In the early days of steroid research, folks in chemistry labs wanted to figure out what made hormones tick. They dug deep into cholesterol derivatives and stumbled onto compounds like 5A-Pregnan-3B-Ol-20-One. This wasn't just some minor backwater of molecular discovery — steroid biochemistry shaped medicine, sports, and even crime stories. The road to isolating and naming 5A-Pregnan-3B-Ol-20-One wound through the 1950s and 1960s, when scientists developed new methods to separate natural and synthetic steroids. Researchers saw that pregnane derivatives packed strong activity in animal studies and kept combing through urine and tissue extracts from people to map out each metabolite. Now, after years of characterizing its activity and behavior, this molecule stands out as a key intermediate in progesterone metabolism and a marker in endocrinology labs.
5A-Pregnan-3B-Ol-20-One, a pregnane-based steroid, often shows up as a creamy white powder that packs some serious scientific firepower. It belongs to the family of neurosteroids and fills an under-the-radar but influential role in cellular signaling. Technicians and scientists handle it for lab analysis, structure–activity research, and synthesis of more complex molecules. You won’t see it on regular pharmacy shelves, but endocrinology labs make regular use of this compound for reference standards or to study metabolic pathways. The diversity of its applications stretches from chemical synthesis schemes all the way to preclinical animal research on steroid signaling.
Holding 5A-Pregnan-3B-Ol-20-One in your hand, you find a solid with a melting point around 175-180°C. It barely dissolves in water but slides easily into organic solvents like chloroform or ethanol. The molecular formula is C21H36O2, with a molecular weight close to 320.5 g/mol. This compound stays relatively stable under cool, dry conditions. The structure comes from a four-ring system, classic for steroids, with hydroxyl and ketone groups at key spots on the backbone. This layout lets it slip into biological reactions involving steroid enzymes and cell membrane receptors. As for taste and odor — the less said, the better, since this isn’t something made for flavor or scent.
Labs who sell 5A-Pregnan-3B-Ol-20-One put out detailed specs for every batch. Purity clocking above 98% usually satisfies analytical and research uses; anything lower gets extra scrutiny. Labeling comes with safety warnings and recommendations for cold, dark storage in sealed containers. Each lot lists analytical results — NMR nuclear magnetic resonance data, mass spectrometry readouts, and melting points. Even a hint of impurity gets flagged because researchers want molecules that don’t throw off their results. Labels also point out the absence of lots of common contaminants like heavy metals, solvent residues, and microbial growth.
Manufacturing 5A-Pregnan-3B-Ol-20-One takes chemical know-how. Most often, synthesis starts from plant-sourced sterols such as diosgenin or stigmasterol, harvested from wild yams or soybeans. Chemists then wheel these raw materials through a series of reactions: oxidation, reduction, and selective hydrogenation. Protecting group strategies keep unwanted reactions at bay, especially around the sensitive hydroxy and ketone sites. The process doesn’t always finish in one pot, so there’s a lot of purification between stages — think repeated crystallization or chromatography columns that separate the right product from a crowd of look-alikes. Every synthesis run generates a mountain of quality data and a trail of solvent waste that needs safe disposal.
The backbone of 5A-Pregnan-3B-Ol-20-One invites targeted reactions at specific “hot spots” — mainly the C3 hydroxy and C20 ketone groups. Oxidizing the alcohol or reducing the ketone gives other biologically active steroids; attaching small functional groups like methyl or acetate at these positions changes the way the molecule behaves in living cells. Enzymes such as 3α- or 20α-hydroxysteroid dehydrogenases can transform it naturally, helping the body regulate steroid levels. In the lab, chemists use standard reagents or enzymes to generate analogs for pharmacological testing. These chemical tweaks supply material for new hypotheses in neuroscience and reproductive health as researchers map out which modifications flip biological switches.
You might run into this compound under a handful of different names, especially if you read old scientific papers. Synonyms include 5α-Pregnan-3β-ol-20-one, Pregnanolone, and sometimes simply 3β-Hydroxy-5α-pregnan-20-one. Casually, folks at the bench might call it “3β-hydroxy” or just pregnanolone, though that can spark confusion with isomers. Commercial catalogues often use a CAS number — 516-02-9 — for quick and unambiguous identification.
Handling 5A-Pregnan-3B-Ol-20-One makes safety a daily routine in the research setting. Wearing gloves, goggles, and lab coats prevents accidental skin or eye contact, while fume hoods control dust and vapor exposure. While acute hazard reports are mild compared to some chemicals, chronic exposure brings uncharted territory, so minimizing risk takes center stage. Facilities must store this powder away from heat, light, and moisture, keeping containers tight and secure. Transport paperwork identifies it as a research chemical to prevent mix-ups or misuse. Proper records limit diversion and help trace any supply chain hitches. Cleaning up after use takes a full sweep — no leftover powder should drift into shared lab spaces or contaminate sensitive experiments.
5A-Pregnan-3B-Ol-20-One finds its audience in several corners of science. Researchers track its role in the biosynthesis of steroid hormones and in diagnostics for endocrine disorders. Scientists studying the brain look at this molecule as a neuroactive steroid influencing anxiety, sleep, and seizure activity. Animal research probes its calming and protective effects — data sometimes guides development of drugs for epilepsy or panic disorder. Analytical chemists use it as a standard when validating steroid measurements in blood and urine. Pharmaceutical innovators need it to craft new molecules with precision effects on hormone signaling.
In the past two decades, more labs have focused on neurosteroids like 5A-Pregnan-3B-Ol-20-One for their ability to tune brain cell receptors, especially the GABA-A type. Research groups design animal tests that measure changes in behavior and seizure resistance after dosing. Molecular biologists dig into the enzymes that produce and break down this steroid, trying to understand how stress and disease alter its concentration. Medicinal chemists draw up new analogs in hopes of finding lead compounds for future tranquilizers or antidepressants. Patents and clinical trial reports start to mention this molecule more often as interest in natural brain modulators grows.
Animal studies using 5A-Pregnan-3B-Ol-20-One usually report a high safety margin, with most subjects tolerating moderate doses without obvious harm. Long-term exposure tests are rare, so a careful eye remains on reproductive, carcinogenic, and mutagenic risks. Many regulatory bodies treat these kinds of steroids with caution, requiring animal data before approving research or diagnostics. High doses or misuse could affect developing brains or fertility — risks that matter whenever research scales up to clinical trials. Toxicologists want more data before they can rule out chronic effects on liver, kidneys, and hormone systems. That’s why risk assessments stick to conservative guidelines and regular reviews.
Interest in 5A-Pregnan-3B-Ol-20-One keeps climbing as new findings link it to stress adaptation, sleep cycles, and brain resilience after injury. Drug developers hope that analogs based on this structure could treat disorders like epilepsy, PTSD, or insomnia with fewer side effects than existing drugs. The push for targeted brain medicine now includes neurosteroids as serious candidates for next-generation therapeutics. On the analytical side, the demand for clean standards in hormone measurement grows every year, fueled by sports testing, anti-doping, and personalized medicine. Researchers want to know exactly how this molecule changes with age, disease, and drug treatment, which means fresh studies and better technology for detection and analysis. Whether as a lab tool, a clinical candidate, or a biological probe, 5A-Pregnan-3B-Ol-20-One still draws the attention of scientists who want to get to the bottom of chemical control in human health.
5A-Pregnan-3B-Ol-20-One might sound like a scrambled chemistry formula, but this compound has a story woven into labs and clinics around the world. I’ve spent time around university researchers who often mention it by its other name: pregnanolone. They turn to it during long days trying to unravel how the brain manages stress or calms down after a riled-up moment. Pregnanolone belongs to a group of steroids called neurosteroids, found right inside the brain, not just somewhere in the bloodstream. These molecules carry more weight than most folks realize.
Scientists use pregnanolone for what it does to brain signals—it acts as a modulator, not a blunt hammer. It boosts the force of GABA, a brain chemical that settles nerves, brings quiet to racing thoughts, and sometimes makes a person drowsy. That means researchers often rely on it as a tool in animal studies when exploring pathways that might tie to anxiety, insomnia, or even seizures. From conversations with pharmacologists, it stands out that pregnanolone isn’t just background noise—it can actually flip switches on behavior and mood in lab animals.
Doctors and researchers flirt with its possible benefits, looking at how it might someday support humans. Most conversations I’ve had with psychiatrists point to a single idea: modern medicine is hungry for new answers to anxiety and depression, especially when regular pills leave people stuck. Some small clinical studies have tested pregnanolone for calming tough symptoms, though nobody sees it as a miracle fix just yet.
On the hormone front, pregnanolone is a key stop on the road from progesterone to other hormones like allopregnanolone, which pharmaceuticals are already testing to treat postpartum depression. By measuring pregnanolone in blood or spinal fluid, doctors get clues about hormone imbalances that may play into mood swings or neurological conditions. This kind of hormone detective work—measuring tiny shifts in these compounds—sometimes feels like peering into a foggy window, but for rare disorders like adrenal insufficiency, it’s a lifeline.
I remember a colleague struggling with side effects from traditional anxiety medication, getting nowhere. She asked about alternatives and laughed at the idea of “neurosteroids,” but beneath that skepticism, some hope sparked. The trouble is, turning compounds like pregnanolone into standard treatments isn’t just about proof of concept in a petri dish. Designers face issues with safety, dosing, unpredictability, and even the cost of turning these fragile molecules into pills or injections that don’t fall apart before reaching the bloodstream.
Researchers hunt for ways to deliver pregnanolone so it reaches the brain without causing sleepiness or confusion. I’ve seen grant proposals packed with new delivery systems—slow-release injectables or dissolving films—since the brain’s own chemistry can shift so quickly. Pharmacologists remain cautious, and so do regulators. Instead of treating these neurosteroids like magic bullets, they watch them for clues about brain resilience, the ebb and flow of everyday stress, and why some people bounce back from trauma while others don’t.
Today, 5A-Pregnan-3B-Ol-20-One mostly helps scientists explore big questions in neuroscience and endocrinology. Its story is only getting started, but it already encourages experts to think wider than old-school chemicals and pay closer attention to the brain’s own homegrown controls. Solutions may not be overnight, but digging deeper into neurosteroids could nudge future breakthroughs closer.
In the lab, 5A-Pregnan-3B-Ol-20-One is a mouthful, but people who work with steroids or neuroactive chemicals usually just call it “pregnanolone” or pick a nickname. The moment you start handling this molecule, purity steps up as a real concern. Low-grade materials turn experiments into nightmares, slow down drug development, and pump up costs for absolutely no good reason.
From my time bouncing between academic research and startup contract labs, I’ve seen countless batches stall projects because batches came in below 98% assay. Reagents with extra byproducts create serious headaches on chromatographs, and sometimes, the difference between a smart scientist and an average one lies in how picky you get about these numbers.
Anyone curious about working with 5A-Pregnan-3B-Ol-20-One starts by checking the certificate of analysis. Top-quality product runs at 97% purity or higher, often reaching 98–99%, confirmed by HPLC (High Performance Liquid Chromatography) or GC (Gas Chromatography) against reference standards. These certificates detail assay, melting point, optical rotation, moisture content, and usually residual solvent analysis.
Melting point tells a lot—this compound usually sits around 120–123°C, depending on crystal form. Optical rotation numbers also deserve a look if you care about stereochemistry. Water content, checked by Karl Fischer titration, should stay under 0.5% because water invites breakdown. Residual solvents like methanol, DCM, or hexane need to be less than a few hundred ppm. If a supplier shrugs off providing these numbers, turn and walk the other way.
Buyers from universities and industry alike treat 5A-Pregnan-3B-Ol-20-One as more than chemical inventory. Many researchers use it to model neurological disorders or to explore its potential in mental health drug pipelines. Subtle impurities, even in trace amounts, can send animal data sideways or cloud up downstream syntheses.
Take this from experience: a batch at 95% with mystery peaks ends up costing more in troubleshooting than buying the good stuff up front. If you’re setting up experiments involving endogenous steroid pathways, purity spares you piles of wasted time and damaged credibility.
A solid supplier doesn’t only send along purity as a catch-all number. They’ll show their method, chromatograms, and preferably list individual impurities. Nitrogen, sulphur, and heavy metals warrant testing if you’re pushing toward pharma standards. The more details, the less your team backtracks later. It comes down to trust—every number should check out, every impurity accounted.
Packaging details also matter. This steroid often arrives as a white crystalline powder, usually in amber glass vials or PTFE-sealed bottles. Even minor exposure to air or heat kicks degradation into gear and leads to off-notes in results. Once, I received a shipment in a simple plastic jar—half the batch clumped, and the smell hit something fierce. Never again.
If stuck with a questionable batch, running another round of recrystallization sometimes helps, but it’s no cure for real contamination. The best fallback involves validating against a reference standard and keeping those chromatograms. Sourcing from vetted suppliers, checking batch histories, and pressing for full documentation turn what could be a risky purchase into a reliable routine.
Other labs pool resources, sharing vials and pooling data on suppliers. That old network effect proves invaluable over and over. Sometimes the best lessons come from community blacklists and whispers passed in conference halls.
It’s more than ticking a box or passing inspection. The ripple effect of high or low specs for 5A-Pregnan-3B-Ol-20-One turns up in every replicate, every clinical trial, and every decision a team makes down the line. One good sample saves months. Every outlier batch—every time a chromatogram looks suspicious—means money and trust lost.
Anyone who has ever worked in a lab knows that the way you store a chemical shapes its entire future. Years ago, back in my days prepping stockrooms, I learned quickly how easy it is to ruin perfectly good material because of a lazy storage decision. 5A-Pregnan-3B-Ol-20-One isn’t any less fragile than other sensitive organic compounds, despite its intimidating name. Sometimes people get too caught up in chasing their next result and overlook these basics, but sloppiness in storage turns to wasted product and lost money before you know it.
The real enemy here is heat and moisture. If you let your 5A-Pregnan-3B-Ol-20-One sit at room temperature on an open shelf, degradation won’t take long to show itself—at least, not if you plan on working with it more than once or twice. Every experienced chemist I know takes storage temperature seriously, usually aiming for an environment not much warmer than a refrigerator. Around 2-8°C works well. When I trained new lab assistants, I had them run temperature logs daily, just to keep failures down. Letting temperatures creep up, even a little, pushes many steroidal substances to break down, and then you’re left guessing if your next batch will react the same way.
Nothing frustrates me more than walking into a facility and seeing expensive product in loose jars. Open to the air, powders like this pick up moisture fast, and they also risk minor oxidation. Best bet: amber glass vials or opaque containers with screw tops fit tight. You want that material dry and out of the light. Even ambient lab lighting slowly triggers photo-degradation. I’ve seen batches stored carelessly that went yellow in a month because a skylight bathed them for hours a day. Keeping materials in the original container from the supplier often saves a lot of headaches.
Cross-contamination turns hard work into a guessing game. In my early days, I watched a coworker dip spatulas from one bottle to another, figuring ‘it’s all going to be used up anyway’. The next time quality control came through, we had a full shelf flagged and trashed. Scoops and tools should be clean, dry, and used for just one substance at any given time. Small things matter.
The old-timers I admired most taught me: never pull your entire stock out for routine use. Transfer small portions as needed and return the rest to storage right away. Every time powder sits at room temperature or someone opens the main supply, risk creeps up.
Proper labeling helped me sleep at night. I clearly mark every bottle with received and opened dates. Without tracking, mistakes slip into daily operations. A solid logbook or digital inventory keeps surprises—and losses—to a minimum.
The real trick is sticking to habits—cool, dry, sealed, low exposure. If you handle 5A-Pregnan-3B-Ol-20-One this way, waste drops, surprises fade, and every ounce of product actually counts. Good storage isn’t glamorous, but it protects time, money, and research work every single day.
5A-Pregnan-3B-Ol-20-One, better known to some as allopregnanolone, pops up in conversations about brain health and steroid hormones. Researchers and supplement enthusiasts chat about its links to stress balance, mood, and more. Yet, outside clinical environments, there’s a shaky understanding of how to use it responsibly. Few products exist for personal use, and most people investigating it have to depend on research data or paywall-guarded academic journals.
Most studies on 5A-Pregnan-3B-Ol-20-One involve lab animals or small-scale clinical efforts. In these cases, dosing gets measured precisely, often through injections or infusions. Dosages in research vary widely — for example, in neurosteroid studies with humans, investigators have delivered up to 10 mg intravenously. For animal research, doses swing from micrograms to several milligrams per kilogram. Translating those numbers for an ordinary human's daily use isn’t straightforward. Variables like absorption, metabolism, and method of delivery muddy the waters. It’s a far cry from buying vitamin C at a grocery store where the label tells you what to do.
To find best practices, people sometimes lean into anecdotal chatter from forums or unregulated sources. That’s risky business. Without professional input, dosing by guesswork opens the door to side effects like heavy sedation, hormonal imbalance, or even dependence. This particular compound works alongside GABA in the brain, influencing everything from sleepiness to emotional steadiness. Overdoing it could drop someone into a mental fog or worsen pre-existing conditions. Unlike water-soluble supplements, neuroactive steroids can linger and pile up unnoticed.
I’ve seen people try to hack their well-being with whatever they can find online. It sometimes leads to more confusion, and in tricky cases, a trip to the ER. Doctors typically steer clear of offering blanket statements on these rare compounds. Honest ones will talk about the lack of established safety profiles and the absence of regulatory oversight. The only times I’ve witnessed this substance under professional care involved hospital settings, controlled dosing, and follow-up tests to monitor side effects.
For those set on pursuing 5A-Pregnan-3B-Ol-20-One, the responsible approach calls for medical collaboration. Pharmacies sometimes compound related substances for legitimate uses like seizures or rare hormonal problems, but every step involves oversight. Self-experimentation carries risks everyone ought to weigh seriously. Regulators haven’t approved over-the-counter versions, so black market or gray market sources lack purity assurances, contaminant checks, or clear instructions.
Groups working in neurosteroid research push for more studies. It helps to talk openly about the knowledge gaps, potential long-term consequences, and ethical ways to expand access to responsible clinical trials. Better funding and transparent patient-reported outcomes could clarify dosing and side effect questions. Instead of wandering in the dark, the conversation shifts toward empowered decision-making backed by data, not promises.
For now, anyone looking into 5A-Pregnan-3B-Ol-20-One should start with tough questions: Is this the best route for my needs? Who do I trust for sound advice? Information alone doesn’t equal understanding, and a few milligrams of uncertainty can tip the balance in unexpected ways.
Plenty of chemicals sound like gibberish until someone makes sense of them, and 5A-Pregnan-3B-Ol-20-One is a prime example. It looks like any other powder from the outside. Those three lines of its name barely give away the real story. If you ask people who depend on accurate information—lab techs, pharmacologists, or even hobbyists—they’ll tell you trust doesn’t come in the bottle; it shows up in documentation. Enter the certificate of analysis, or COA.
My own run-ins with these sorts of compounds date back to my college lab days. I got burned once by an untested reagent that contaminated half a semester’s work. That’s what keeps me skeptical. Having a COA on hand means I get answers: Was it stored cold? Who did the tests? Is it 98% pure, or is the purity closer to a quarter bag of flour mixed with sand?
It’s not only about raw data. Let’s get practical. Researchers using 5A-Pregnan-3B-Ol-20-One for neurosteroid studies bank their long days on purity and identity. Wrong numbers wreck results, waste budgets, and at worst, threaten safety. A trustworthy COA outlines testing by chromatography, melting point, elemental analysis. Real details, not marketing fluff.
Labs often treat that sheet as a must-have because so much can go wrong. Too many suppliers operate on faith or bulk traditions. Scientists, though, want specifics. If I were buying something obscure like this, I’d need its COA in hand before even opening the box. The document covers heavy metals, solvents left behind, and even water content. After all, impurities in a chemical structure can sneak up in unexpected ways.
A few years ago, the research world saw a scandal involving mislabeled research chemicals, and people learned the hard way that someone’s word isn’t enough. There are suppliers who sell without documentation. Sometimes they exist in a gray area online, or they sell on reputation in tiny research circles. Relying on these sellers sets up any study for failure. Worse, it puts entire teams at risk if hazardous residues are left unidentified.
Ask anyone in pharmaceutical development, and they’ll say the same thing—cutting corners with documentation ends actual projects. Grants dry up when the evidence points to contaminated or mislabeled compounds. Even testing equipment can suffer, gumming up chromatography columns and wasting thousands of dollars. Sometimes, legal obligations force labs to keep proof of documented analysis on hand for audits or quality systems.
The solution looks pretty clear. Demand the COA before money changes hands. Anyone selling scientific chemicals should expect this as business as usual. Reputable sellers always attach a COA as a PDF or stick a printed page in the shipment. If a supplier hesitates or tries to sidestep the request, it’s a red flag worth heeding.
Quality checks are a fact of life, not a luxury, for people working with specialized compounds. Pushing for a COA pushes everybody involved to do things right. This isn’t just paperwork; it’s the reason people can trust their results—or even trust that the stuff in the bottle is what the label promises.
| Names | |
| Preferred IUPAC name | (3β)-Pregnan-3-ol-20-one |
| Other names |
Pregnanolone 5α-Pregnan-3β-ol-20-one 3β-Hydroxy-5α-pregnan-20-one |
| Pronunciation | /ˈfaɪv.eɪ.prɛɡ.næn.ˈθriː.biː.ɒl.twɛnti.oʊn/ |
| Identifiers | |
| CAS Number | 516-55-2 |
| 3D model (JSmol) | `/4H+VGXW1DPFZTQX-UOHGRNSCSA-N/O` |
| Beilstein Reference | 2467646 |
| ChEBI | CHEBI:16763 |
| ChEMBL | CHEMBL173859 |
| ChemSpider | 123374 |
| DrugBank | DB02509 |
| ECHA InfoCard | 100.202.163 |
| EC Number | 1.1.1.146 |
| Gmelin Reference | 534486 |
| KEGG | C02136 |
| MeSH | D004649 |
| PubChem CID | 13353 |
| RTECS number | GU4050000 |
| UNII | A414P27P3S |
| UN number | UN2811 |
| Properties | |
| Chemical formula | C21H36O2 |
| Molar mass | 316.488 g/mol |
| Appearance | White solid |
| Odor | Odorless |
| Density | 1.04 g/cm3 |
| Solubility in water | Insoluble in water |
| log P | 2.87 |
| Vapor pressure | 2.27E-07 mmHg |
| Acidity (pKa) | 13.5 |
| Basicity (pKb) | 2.92 |
| Magnetic susceptibility (χ) | -85.0e-6 cm^3/mol |
| Refractive index (nD) | 1.543 |
| Dipole moment | 2.94 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 322.6 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -697.6 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -9807 kJ/mol |
| Hazards | |
| Main hazards | May cause respiratory irritation. May cause eye irritation. May cause skin irritation. |
| GHS labelling | GHS07, GHS08 |
| Pictograms | `⛔️☠️⚠️` |
| Signal word | Warning |
| Hazard statements | H315: Causes skin irritation. H319: Causes serious eye irritation. H335: May cause respiratory irritation. |
| Precautionary statements | P261, P264, P272, P280, P302+P352, P305+P351+P338, P362+P364, P501 |
| NFPA 704 (fire diamond) | 1-1-0 |
| Flash point | 79.6°C |
| LD50 (median dose) | 1017 mg/kg (rat, oral) |
| NIOSH | PJ9410000 |
| PEL (Permissible) | 3 mg/m3 |
| REL (Recommended) | 2 mg |
| Related compounds | |
| Related compounds |
5α-Dihydroprogesterone Allopregnanolone Isopregnanolone Pregnanolone Epi-allopregnanolone |
