Pregnenolone is marketed for its ability to enhance memory and brain function, among other claims. Before popping pills, make sure you're aware of pregnenolone side effects. This supplement may affect endocrine function and aggravate hormone-sensitive disorders.
Little is known about the long-term safety and effectiveness of pregnenolone, a steroid hormone. The U.S. Food & Drug Administration (FDA) warns that steroids or steroid-like substances carry serious adverse effects ranging from acne and hair loss to strokes and heart attacks.
How Does Pregnenolone Work?
Health stores promote pregnenolone as a natural brain-enhancing formula. Some athletes take this supplement to keep their hormones in balance following the use of anabolic steroids.
What you may not know is that your body produces pregnenolone naturally, explains the United States Anti-Doping Agency (USADA). This hormone is released by the adrenal glands and serves as a precursor to all steroid hormones, including testosterone, estrogen and cortisol.
Pregnenolone is also available in supplement form. According to PeaceHealth System Services, pregnenolone supplement formulas are marketed in amounts of 10 to 30 milligrams, but little is known about their safety and the appropriate dosage for humans.
The human body produces pregnenolone from cholesterol. This hormone, though, is also produced in the spinal cord, which may explain its effects on the brain. A December 2014 review published in the International Journal of Inflammation, Cancer and Integrative Therapy notes that pregnenolone supports the formation of new neurons. Additionally, it plays a role in brain plasticity and protects the nervous system.
Potential Health Benefits of Pregnenolone
Pregnenolone is promoted as a cure-all. Supplement manufacturers say that it slows down aging, boosts hormone production, increases energy levels and may prevent or treat medical conditions. Unfortunately, there is little evidence to support these claims, notes USADA. As with most supplements, the opinions are mixed.
The International Journal of Inflammation, Cancer and Integrative Therapy review, for example, states that pregnenolone balances GABA and glutamate levels in the brain, protecting the nervous system. GABA, which stands for gamma-Aminobutyric acid, is a neurotransmitter that reduces or inhibits nerve impulses, increasing feelings of calmness. Glutamate, a key neurotransmitter, has an excitatory action on nerve cells and regulates the nervous system.
Read more: 8 Ways to Keep Your Brain Sharp as You Age
Furthermore, pregnenolone may help repair damaged or degenerated neurons and aid in the treatment of Alzheimer's disease. Some studies suggest that it may also slow the progression of Parkinson's disease, states the International Journal of Inflammation, Cancer and Integrative Therapy review.
This steroid hormone also appears to have beneficial effects on cancer patients. A review published in Oncology Letters in August 2014 suggests that it may induce glioma cell death. Gliomas are malignant tumors that affect the brain and spinal cord.
There might also be an association between pregnenolone and breast cancer, according to a January 2019 review in Molecular Reproduction and Development. As the researchers note, this hormone may inhibit the proliferation of cancer cells and aid in the treatment of breast and ovarian cancers. Note that most studies have been conducted on animals or in vitro (a lab-controlled environment), so their findings may not apply to humans.
Pregnenolone Side Effects
Despite its potential health benefits, pregnenolone may not be safe or effective. Currently, it's classified as an unapproved new drug by the FDA, points out USADA. Topical products containing pregnenolone and other hormones lack scientific evidence, states the FDA.
PeaceHealth System Services explains that pregnenolone side effects may include changes in the menstrual cycle due to hormonal imbalances. Additionally, this supplement may worsen seizures and aggravate breast or prostate cancer. These claims contradict the findings reported in Molecular Reproduction and Development, so it's difficult to draw a definite conclusion.
As discussed earlier, bodybuilders and other athletes often use steroids or steroid-like substances for enhanced performance. Some formulas contain pregnenolone.
The FDA warns that bodybuilding products containing these compounds carry serious health risks. Although it doesn't mention pregnenolone in particular, it states that hormone formulas may cause hair loss, depression, behavioral changes and acne. Kidney damage, stroke and cardiovascular problems are all potential side effects.
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Excela Health notes that steroid hormones are a double-edged sword and that it's unclear whether or not pregnenolone is safe in the long run. So far, research confirms that pregnenolone may reduce the sedative effects of Valium and other benzodiazepines. The best thing you can do is to consult a health care provider. Your doctor may recommend a safer alternative.
- USADA: "Pregnenolone: What You Need to Know"
- PeaceHealth System Services: "Pregnenolone: How It Works"
- Human Metabolome Database: "Showing Metabocard for Pregnenolone"
- International Journal of Inflammation, Cancer and Integrative Therapy: "The Role of Pregnenolone in Inflammatory Degenerative Brain Disease"
- U.S. National Library of Medicine: "Gamma-Aminobutyric Acid"
- University of Bristol: "Glutamate Receptors"
- Oncology Letters: "Pregnenolone, a Cholesterol Metabolite, Induces Glioma Cell Apoptosis via Activating Extrinsic and Intrinsic Apoptotic Pathways"
- Mayo Clinic: "Glioma"
- Molecular Reproduction and Development: "Pregnenolone as a Potential Candidate for Hormone Therapy for Female Reproductive Disorders Targeting ERβ"
- FDA: "CFR - Code of Federal Regulations Title 21 — Drugs for Human Use"
- FDA: "Caution: Bodybuilding Products Can Be Risky"
- Excela Health: "Pregnenolone"
- PeaceHealth System Services: "Pregnenolone: Side Effects"