Pregnenolone for Neurosteroid & Hormonal Support — Testosterone & Androgens
Endogenous steroid hormone precursor ('mother of all hormones') available OTC as supplement with limited clinical evidence for cognitive and hormonal support.
Overview
Pregnenolone is an endogenous steroid hormone synthesized from cholesterol via the enzyme CYP11A1 (cholesterol side-chain cleavage enzyme) in the adrenal glands, gonads, brain, and other steroidogenic tissues. It serves as the precursor to virtually all other steroid hormones, earning it the designation 'mother of all hormones' — downstream metabolites include DHEA, progesterone, cortisol, testosterone, estradiol, and aldosterone. In the brain, pregnenolone and its sulfated metabolite pregnenolone sulfate (PREG-S) function as neurosteroids, modulating GABA-A, NMDA, and sigma-1 receptors. PREG-S is a positive allosteric modulator of NMDA receptors and a negative modulator of GABA-A receptors, producing cognitive-enhancing and memory-promoting effects in preclinical models. Circulating pregnenolone levels decline significantly with age, decreasing by approximately 60% between ages 35 and 75. While pregnenolone supplementation is widely available OTC and promoted for memory, mood, energy, and hormonal balance, robust clinical trial data are sparse. Small pilot studies in schizophrenia showed modest cognitive improvement, and a pilot trial in chronic low back pain showed some benefit. However, placebo-controlled RCTs specifically for healthy aging or hormonal optimization are lacking. The conversion of exogenous pregnenolone into downstream hormones is unpredictable and varies between individuals, complicating dose-response relationships.
Indications
- Weak evidence: Cognitive enhancement and memory support (neurosteroid activity)
- Weak evidence: Hormonal precursor supplementation during aging
- Preliminary: Schizophrenia adjunctive therapy (pilot studies)
- Preliminary: Chronic pain management (pilot data)
- Traditional use: Fatigue, mood, and overall hormonal balance
- Theoretical: Age-related steroid hormone decline compensation
Mechanism of Action
CYP11A1 cleaves the cholesterol side chain to produce pregnenolone, the first committed step in steroidogenesis
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Pregnenolone | 10-25 mg | Once daily (morning) | Conservative starting dose for general support |
| Pregnenolone | 50 mg | Once daily (morning) | Moderate dose; monitor for hormonal side effects |
| Pregnenolone | 100-200 mg | Once daily | Doses used in schizophrenia pilot studies; not routine |
Evidence Grade
GRADE D
Safety & Contraindications
- As a steroid precursor, may convert to unpredictable downstream hormones (testosterone, estrogen, cortisol)
- May worsen hormone-sensitive conditions (breast cancer, prostate cancer, endometriosis)
- Insomnia, irritability, anger, and acne reported at higher doses
- Heart palpitations and headache possible
- Avoid in pregnancy — steroid precursor with unknown fetal effects
- Potential interference with hormonal laboratory values — inform treating physician