Pregnenolone is the master precursor hormone — often called the "mother steroid hormone" because it serves as the precursor to most steroid hormones in the body, including progesterone, DHEA, cortisol, estrogens, and testosterone. It is produced primarily from cholesterol in the adrenal glands, gonads, and brain.
The blood test measures serum pregnenolone, most commonly using liquid chromatography-mass spectrometry (LC/MS) — which is why many lab reports list this result as Pregnenolone, LC/MS or Pregnenolone, MS.
Pregnenolone — quick answer
- Normal range (adults ≥18): 33–248 ng/dL (LabCorp reference range)
- High result: Most commonly caused by congenital adrenal hyperplasia (CAH), adrenal disorders, or enzyme deficiencies in the steroid pathway
- Low result: Associated with aging-related hormone decline, chronic stress, adrenal insufficiency, and nutrient deficiencies
- "LC/MS" on your report: Means the test was run by liquid chromatography-mass spectrometry — a highly sensitive measurement method, not a separate test
- Also called: Pregnenolone, MS; Pregnenolone Sulfate; Pregnenolone, LC/MS/MS
What does "Pregnenolone, LC/MS" mean?
LC/MS stands for liquid chromatography-mass spectrometry — the analytical method used to measure pregnenolone in the blood. It is more sensitive and specific than older immunoassay methods and is now the standard method at most major reference labs including LabCorp and Quest.
When your lab report shows Pregnenolone, LC/MS or Pregnenolone, MS, it simply means the pregnenolone level was measured by this method. There is no clinical difference in interpretation — it is the same biomarker measured with high accuracy.
What does pregnenolone do?
Pregnenolone sits at the top of the steroid hormone synthesis pathway:
Cholesterol → Pregnenolone →
- → Progesterone → Cortisol, Aldosterone
- → DHEA → Testosterone, Estrogens
- → Neurosteroids (allopregnanolone, DHEA-S) — active in the brain
Because pregnenolone is the starting point for this entire pathway, abnormalities in pregnenolone production affect downstream hormones across the entire steroid cascade. This is why pregnenolone testing is used in evaluating hormonal imbalances, adrenal function, and suspected CAH.
Pregnenolone normal range and levels by age
Pregnenolone levels decline significantly with age — a well-documented phenomenon. Levels peak in young adulthood and fall by more than 60% by age 75.
Adult reference range (≥18 years): 33–248 ng/dL
Pediatric reference ranges:
| Age | Males | Females |
|---|---|---|
| 0–6 years | Not established | Not established |
| 7–9 years | <206 ng/dL | <151 ng/dL |
| 10–12 years | <152 ng/dL | 19–220 ng/dL |
| 13–15 years | 18–197 ng/dL | 22–210 ng/dL |
| 16–17 years | 17–228 ng/dL | 22–229 ng/dL |
| ≥18 years | 33–248 ng/dL | 33–248 ng/dL |
Tanner stage reference ranges (males):
| Stage | Range |
|---|---|
| Stage I | <157 ng/dL |
| Stage II | <144 ng/dL |
| Stage III | <215 ng/dL |
| Stage IV–V | 19–201 ng/dL |
Tanner stage reference ranges (females):
| Stage | Range |
|---|---|
| Stage I | <172 ng/dL |
| Stage II | 22–229 ng/dL |
| Stage III | 34–215 ng/dL |
| Stage IV–V | 26–235 ng/dL |
Source: LabCorp reference ranges. Always use the range printed on your report.
Age-related decline: Pregnenolone production falls progressively after peak levels in early adulthood. By the sixth and seventh decade, circulating levels may be less than half of young adult values. This decline parallels the broader reduction in adrenal steroid output (adrenopause) and is a key reason functional medicine practitioners monitor pregnenolone alongside DHEA-S, cortisol, and sex hormones.
What causes high pregnenolone?
Elevated pregnenolone most commonly reflects a block in the steroid synthesis pathway — the body is producing pregnenolone but cannot efficiently convert it to downstream hormones.
Causes of high pregnenolone:
- Congenital adrenal hyperplasia (CAH) — the most clinically significant cause. Enzyme deficiencies (most commonly 21-hydroxylase, 17α-hydroxylase, or 3β-HSD deficiency) block conversion of pregnenolone into cortisol and other hormones, causing pregnenolone to accumulate
- Adrenal tumors — adrenocortical tumors can overproduce steroid precursors
- Polycystic ovary syndrome (PCOS) — enzyme dysregulation in the steroid pathway can elevate pregnenolone in some women
- Stress — HPA-axis activation may alter pregnenolone production and downstream steroid hormone balance; the direction of effect depends on pathway dynamics and the duration of the stress response
- Pregnancy — physiologically elevated due to placental steroid production
- Pregnenolone supplementation — exogenous pregnenolone is a common cause of elevated levels; always report supplement use to your doctor
Symptoms of high pregnenolone: Symptoms associated with elevated pregnenolone are usually driven by downstream hormonal imbalance rather than pregnenolone itself. High pregnenolone may divert through alternative enzyme pathways, affecting androgen or estrogen levels. In CAH, accumulated pregnenolone may be diverted toward androgens, causing virilization. In isolation, high pregnenolone with supplement use may cause irritability, insomnia, acne, or increased facial/body hair in women.
What causes low pregnenolone?
Low pregnenolone most commonly reflects reduced adrenal steroidogenic capacity, often related to aging, chronic stress, or nutrient deficiencies.
Causes of low pregnenolone:
- Aging — the most common cause; adrenal pregnenolone production declines progressively with age, mirroring the broader decline in DHEA-S and adrenal steroid output
- Adrenal insufficiency or dysfunction — conditions reducing overall adrenal steroid output will lower pregnenolone
- Chronic illness — prolonged illness or physiological stress may suppress steroidogenesis broadly
- Chronic stress — sustained HPA activation may influence the steroid pathway distribution, though the clinical evidence for pregnenolone-specific effects is limited
- Medications and other factors — certain medications, sleep disruption, and nutritional status may indirectly influence levels
Nutritional status, sleep quality, thyroid function, and medication use may influence steroid hormone production indirectly, but their specific effects on pregnenolone levels are not firmly established clinically.
Symptoms of low pregnenolone: Low pregnenolone may contribute to fatigue, brain fog, poor memory, low mood, decreased libido, reduced stress tolerance, and hormonal imbalances — though these symptoms are non-specific and overlap with many conditions. Because pregnenolone is a precursor to multiple hormones, low levels may manifest through downstream hormone deficiencies rather than as a direct symptom pattern.
What is "pregnenolone steal"?
"Pregnenolone steal" (also called "cortisol steal") is a functional medicine concept describing how chronic stress may prioritize cortisol production at the expense of other steroid hormones. Because cortisol and sex hormones share pregnenolone as a common precursor, sustained high demand for cortisol output may reduce available pregnenolone for DHEA, progesterone, and sex hormone synthesis.
The evidence base for pregnenolone steal as a clinical entity is limited — it describes a plausible pathway effect rather than a rigorously proven mechanism. However, the pattern of low DHEA-S, low sex hormones, and elevated or normal cortisol in the context of chronic stress is clinically recognized.
Should pregnenolone be tested alone?
Pregnenolone is rarely interpreted in isolation. Because it sits at the top of the steroid synthesis cascade, a single pregnenolone value only becomes clinically meaningful when reviewed alongside the hormones it produces. Clinicians typically evaluate it as part of a broader panel including DHEA-S, cortisol, 17-hydroxyprogesterone, testosterone, estradiol, progesterone, LH, and FSH.
An elevated pregnenolone with normal downstream hormones suggests a different cause than elevated pregnenolone with suppressed androgens or cortisol. Similarly, low pregnenolone with low DHEA-S and low cortisol suggests a different pathway problem than low pregnenolone with normal downstream hormones. The ratio and pattern across the steroid cascade matters more than any single value. HealthMatters tracks all of these related biomarkers so you can see the full steroid pathway picture in one place.
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Frequently Asked Questions
What is pregnenolone?
What does "Pregnenolone, LC/MS" mean on a lab report?
What is the normal pregnenolone level?
What causes high pregnenolone?
What are the symptoms of high pregnenolone?
What causes low pregnenolone?
What are the symptoms of low pregnenolone?
How do pregnenolone levels change with age?
What is "pregnenolone steal"?
What other tests are ordered alongside pregnenolone?
Does pregnenolone decline with age?
Should I take pregnenolone supplements?
All our content is backed by peer-reviewed studies, academic research, and trusted medical sources. We’re committed to accuracy and transparency — see our editorial policy for details.
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Circulating levels of allopregnanolone in humans: gender, age, and endocrine influences
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DHEA in elderly women and DHEA or testosterone in elderly men
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Pregnenolone, Mass Spectrometry (Endocrine Sciences)