Pregnenolone Capsules

Overview of Pregnenolone Capsules

Dosage Strengths of Pregnenolone Capsules

5 mg
10 mg
25 mg
50 mg
100 mg

General Information

Pregnenolone, also referred to as 5-pregnenolone or pregn-5-en-3β-ol-20-one, is a 21-carbon endogenous steroid.1 It is biosynthesized from cholesterol and is a precursor and a metabolic intermediate to the gonadal steroid hormones and adrenal corticosteroids, including estrogen, progesterone, testosterone, dehydroepiandrosterone (DHEA), cortisol, and cortisone.12 Pregnenolone is also biosynthesized from cholesterol within the central nervous system and the peripheral nervous system, which lends its classification as a neurosteroid.3

Synthetic pregnenolone is sold as a supplement. It is not FDA-approved and there is little data on the safety and efficacy of long-term use of pregnenolone. Pregnenolone should be taken under the supervision of a physician.

Preliminary research shows that pregnenolone enhances learning and memory and can even reverse memory deficits in rodents.45 However, human studies have produced contradictory results.5

Initial research shows that pregnenolone has significant anti-inflammatory properties.6

Dysregulation of pregnenolone has been observed in patients with schizophrenia, bipolar disorder, depression, and Alzheimer’s disease.78910 This data leads researchers to look at the potential of exogenous pregnenolone to treat patients with these conditions.

Early human trials show that pregnenolone significantly improves SANS scores in patients diagnosed with schizophrenia compared to placebo.4 Early human trials suggest that pregnenolone may improve depressive symptoms in patients diagnosed with bipolar disorder.11

Mechanisms of Action

Pregnenolone plays a crucial role in processes throughout the body, including neurogenic growth.12 It’s role as a substrate makes it crucial in the production of steroid hormones and adrenal corticosteroids and therefore highlights its importance in the regulation of bodily processes. It is also a precursor to other neurosteroids, including pregnenolone sulfate and allopregnanolone.1314

As a neurosteroid, pregnenolone modulates neurotransmission via the neuronal membrane and provokes structural changes in neurons and in astrocytes.15 Neurosteroids, including pregnenolone, have a modulating effect on neural excitability and synaptic plasticity.12 Pregnenolone is an excitatory neurosteroid and can act as an allosteric modulator of neurotransmitter receptors, such as GABAA, NMDA, and sigma receptors.161718

Pregnenolone is a ligand of the microtubule-associated protein 2 (MAP2) for the stimulation of the polymerization of microtubules.19 It is also a N-methyl-d-aspartate (NMDA) NMDA ligand.16 It is a negative allosteric modulator of the GABAA receptor and the CB1 receptor, and is an agonist of the σ1 receptor and the pregnane X receptor.202122232425


Pregnenolone can be administered orally, subcutaneously, intravenously, intranasally, and topically/transdermally.4261327 Oral pregnenolone has high metabolism and low bioavailability.28 It is lipophilic and readily crosses the blood brain barrier.429

There is very limited data on the pharmacokinetics of exogenous pregnenolone. Oral pregnenolone is metabolized in preference to allopregnanolone, rather than other hormones biosynthesized from pregnenolone substrate, such as cortisol or DHEA.43014 One study observed that three hours after oral consumption of a single dose of 400mg of pregnenolone, pregnenolone serum levels increased by approximately 60%. Two hours after this dose, allopregnanolone serum levels tripled.14 An earlier study shows that a single oral dose of 175mg of pregnenolone approximately doubled pregnenolone serum levels over the course of four to eight hours.314

One study observed the effects of exogenous pregnenolone on patients diagnosed with schizophrenia or schizoaffective disorder. Participants were given eight weeks of oral pregnenolone--with an escalating fixed-dose approach, where patients took 500mg per day for the last four weeks. Serum levels of pregnenolone and certain downstream metabolites were measured. Treatment with oral pregnenolone elevated pregnenolone serum levels fourfold, pregnenolone sulfate serum levels tripled, and allopregnanolone serum levels increased fivefold. Furthermore, treatment with oral pregnenolone elevated progesterone serum levels more than fourfold and DHEAS levels by approximately 16%. In this study, exogenous pregnenolone did not increase serum levels of testosterone, free testosterone, cortisol, DHEA, estradiol, or androstenedione levels.4


Take this medication by mouth daily unless directed otherwise by your healthcare provider. If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Take your next regularly scheduled dose. Do not take two doses at the same time.

Synthetic pregnenolone has the potential to be converted to cortisol and therefore may cause or exacerbate feelings of anxiety and may affect sleep if taken in the afternoon or at night.3233

Contraindications / Precautions

There is little data on the long-term effects of oral pregnenolone. Since pregnenolone is a precursor to estrogen, its use is contraindicated in patients diagnosed with or at risk for estrogen-dependent cancers, including breast, endometrial, ovarian, and prostate.34353637 Research shows that high levels of estrogen may also contribute to a number of health concerns and conditions, including endometriosis, cardiovascular disease, lupus erythematosus, neurodegenerative diseases like Alzheimer’s, and seizure disorders.383940414243

High levels of DHEA, a pregnenolone-derived neurosteroid, might worsen psychiatric disorders and increase the risk of mania in people who have mood disorders. Pregnenolone is contraindicated in patients taking DHEA, patients with higher than normal levels of DHEA, and patients who have been diagnosed with or who are at risk for psychiatric disorders and mania.4445

Pregnenolone may cause rapid heart beat.46 Pregnenolone is contraindicated in patients diagnosed with or at risk for arrhythmia.

Pregnenolone is contraindicated in patients diagnosed with or at risk for liver or kidney disease.

Smoking increases the risk of cardiovascular disease in women taking menopausal hormone therapy.4748 Smoking increases testosterone levels in men by as much as 15% compared to patients who do not smoke.49 Although more research is needed to fully understand how smoking impacts hormone levels, it is recommended that patients interested in taking pregnenolone should cease smoking before taking pregnenolone.48

Pregnancy / Breastfeeding

There is little data on the use of pregnenolone tablets in women who are pregnant or breastfeeding. As such, it is difficult to determine a drug-associated risk of adverse developmental outcomes. Women who are pregnant or breast-feeding should avoid using this product.


Pregnenolone counteracts the sedative effects of diazepam (Valium).50 Although more research is needed, this suggests that it may also counteract the sedative effects of all benzodiazepines. Furthermore, pregnenolone has been shown to produce an anxiogenic response in mice.51

Pregnenolone inhibits the GABAA receptor and may also inhibit drugs used to increase GABA activity, such as Neurontin for epilepsy and depression.46

Pregnenolone is contraindicated in patients taking DHEA. High levels of DHEA might worsen psychiatric disorders and may increase the risk of mania in people who have mood disorders.4445

There is not enough data on the concurrent use of pregnenolone and other hormone therapies. Since pregnenolone is the precursor to steroid hormones, it may augment the effects of hormone therapy and may increase the risk and severity of side effects of hormone therapy.

Alterations in levels of downstream pregnenolone metabolites, such as estradiol, could impact the efficacy of oral contraceptives.4

Adverse Reactions / Side Effects

There is very little data on the effects of long-term use of pregnenolone. Limited studies where pregnenolone is administered for four to twelve weeks show that pregnenolone is well-tolerated.52114 One study recorded mild side effects, including mild restlessness, mild muscle pain/stiffness, and mild cold extremities.4

Pregnenolone may cause side effects similar to those known for testosterone, including acne, hair loss, aggressiveness, irritability, increased levels of estrogen, and hair growth on the face in women. In some cases, which would call for immediate termination of use, it may cause rapid heartbeat, blurred vision, and dizziness.46 This list may not include all possible adverse reactions or side effects.


Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.

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