levels spike dramatically, sometimes increasing by 300-400% within just 24-48 hours.
This surge is nature's way of creating your fertility window. It's like your body's internal countdown timer that's been monitoring hormone levels and waiting for the perfect chemical signal to release the egg. The LH surge doesn't just cause ovulation—it also transforms the empty follicle into the corpus luteum, which produces progesterone to support early pregnancy.
The Timing Challenge: The LH surge is remarkably brief, lasting only 12-36 hours, which is why timing is everything when trying to conceive. It's like trying to catch a shooting star—you need to be looking at exactly the right moment. This short window explains why some women struggle to detect their LH surge with home ovulation tests, particularly if they have irregular cycles or test at the wrong times.
For men, LH works differently but equally importantly, providing steady stimulation to the cells in the testes called Leydig cells to produce testosterone. Unlike the dramatic monthly surges women experience, men rely on consistent LH levels to maintain hormone production and fertility throughout their lives.
When LH Levels Signal Trouble
Irregular LH Patterns: When LH levels don't follow their normal pattern, it's like having a faulty alarm clock that either doesn't ring or rings at the wrong time. You might experience irregular periods, with cycles that are much longer or shorter than normal, or you might skip periods entirely. This disruption often indicates that ovulation isn't occurring regularly or at all.
Some women have LH levels that remain constantly elevated, like an alarm clock that never stops ringing. This pattern is particularly common in women with PCOS, where high LH levels can interfere with normal ovulation and cause persistent symptoms like acne, hair growth, and weight gain around the midsection.
The Fertility Impact: Abnormal LH patterns can make conception feel like an impossible puzzle. Without a proper LH surge, ovulation becomes unpredictable or absent, making it difficult to time intercourse correctly. It's like trying to catch a train when you don't know the schedule—even if you're at the station, you might miss your opportunity.
In men, abnormal LH levels can indicate problems with testosterone production or testicular function. High LH in men often signals that the testes aren't responding properly to hormonal signals, like workers who can't hear their supervisor's instructions.
Perimenopause Signals: As you approach menopause, LH levels often become erratic before eventually rising permanently. These fluctuations can cause irregular periods, hot flushes, and mood changes years before menopause officially begins. It's your body's way of signalling that your reproductive system is starting to wind down, like a clock that's beginning to lose its precise timing.
When LH Levels Signal Trouble
Irregular LH Patterns: When LH levels don't follow their normal pattern, it's like having a faulty alarm clock that either doesn't ring or rings at the wrong time. You might experience irregular periods, with cycles that are much longer or shorter than normal, or you might skip periods entirely. This disruption often indicates that ovulation isn't occurring regularly or at all.
Some women have LH levels that remain constantly elevated, like an alarm clock that never stops ringing. This pattern is particularly common in women with PCOS, where high LH levels can interfere with normal ovulation and cause persistent symptoms like acne, hair growth, and weight gain around the midsection.
The Fertility Impact: Abnormal LH patterns can make conception feel like an impossible puzzle. Without a proper LH surge, ovulation becomes unpredictable or absent, making it difficult to time intercourse correctly. It's like trying to catch a train when you don't know the schedule—even if you're at the station, you might miss your opportunity.
In men, abnormal LH levels can indicate problems with testosterone production or testicular function. High LH in men often signals that the testes aren't responding properly to hormonal signals, like workers who can't hear their supervisor's instructions.
Perimenopause Signals: As you approach menopause, LH levels often become erratic before eventually rising permanently. These fluctuations can cause irregular periods, hot flushes, and mood changes years before menopause officially begins. It's your body's way of signalling that your reproductive system is starting to wind down, like a clock that's beginning to lose its precise timing.
When LH Levels Signal Trouble
Irregular LH Patterns: When LH levels don't follow their normal pattern, it's like having a faulty alarm clock that either doesn't ring or rings at the wrong time. You might experience irregular periods, with cycles that are much longer or shorter than normal, or you might skip periods entirely. This disruption often indicates that ovulation isn't occurring regularly or at all.
Some women have LH levels that remain constantly elevated, like an alarm clock that never stops ringing. This pattern is particularly common in women with PCOS, where high LH levels can interfere with normal ovulation and cause persistent symptoms like acne, hair growth, and weight gain around the midsection.
The Fertility Impact: Abnormal LH patterns can make conception feel like an impossible puzzle. Without a proper LH surge, ovulation becomes unpredictable or absent, making it difficult to time intercourse correctly. It's like trying to catch a train when you don't know the schedule—even if you're at the station, you might miss your opportunity.
In men, abnormal LH levels can indicate problems with testosterone production or testicular function. High LH in men often signals that the testes aren't responding properly to hormonal signals, like workers who can't hear their supervisor's instructions.
Perimenopause Signals: As you approach menopause, LH levels often become erratic before eventually rising permanently. These fluctuations can cause irregular periods, hot flushes, and mood changes years before menopause officially begins. It's your body's way of signalling that your reproductive system is starting to wind down, like a clock that's beginning to lose its precise timing.
What Disrupts Your LH Production
Stress: Chronic stress acts like a hormone hijacker, disrupting the delicate communication between your brain and ovaries that controls LH production. When you're stressed, your body prioritises survival over reproduction, suppressing LH release and throwing off your ovulation timing.
Extremes of weight: Being significantly underweight or overweight can interfere with LH production like static disrupting a radio signal. Your body needs adequate energy reserves to support reproduction, so extreme weight loss can shut down LH production entirely. Conversely, excess weight can alter hormone metabolism and disrupt normal LH patterns, creating a feedback loop that makes both weight management and fertility more challenging.
Medical Conditions: Conditions like PCOS, thyroid disorders, or pituitary problems can dramatically affect LH levels. PCOS, in particular, often causes persistently elevated LH levels that prevent normal ovulation. These conditions act like interference signals, disrupting the normal feedback loops that control LH production.
Pituitary tumours, though rare, can also affect LH production by physically interfering with the gland that produces this crucial hormone. It's like having a blocked transmission tower that can't send clear signals to the reproductive organs.
Lifestyle Factors: Excessive exercise, particularly endurance training, can suppress LH production gradually reducing the hormone's output. Your body interprets intense training as a survival stress, prioritising energy for immediate needs over reproductive function.
Certain medications, eating disorders, and sleep disruption can also interfere with the brain signals that control LH release. Even jet lag and shift work can throw off your LH patterns by disrupting your body's internal clock.
What Disrupts Your LH Production
Stress: Chronic stress acts like a hormone hijacker, disrupting the delicate communication between your brain and ovaries that controls LH production. When you're stressed, your body prioritises survival over reproduction, suppressing LH release and throwing off your ovulation timing.
Extremes of weight: Being significantly underweight or overweight can interfere with LH production like static disrupting a radio signal. Your body needs adequate energy reserves to support reproduction, so extreme weight loss can shut down LH production entirely. Conversely, excess weight can alter hormone metabolism and disrupt normal LH patterns, creating a feedback loop that makes both weight management and fertility more challenging.
Medical Conditions: Conditions like PCOS, thyroid disorders, or pituitary problems can dramatically affect LH levels. PCOS, in particular, often causes persistently elevated LH levels that prevent normal ovulation. These conditions act like interference signals, disrupting the normal feedback loops that control LH production.
Pituitary tumours, though rare, can also affect LH production by physically interfering with the gland that produces this crucial hormone. It's like having a blocked transmission tower that can't send clear signals to the reproductive organs.
Lifestyle Factors: Excessive exercise, particularly endurance training, can suppress LH production gradually reducing the hormone's output. Your body interprets intense training as a survival stress, prioritising energy for immediate needs over reproductive function.
Certain medications, eating disorders, and sleep disruption can also interfere with the brain signals that control LH release. Even jet lag and shift work can throw off your LH patterns by disrupting your body's internal clock.
What Disrupts Your LH Production
Stress: Chronic stress acts like a hormone hijacker, disrupting the delicate communication between your brain and ovaries that controls LH production. When you're stressed, your body prioritises survival over reproduction, suppressing LH release and throwing off your ovulation timing.
Extremes of weight: Being significantly underweight or overweight can interfere with LH production like static disrupting a radio signal. Your body needs adequate energy reserves to support reproduction, so extreme weight loss can shut down LH production entirely. Conversely, excess weight can alter hormone metabolism and disrupt normal LH patterns, creating a feedback loop that makes both weight management and fertility more challenging.
Medical Conditions: Conditions like PCOS, thyroid disorders, or pituitary problems can dramatically affect LH levels. PCOS, in particular, often causes persistently elevated LH levels that prevent normal ovulation. These conditions act like interference signals, disrupting the normal feedback loops that control LH production.
Pituitary tumours, though rare, can also affect LH production by physically interfering with the gland that produces this crucial hormone. It's like having a blocked transmission tower that can't send clear signals to the reproductive organs.
Lifestyle Factors: Excessive exercise, particularly endurance training, can suppress LH production gradually reducing the hormone's output. Your body interprets intense training as a survival stress, prioritising energy for immediate needs over reproductive function.
Certain medications, eating disorders, and sleep disruption can also interfere with the brain signals that control LH release. Even jet lag and shift work can throw off your LH patterns by disrupting your body's internal clock.
Understanding Your Results
LH levels vary dramatically throughout your cycle, making interpretation complex. Understanding these ranges helps you know whether your ovulation trigger is working properly:
Men:
Normal: 1.7-8.6 IU/L
Women:
Normal: 1-95.6 IU/L or higher
Women (Post menopausal):
Normal: 7.7-58.5 IU/L or higher
Timing Your Test: In women, the timing of your LH test is crucial for accurate interpretation. Testing during the wrong phase of your cycle can give misleading results, like checking your speedometer whilst parked and concluding your car can't go fast. Your doctor will carefully time the test based on your cycle patterns and symptoms.
For women trying to conceive, multiple LH tests or home ovulation kits might be recommended to track the surge pattern and identify the optimal fertile window.
The Bigger Picture: Your doctor won't interpret LH results in isolation. They'll consider your symptoms, other hormone levels, and medical history to create a complete picture of your reproductive health. It's like solving a puzzle—one piece alone doesn't tell the whole story, but when combined with other information, it reveals important insights about your fertility and overall health.
Understanding Your Results
LH levels vary dramatically throughout your cycle, making interpretation complex. Understanding these ranges helps you know whether your ovulation trigger is working properly:
Men:
Normal: 1.7-8.6 IU/L
Women:
Normal: 1-95.6 IU/L or higher
Women (Post menopausal):
Normal: 7.7-58.5 IU/L or higher
Timing Your Test: In women, the timing of your LH test is crucial for accurate interpretation. Testing during the wrong phase of your cycle can give misleading results, like checking your speedometer whilst parked and concluding your car can't go fast. Your doctor will carefully time the test based on your cycle patterns and symptoms.
For women trying to conceive, multiple LH tests or home ovulation kits might be recommended to track the surge pattern and identify the optimal fertile window.
The Bigger Picture: Your doctor won't interpret LH results in isolation. They'll consider your symptoms, other hormone levels, and medical history to create a complete picture of your reproductive health. It's like solving a puzzle—one piece alone doesn't tell the whole story, but when combined with other information, it reveals important insights about your fertility and overall health.
Understanding Your Results
LH levels vary dramatically throughout your cycle, making interpretation complex. Understanding these ranges helps you know whether your ovulation trigger is working properly:
Men:
Normal: 1.7-8.6 IU/L
Women:
Normal: 1-95.6 IU/L or higher
Women (Post menopausal):
Normal: 7.7-58.5 IU/L or higher
Timing Your Test: In women, the timing of your LH test is crucial for accurate interpretation. Testing during the wrong phase of your cycle can give misleading results, like checking your speedometer whilst parked and concluding your car can't go fast. Your doctor will carefully time the test based on your cycle patterns and symptoms.
For women trying to conceive, multiple LH tests or home ovulation kits might be recommended to track the surge pattern and identify the optimal fertile window.
The Bigger Picture: Your doctor won't interpret LH results in isolation. They'll consider your symptoms, other hormone levels, and medical history to create a complete picture of your reproductive health. It's like solving a puzzle—one piece alone doesn't tell the whole story, but when combined with other information, it reveals important insights about your fertility and overall health.
The Takeaway
LH levels provide crucial insights into your ovulation patterns, fertility potential, and overall reproductive health. Whether you're trying to conceive, experiencing irregular periods, or approaching menopause, understanding your LH patterns can help explain what's happening in your body and guide appropriate treatment decisions.
If you're struggling with irregular cycles, difficulty conceiving, or unexplained reproductive symptoms, your LH levels could be providing important clues about the underlying cause.
A simple blood test can determine whether your LH levels are supporting healthy ovulation or signalling that something needs attention. Don't ignore persistent menstrual irregularities or fertility problems, assuming they'll resolve on their own. One small test can give you the clarity you need to understand your body's reproductive rhythm and take appropriate action to optimise your fertility and wellbeing.
The Takeaway
LH levels provide crucial insights into your ovulation patterns, fertility potential, and overall reproductive health. Whether you're trying to conceive, experiencing irregular periods, or approaching menopause, understanding your LH patterns can help explain what's happening in your body and guide appropriate treatment decisions.
If you're struggling with irregular cycles, difficulty conceiving, or unexplained reproductive symptoms, your LH levels could be providing important clues about the underlying cause.
A simple blood test can determine whether your LH levels are supporting healthy ovulation or signalling that something needs attention. Don't ignore persistent menstrual irregularities or fertility problems, assuming they'll resolve on their own. One small test can give you the clarity you need to understand your body's reproductive rhythm and take appropriate action to optimise your fertility and wellbeing.
The Takeaway
LH levels provide crucial insights into your ovulation patterns, fertility potential, and overall reproductive health. Whether you're trying to conceive, experiencing irregular periods, or approaching menopause, understanding your LH patterns can help explain what's happening in your body and guide appropriate treatment decisions.
If you're struggling with irregular cycles, difficulty conceiving, or unexplained reproductive symptoms, your LH levels could be providing important clues about the underlying cause.
A simple blood test can determine whether your LH levels are supporting healthy ovulation or signalling that something needs attention. Don't ignore persistent menstrual irregularities or fertility problems, assuming they'll resolve on their own. One small test can give you the clarity you need to understand your body's reproductive rhythm and take appropriate action to optimise your fertility and wellbeing.
References
British Fertility Society. (2020). Luteinising hormone testing in reproductive medicine. Human Reproduction Guidelines.
National Institute for Health and Care Excellence. (2019). Fertility problems: assessment and treatment. NICE Clinical Guideline.
Royal College of Obstetricians and Gynaecologists. (2021). Ovulation disorders and LH monitoring. BJOG Practice Guidelines.
References
British Fertility Society. (2020). Luteinising hormone testing in reproductive medicine. Human Reproduction Guidelines.
National Institute for Health and Care Excellence. (2019). Fertility problems: assessment and treatment. NICE Clinical Guideline.
Royal College of Obstetricians and Gynaecologists. (2021). Ovulation disorders and LH monitoring. BJOG Practice Guidelines.
References
British Fertility Society. (2020). Luteinising hormone testing in reproductive medicine. Human Reproduction Guidelines.
National Institute for Health and Care Excellence. (2019). Fertility problems: assessment and treatment. NICE Clinical Guideline.
Royal College of Obstetricians and Gynaecologists. (2021). Ovulation disorders and LH monitoring. BJOG Practice Guidelines.
Research articles
Research articles
Control your preventive health with Emerald
Subscribe to our newsletter
© 2025 Emerald Labs Ltd
Subscribe to our newsletter
© 2025 Emerald Labs Ltd
Subscribe to our newsletter
© 2025 Emerald Labs Ltd
Subscribe to our newsletter
© 2025 Emerald Labs Ltd
Subscribe to our newsletter
© 2025 Emerald Labs Ltd