Pregnenolone
SupplementMedical evidence is limited to small proof-of-concept RCTs in specialized psychiatric indications [s6, s7, s8], while the community describes broad everyday use for cognition and energy [c1, c3]. The divergence reflects the gap between clinical evidence and subjective user experience.
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TL;DR
Pregnenolone has a solid mechanistic foundation as a neurosteroid and hormone precursor, but clinical evidence is limited to a handful of small RCTs in psychiatric populations — extrapolation to healthy users is speculative at best. The core risk is unpredictable downstream conversion to DHEA, progesterone, and testosterone, making hormonal side effects hard to anticipate. Community reports on energy, mood, and focus are mostly positive, but dose-dependent anxiety and sleep disruption are frequently cited downsides. Anyone using pregnenolone should monitor hormone levels via lab work before and during use — it is contraindicated in hormone-sensitive conditions.
Description
Pregnenolone is an endogenous neurosteroid and precursor to all steroid hormones; it modulates GABA-A, NMDA, and sigma-1 receptors and is used for cognition, mood, and menopausal symptoms...
Pregnenolone (P5) is the first steroid synthesized from cholesterol by the enzyme CYP11A1 in mitochondria [s3]. It is considered the "mother of all steroids," as it serves as the precursor for the biosynthesis of DHEA, progesterone, cortisol, testosterone, estrogens, and aldosterone [s3, s4]. In the brain, pregnenolone is detected at higher concentrations than in blood; it can cross the blood-brain barrier and is resulfated there to pregnenolone sulfate (PregS) [s2]. As a neurosteroid, pregnenolone acts directly on ionotropic receptors in the central nervous system: it inhibits GABA-A receptors (negative allosteric modulator), activates NMDA receptors (positive modulator), and acts as a weak sigma-1 receptor agonist [s1, s5]. Additionally, pregnenolone is a signal-specific inhibitor of the CB1 cannabinoid receptor [s1]. Clinical studies have been conducted primarily in schizophrenia [s6, s7], bipolar depression [s8], and substance use disorders with comorbidities [s9]. Evidence for healthy individuals is more limited. Pregnenolone levels decline significantly with age, contributing to the rationale for supplementation in older adults [s10]. Doses in studies typically ranged from 50 mg to 500 mg daily [s6, s7, s8].
Legal Status (DE)
In Germany, pregnenolone is marketable as a food supplement without authorization requirements at low doses (up to approx. 50 mg) and is available without prescription in pharmacies and online shops [s13]. Higher-dose magistral preparations (e.g., 1% cream) are compounded in pharmacies by prescription [s13]. No EU-wide harmonization exists; in some EU countries (e.g., Sweden), import may be restricted [s14]. No EMA marketing authorization as a medicinal product exists [s14].
Mechanism of Action
1. Steroidogenesis: Pregnenolone is formed from cholesterol by CYP11A1 in the mitochondria of the adrenal glands, gonads, and brain [s3]. It branches into two main pathways: the Δ5 pathway (→ DHEA → androstenediol → testosterone) and the Δ4 pathway (→ progesterone → cortisol/aldosterone) [s3, s4]. Supplementation can influence these downstream hormones, explaining hormonal side effects and interactions [s11]. 2. GABA-A receptor modulation: Pregnenolone and its sulfate ester PregS act as negative allosteric modulators at the GABA-A receptor, reducing chloride ion conductance and leading to increased neuronal excitability [s5]. This explains potential proconvulsant effects and contrasts with the sedating action of allopregnanolone [s5]. 3. NMDA receptor potentiation: PregS acts as a positive modulator at the NMDA receptor, enhancing glutamatergic transmission and potentially facilitating cognitive processes such as long-term potentiation and memory consolidation [s1, s2]. 4. Sigma-1 receptor agonism: Pregnenolone binds weakly to sigma-1 receptors; PregS as a more potent agonist modulates calcium channels and neurotrophic signaling pathways associated with antidepressant effects [s1]. 5. CB1 inhibition: Pregnenolone signal-specifically reduces the effect of THC at the CB1 receptor and has therefore been investigated as a potential intervention in cannabis misuse [s1].
Dosing
Kognition und Stimmung (allgemein)
- Dose
- 10–30 mg
- Frequency
- 1× täglich morgens
- Route
- oral
- Duration
- 4–12 Wochen, dann Pause evaluieren
- Timing
- Morning fasted or with breakfast
- With food
- optional
Schizophrenie-Augmentation (klinisch, unter ärztlicher Aufsicht)
- Dose
- 30–500 mg
- Frequency
- 1× täglich
- Route
- oral
- Duration
- 8 Wochen
- Timing
- Morning
- With food
- empfohlen
Bipolare Depression (klinisch, unter ärztlicher Aufsicht)
- Dose
- 500 mg
- Frequency
- 1× täglich
- Route
- oral
- Duration
- 12 Wochen
- Timing
- Morning
- With food
- empfohlen
Wechseljahresbeschwerden (Frau, ärztlich begleitet)
- Dose
- 30–50 mg
- Frequency
- 1× täglich
- Route
- oral
- Duration
- 6–12 Wochen, dann Reevaluation
- Timing
- Morning
- With food
- empfohlen
Doses above 50 mg daily increase the risk of hormonal side effects through conversion to active steroids and are not recommended without medical supervision [s11, s12]. Clinical studies have used up to 500 mg [s8], but exclusively under medical monitoring.
Due to the conversion potential to DHEA, progesterone, and testosterone, laboratory monitoring of hormone levels before and after use is recommended [s11]. Evening intake may cause sleep disturbances in some users [s12].
Side Effects
| Side Effect | Frequency | Severity |
|---|---|---|
| Unruhe, innere Nervosität NMDA potentiation and GABA-A inhibition by PregS can lead to increased neuronal excitability [s1, s5]. | gelegentlich | leicht |
| Schlafstörungen (Insomnie) Reported particularly with evening administration or higher doses via excitatory receptor mechanism [s12]. | gelegentlich | leicht |
| Stimmungsschwankungen, Reizbarkeit Hormonal conversion products (e.g., elevated testosterone or estrogen) can cause mood changes [s11]. | gelegentlich | leicht |
| Akne, vermehrte Körperbehaarung (Hirsutismus) Possible upon conversion to androgens (DHEA, testosterone), especially at higher doses [s11]. | selten | leicht |
| Kopfschmerzen Occasionally documented as an adverse event in clinical trials [s6]. | selten | leicht |
| Herzrasen (Palpitationen) Theoretically possible via adrenal conversion pathways (cortisol precursor); described in case reports [s11]. | selten | moderat |
| Erhöhte Hormonwerte (Testosteron, Östrogen, Cortisol) As pregnenolone is a precursor to all steroid hormones, supplementation may elevate downstream hormones, which can be clinically relevant [s3, s11]. | gelegentlich | moderat |
Contraindications
Pregnenolone is converted to estrogens, which may promote the growth of estrogen-dependent tumors [s11].
Elevated estrogen levels via conversion may exacerbate these estrogen-dependent conditions [s11].
Insufficient safety data; hormonal interference during a sensitive phase cannot be excluded [s11].
GABA-A inhibition by PregS may lower the seizure threshold and provoke seizures [s5].
Conversion to testosterone/DHT may stimulate androgen-dependent prostatic conditions [s11].
Additive hormone levels from concomitant use may result in exceeding therapeutic ranges [s11].
Interactions
Synergistic
Both are steroid precursors; combined use may additively increase androgen and estrogen levels [s3].
In an RCT with schizophrenia patients, the combination of pregnenolone + L-theanine showed improved negative symptoms and anxiety compared to pregnenolone alone [s7].
Ashwagandha significantly lowers cortisol levels (up to ~28% in studies), which may reduce the so-called "pregnenolone steal" by stress hormones. This leaves more pregnenolone available for the production of DHEA and sex hormones.
DIM promotes the metabolism of estrogens to less potent metabolites via CYP1A1/CYP3A4. In combination with pregnenolone, which serves as an estrogen precursor, DIM may attenuate excessive estrogen accumulation.
Calcium-D-glucarate inhibits beta-glucuronidase and promotes renal excretion of conjugated estrogens. When taken concomitantly with pregnenolone, this may reduce excessive estrogen accumulation resulting from pregnenolone conversion.
Caution
Additive hormonal exposure; risk of undesirable hyperstimulation of endocrine axes [s11].
Pregnenolone may attenuate anticonvulsant effects through GABA-A inhibition; interaction theoretically significant [s5].
Steroid hormones are metabolized via CYP enzymes; inducers (e.g., rifampicin) or inhibitors (e.g., ketoconazole) may alter pregnenolone levels and conversion [s3].
Antagonistic action at the GABA-A receptor by pregnenolone sulfate (PregS) may attenuate the effects of benzodiazepines [s5].
Pregnenolone can indirectly affect thyroid function (T4→T3 conversion) via increased cortisol production. Concurrent iodine supplementation carries the risk of undesirable interactions on the thyroid axis.
Studies
Tier A — High Evidence
Outcome: Improvement of schizophrenic symptoms (PANSS) in women under pregnenolone augmentation to risperidone
Effect Size: Significant improvement vs. placebo (see full publication J Psychiatr Res 2017;94:70–77 for details)
Outcome: Self-reported pain intensity (chronic back pain) in war veterans
Effect Size: Details in full publication (JAMA Netw Open 2020;3(3):e200287); Marx group reports positive preliminary findings as basis for ongoing TBI/PTSD phase 2 trial
Outcome: Reduction of negative symptoms (PANSS negative subscale) and anxiety symptoms (HAMA) with pregnenolone + L-theanine
Effect Size: Significant improvement in negative and anxiety symptoms vs. placebo; pregnenolone + L-theanine well tolerated. Exact effect size (Cohen's d) in full text, epub 2015.
Community Evidence
Top reported benefits
- Improved focus and mental clarity, especially in the morning
- Mood elevation and reduced brain fog
- Increased energy without stimulant-like effects
- Improvement in memory and concentration in menopausal women
- Reduction of racing thoughts and inner restlessness (paradoxical calming effect at low doses)
Top reported issues
- Sleep disturbances with evening administration or higher doses
- Restlessness and inner agitation, especially at the beginning
- Mood swings and irritability
- Uncertainty about correct dosing and hormonal side effects
- No noticeable effect in a subset of users
Several Reddit users report difficult-to-predict hormonal effects (e.g., unexpected increases in testosterone or estrogen) [c1, c2]. German forum users emphasize the need for medical supervision and laboratory monitoring [c4]. One female user with endometriosis was advised against continued use despite short-term symptom improvement [c1].
Scientific Sources
- Pregnenolone - an overview: Neurosteroid Effects including GABA-A, NMDA and Sigma-1 receptor interactions
ScienceDirect Topics Editorial (2023). ScienceDirect Topics (Elsevier)BLink - Pregnenolone: Reference Range, Neurosteroid Effects and Steroidogenesis
Lamkin Clinic Editorial (2023). Lamkin Clinic Clinical ReferenceCLink - Pregnenolone: Health Benefits, Side Effects, Uses, Dose and Precautions
RxList Medical Editors (2023). RxList.comCLink - Pregnenolon Dosierung Frau: So wirkt es gegen Wechseljahre
Menopause Zentrum Editorial (2024). Menopause ZentrumCLink - Bioidentes Pregnenolon als rezeptfreie 1%-Creme – St. Gallus Apotheke
St. Gallus Apotheke (2023). ApothekenwebseiteCLink - Legal status of Pregnenolone in EU – Reddit r/NootropicsDepot
Reddit Users r/NootropicsDepot (2023). Reddit r/NootropicsDepotDLink - Pregnenolone Rescues Schizophrenia-Like Behavior in Dopamine Transporter Knockout Mice
Takayanagi Y, Tsuchida H, Bhatt DL, et al. (2012). PLOS ONECPMID:23240026DOI - Pregnenolone can protect the brain from cannabis intoxication
Vallée M, Vitiello S, Bellocchio L, et al. (2014). ScienceCPMID:24385629DOI - Add-On Pregnenolone with L-Theanine to Antipsychotic Therapy Relieves Negative and Anxiety Symptoms of Schizophrenia: An 8-Week, Randomized, Double-Blind, Placebo-Controlled Trial
Kardashev A, Ratner Y, Ritsner MS (2018). Clinical Schizophrenia & Related PsychosesCPMID:26218236DOI - Pregnenolone as an adjunct to risperidone for treatment of women with schizophrenia: A randomized double-blind placebo-controlled clinical trial
Kashani L, Shams N, Moazen-Zadeh E, et al. (2017). Journal of Psychiatric ResearchCPMID:28688338DOI - Effect of Pregnenolone vs Placebo on Self-reported Chronic Low Back Pain Among US Military Veterans: A Randomized Clinical Trial
Naylor JC, Kilts JD, Shampine LJ, et al. (inkl. Marx CE) (2020). JAMA Network OpenCPMID:32119096DOI - Pregnenolonsulfat im Serum – ein Neurosteroid mit Wirkung im ZNS
IMD Berlin Laborärzte (2022). IMD Berlin FachinformationBLink - Steroidogenesis - Cholesterol to Pregnenolone and downstream pathways
ScienceDirect Topics Editorial (2023). ScienceDirect Topics (Elsevier)BLink - Pregnenolone - Wikipedia: Biosynthesis and metabolism
Wikipedia Contributors (2024). WikipediaCLink - Neurosteroids and GABA-A Receptor Function
Belelli D, Lambert JJ, Peters JA, et al. (2011). Frontiers in EndocrinologyBDOI - Proof-of-Concept Trial with the Neurosteroid Pregnenolone Targeting Cognitive and Negative Symptoms in Schizophrenia
Marx CE, Keefe RS, Buchanan RW, et al. (2009). NeuropsychopharmacologyAPMID:19279571DOI - Pregnenolone and L-theanine augmentation for schizophrenia and schizoaffective disorder targeting negative and anxiety symptoms
Ritsner MS, Bawakny H, Kreinin A (2014). Clinical Schizophrenia & Related PsychosesAPMID:21756978DOI - A Randomized, Double-Blind, Placebo-Controlled Trial of Pregnenolone for Bipolar Depression
Brown ES, Park J, Marx CE, et al. (2014). NeuropsychopharmacologyAPMID:24917198DOI - Pregnenolone for cognition and mood in dual diagnosis patients
Osuji IJ, Vera-Bolaños E, Carmody TJ, et al. (2010). Psychiatry ResearchAPMID:20493557DOI
Community Sources
Storage
Unopened
Store cool (15–25 °C), dry, and protected from light.
Opened
Keep tightly closed; avoid moisture and direct sunlight.
Notes
Pregnenolone is light-sensitive and may degrade to inactive oxidation products if stored improperly. Refrigeration of capsule formulations is not necessary but is acceptable.