Pregnenolone
Also known as: PREG
What Does Pregnenolone Measure?
Pregnenolone is a naturally occurring steroid hormone produced primarily in the adrenal glands, brain, liver, skin, and gonads. It is synthesized directly from cholesterol and serves as the foundational 'mother hormone' of the steroidogenesis pathway, meaning virtually all other steroid hormones — including progesterone, DHEA, cortisol, estrogen, and testosterone — are derived from it. A blood or serum test measures the circulating level of pregnenolone in the bloodstream, reflecting both production capacity and the health of the adrenal and neurological systems.
Why Does Pregnenolone Matter?
Pregnenolone plays a crucial role in brain function, mood regulation, memory, and stress response. As a neurosteroid, it modulates GABA and NMDA receptors in the brain, influencing cognition, anxiety, and neuroprotection. Because it is the precursor to all other steroid hormones, low pregnenolone levels can cascade into deficiencies of cortisol, DHEA, progesterone, and sex hormones, leading to widespread symptoms including fatigue, poor stress tolerance, depression, cognitive decline, and hormonal imbalances. Monitoring pregnenolone is particularly relevant in adrenal insufficiency, hormonal aging, chronic stress, and neurodegenerative conditions.
Normal Ranges
Males
10–200 ng/dL (varies by lab; some reference 22–237 ng/dL for adult males)
Females
10–230 ng/dL (varies by lab and menstrual cycle phase)
Children
Varies by age; neonates may have elevated levels that decline through childhood
Causes of High Levels
- Congenital adrenal hyperplasia (CAH) — enzyme deficiencies block downstream conversion, causing pregnenolone to accumulate
- Pregnenolone supplementation or exogenous hormone use
- Certain adrenal tumors or hyperplasia increasing steroidogenesis
- Stress-related hormonal dysregulation causing upstream steroid buildup
- Liver dysfunction impairing hormone metabolism and clearance
- High-dose cholesterol precursor loading without adequate enzyme activity
Causes of Low Levels
- Adrenal insufficiency or adrenal fatigue reducing overall steroidogenesis
- Aging — pregnenolone production naturally declines with age, particularly after age 35
- Chronic physical or psychological stress depleting adrenal reserve
How to Improve Your Pregnenolone
Diet
- Consume adequate healthy fats and dietary cholesterol (eggs, fatty fish, avocado) as cholesterol is the direct precursor to pregnenolone
- Eat zinc-rich foods such as oysters, beef, pumpkin seeds, and legumes to support adrenal enzyme function
- Include B-vitamin rich foods (leafy greens, whole grains, liver) to support steroidogenesis cofactors
- Reduce refined sugars and processed foods that contribute to chronic inflammation and adrenal stress
- Add adaptogenic foods like ashwagandha root and medicinal mushrooms to support adrenal health
Supplements
- Pregnenolone supplements: typically 10–50 mg/day, but only under physician supervision due to hormonal cascade effects
- DHEA 25–50 mg/day (physician-supervised) to support the steroid hormone pathway
- Vitamin C 500–1000 mg/day to support adrenal cortex function and cortisol production
- Magnesium glycinate 200–400 mg/day to reduce adrenal stress response and support enzyme activity
- Zinc 15–30 mg/day to support steroidogenic enzyme cofactor activity
Related Biomarkers
Frequently Asked Questions
What is pregnenolone and why is it called the 'mother hormone'?
Pregnenolone is called the 'mother hormone' because it is the very first steroid hormone synthesized from cholesterol in the body, and nearly all other steroid hormones — including cortisol, DHEA, progesterone, testosterone, and estrogen — are made from it. Without adequate pregnenolone, the entire steroid hormone cascade can be disrupted, leading to widespread hormonal deficiencies.
What are the symptoms of low pregnenolone?
Low pregnenolone can cause a broad range of symptoms because it affects the production of multiple downstream hormones. Common symptoms include persistent fatigue, brain fog, poor memory and concentration, depression or low mood, decreased libido, poor stress tolerance, anxiety, joint pain, and accelerated aging. Because these symptoms overlap with many conditions, a blood test is needed to confirm low levels.
Is it safe to take pregnenolone supplements?
Pregnenolone supplements are available over-the-counter in many countries, but they should be used cautiously and ideally under physician supervision. Because pregnenolone converts into multiple hormones including estrogen, progesterone, and testosterone, unsupervised use can cause unintended hormonal side effects such as acne, mood swings, hair loss, or hormonal imbalances. Dosages typically range from 5–50 mg/day, and periodic lab testing is recommended to monitor levels.
Does pregnenolone decline with age?
Yes, pregnenolone levels naturally and significantly decline with aging. Production peaks in young adulthood and can fall by as much as 60% by the time a person reaches their 75s. This age-related decline is believed to contribute to reduced cognitive function, memory problems, fatigue, and the decreased output of other hormones like DHEA, testosterone, and progesterone seen in older adults.