Pregnenolone
The "mother hormone" — your body's starting material for cortisol, DHEA, testosterone, estrogen, and progesterone. It also has direct effects on memory and mood.
Pregnenolone sits at the very top of your hormone cascade. Your body makes it from cholesterol, then converts it into every steroid hormone you need. Beyond being a precursor, it's also a neurosteroid — it directly enhances memory, protects brain cells, and supports mood. Levels decline with age, just like DHEA.
Good for you if: You're over 40 experiencing brain fog, low energy, or hormonal decline — and you want to support the whole cascade rather than supplementing individual hormones.
Dive deeper into the researchCommon side effects
- Irritability or overstimulation at higher doses
- Headache, especially in the first week
- Acne if converting heavily to androgens
What does pregnenolone do?
Think of pregnenolone as the trunk of your hormone tree. Cholesterol gets converted into pregnenolone, and from there it branches into two main pathways: one leads to cortisol (your stress hormone), the other to DHEA and then to testosterone and estrogen.
But pregnenolone isn't just a passive building block. In your brain, it acts as a neurosteroid — directly enhancing memory formation, protecting neurons from stress damage, and modulating mood through GABA and NMDA receptors. This is why many people notice cognitive benefits before any hormonal changes.
What can you expect?
- Sharper memory — clearer recall, less "tip of the tongue" moments
- Better mood — calmer, more emotionally resilient
- More energy — not stimulant-like, but a natural "switched on" feeling
- Hormonal support — gentle, broad-spectrum hormone balancing
- Better sleep quality — through progesterone pathway support
How to take it
5–15 mg in the morning with food. Start at the lower end. Pregnenolone is potent — a little goes a long way.
Some longevity practitioners use up to 30 mg/day, but only with regular blood monitoring. More is definitely not better here.
Sublingual vs oral: Sublingual tablets absorb faster and bypass first-pass liver metabolism. Oral capsules work fine but may convert more heavily to cortisol. Many practitioners prefer sublingual for cognitive benefits.
Cycling: Consider 5 days on, 2 days off — or 3 weeks on, 1 week off. This helps prevent receptor downregulation.
Pregnenolone vs DHEA
Both decline with age, and both are hormone precursors. But they sit at different levels of the cascade:
- Pregnenolone is upstream — it can become cortisol, progesterone, DHEA, testosterone, or estrogen. More versatile but less predictable in where it goes.
- DHEA is downstream — it mainly becomes testosterone and estrogen. More targeted but narrower in scope.
- Cognitive benefits are unique to pregnenolone. DHEA doesn't have the same direct neurosteroid activity.
Some people take both, using pregnenolone for brain support and DHEA specifically for sex hormone levels. If you're only choosing one, pregnenolone is the broader option.
Track your full hormone cascade alongside pregnenolone
eterni logs pregnenolone, DHEA-S, cortisol, and downstream hormones together — so you can see where your body is routing the precursor.
Get early accessFrequently Asked Questions
What is pregnenolone used for?
Pregnenolone is a hormone precursor your body uses to make cortisol, DHEA, progesterone, testosterone, and estrogen. People supplement it for cognitive enhancement (memory and clarity), mood support, hormonal balance, and anti-ageing. It's sometimes called the "mother hormone" because all steroid hormones downstream depend on it.
Is pregnenolone safe to take?
At low doses (5–30 mg/day), pregnenolone is generally well-tolerated. Because it sits at the top of the hormone cascade, it can influence multiple hormones downstream. Side effects at higher doses can include irritability, acne, headache, and hormonal shifts. Blood work is recommended before starting and during use.
Pregnenolone vs DHEA — what's the difference?
Pregnenolone is upstream of DHEA in the hormone cascade. Your body converts cholesterol → pregnenolone → DHEA → testosterone/estrogen. Pregnenolone is more versatile because it can become any downstream hormone, while DHEA mainly converts to sex hormones. Pregnenolone also has direct neurological benefits that DHEA doesn't share.
Does pregnenolone help with brain fog?
Many users report improved mental clarity and memory. Pregnenolone is a neurosteroid — it modulates GABA and NMDA receptors in the brain. Small clinical studies have shown memory improvements in older adults. However, large-scale trials are still lacking, so evidence is promising but not definitive.
How it works in your body
Pregnenolone is synthesised from cholesterol inside mitochondria via the enzyme CYP11A1 (cholesterol side-chain cleavage). From there, it enters two main biosynthetic pathways: the delta-5 pathway (→ DHEA → androgens/estrogens) and the delta-4 pathway (→ progesterone → cortisol/aldosterone).
As a neurosteroid, pregnenolone sulfate enhances NMDA receptor function (important for learning and memory) while also modulating GABA-A receptors. It promotes neurogenesis in the hippocampus and has neuroprotective effects against oxidative stress and inflammation.
What the studies show
- Memory: Pregnenolone sulfate improved spatial and verbal memory in animal models and small human studies
- Mood: Preliminary trials in depression and anxiety show promise, particularly in populations with low baseline levels
- Neuroprotection: Protects against amyloid-beta toxicity and supports myelin maintenance
- Age-related decline: Serum levels decrease approximately 60% between ages 35 and 75
Side effects & safety
Pregnenolone is generally safe at low doses, but because it feeds the entire hormone cascade, effects can be unpredictable:
- Irritability and anxiety — If your body routes pregnenolone heavily toward cortisol or androgens, you may feel wired or agitated. Lower the dose.
- Headache — Common in the first few days, especially at doses above 15 mg. Usually resolves.
- Acne — From androgen conversion, similar to DHEA side effects.
- Insomnia — Some people find it stimulating. If this happens, take it in the morning only.
- Hormonal shifts — Because pregnenolone can become any hormone, large doses can cause unexpected changes. Always monitor with blood work.
Who should skip it: People with hormone-sensitive cancers, anyone under 35 with normal hormone levels, pregnant or breastfeeding women. If you're on any hormone therapy, consult your doctor.
Which labs to check
- Pregnenolone (serum) — baseline before starting
- DHEA-S — see where the cascade is flowing
- Cortisol (morning) — make sure it's not rising too much
- Progesterone — especially for women, to track the delta-4 pathway
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