What Is Pregnenolone?
Pregnenolone is a naturally occurring steroid synthesized from cholesterol and is often described as the upstream or "master" precursor of steroidogenesis. In steroid-producing cells, cholesterol is transported into the mitochondrial inner membrane by the steroidogenic acute regulatory protein, commonly abbreviated StAR. There, the cholesterol side-chain-cleavage enzyme CYP11A1, also called P450scc, converts cholesterol into pregnenolone. This first reaction initiates several interconnected pathways that produce progesterone, dehydroepiandrosterone (DHEA), androstenedione, testosterone, estrogens, cortisol, aldosterone, and other steroid hormones. The direction and amount of conversion depend on tissue-specific enzymes, cellular signals, sex, age, metabolic state, and endocrine feedback. Pregnenolone is therefore not simply a reservoir that is uniformly converted into every downstream hormone; it is a branching intermediate whose fate differs among the adrenal cortex, gonads, placenta, peripheral tissues, and nervous system.
Pregnenolone also has a second identity as a neurosteroid. Steroids made within the brain, or synthesized there from circulating precursors, can act rapidly on neuronal receptors independently of classical genomic hormone signaling. Pregnenolone and its sulfated metabolite, pregnenolone sulfate, have been investigated for effects on memory, excitability, synaptic plasticity, stress responses, and neuroprotection. Brain steroidogenesis was recognized as biologically important through work showing that some steroids are present in the nervous system even when peripheral endocrine sources are limited, and that neural tissue contains steroidogenic enzymes. Pregnenolone sulfate has a receptor profile that differs from unconjugated pregnenolone and is more strongly associated in experimental systems with modulation of NMDA, GABA-A, nicotinic acetylcholine, sigma, and other signaling systems. Circulating DHEA and some neurosteroid measures generally decline with age, prompting the hypothesis that reduced steroidogenic capacity may contribute to an age-related state sometimes called "steroidogenic insufficiency." This concept remains a research model rather than a universally accepted clinical diagnosis, and low pregnenolone alone does not establish that supplementation is appropriate.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Pregnenolone treatment in schizophrenia: a double-blind, placebo-controlled trial
Ritsner, M. S., Bawakny, H., Kreinin, A., et al., 2010, Journal of Clinical Psychiatry - Pregnenolone treatment of schizophrenia: a randomized, double-blind, placebo-controlled trial
Mayo, L. M., et al., 2014, Neuropsychopharmacology - A randomized controlled trial of pregnenolone and symptom reduction in veterans with chronic posttraumatic stress disorder
Rasmusson, A. M., Marx, C. E., Jain, S., et al., 2016, JAMA Psychiatry - Pregnenolone as a novel therapeutic candidate in schizophrenia: emerging preclinical and clinical evidence
Marx, C. E., Bradford, D. W., Hamer, R. M., et al., 2011, Neuroscience - Neurosteroids: a novel function in the brain
Vallée, M., Mayo, W., Le Moal, M., 2001, Brain Research Reviews