O-304 (ATX-304, OS-01) – High Purity Research Molecule (150 MG)

What Is ATX-304 (O-304)?

O 304 atx 304 os 01 dosage, also marketed under its earlier research name O-304, is a synthetic small molecule and pan-AMPK activator, meaning it activates adenosine monophosphate-activated protein kinase broadly across tissue types (liver, skeletal muscle, adipose tissue and cardiovascular tissue), rather than in one localised pathway. AMPK is often described as the cell’s energy sensor: when energy runs low, it switches on fat-burning and glucose-uptake processes and dials down energy-expensive synthesis.

Key identifiers:

• CAS number: 1261289-04-6
• Class: orally available, peripherally restricted, pan-AMPK and mitochondrial activator
• Developer: Cambrian Bio (clinical development), building on earlier academic AMPK research
• Also sold as: O-304 (the compound’s earlier research designation, still used by reagent suppliers and some UK retailers)

Important distinction: research chemical vs. clinical trial drug. ATX-304 is simultaneously being developed as an investigational pharmaceutical (in a Phase 1b trial for prediabetic obesity, as of mid-2026) and sold, separately, as an unregulated “research chemical” in capsule form by UK sports-supplement retailers. These are not the same regulatory pathway, and a capsule bought online has not been through the manufacturing, purity or safety oversight that the clinical-trial material has.

What the Research Actually Shows

Published research on ATX-304 is stronger and more recent than most compounds covered in this series, but it’s worth being precise about what it actually demonstrates:

• A peer-reviewed mouse study (Journal of Clinical Investigation Insight, April 2025) found ATX-304 reduced body fat mass, lowered blood cholesterol, and reduced liver steatosis and fibrosis progression in a model of MASLD (metabolic dysfunction-associated steatotic liver disease), by shifting liver metabolism away from fat synthesis and toward fat oxidation.
• A separate mouse and cell-culture study examined ATX-304’s protective effect against cisplatin-induced acute kidney injury, again via metabolic switching in kidney tubular cells.
• A Phase 1b human trial, presented at the American Diabetes Association’s 2026 Scientific Sessions, is investigating ATX-304 in prediabetic obese participants. This is an early-phase safety and tolerability trial, not a completed efficacy study, and results were being presented as a conference poster rather than published as a full peer-reviewed paper at the time of writing.

This is a genuinely more advanced evidence base than most compounds in this space. But it’s specifically about metabolic disease, fatty liver, prediabetes and obesity. It is not evidence for the “HPTA axis modulation” or “hormonal balance” framing that some UK retailers attach to it.

O-304, ATX-304, OS-01 Price: What UK Listings Actually Show

Checking O-304 ATX-304 price listings directly: one UK sports-supplement retailer (Cross The Limits) sells X-LAB O-304, 25mg capsules, 60 units, for £58.20, describing it as ≥98% HPLC-verified purity with a stated CAS number matching the genuine compound. Separately, research-chemical suppliers outside the UK have listed raw ATX-304 powder at bulk quantities (10g) alongside batch purity figures around 99.67%.

Price alone doesn’t tell you much here. What matters more is which of the two supply chains you’re buying from, an unregulated grey-market capsule product, or a documented research-chemical powder with a batch COA, since neither is the same as the clinical-trial-grade material being tested in the actual Phase 1b study.

ATX-304 Dosage: Why No Consumer Dose Exists

This is the most important section for anyone searching ATX-304 dosage or O-304 dosage. There is currently no completed, published human dose-finding study for ATX-304. The only human trial underway is an early-phase safety and tolerability study in a clinical-trial setting, with dosing controlled by trial protocol, medical oversight and regulatory approval, not a figure that translates to a retail capsule.

Some UK retailers selling this compound as a capsule product don’t state a specific dose or serving protocol at all, instead directing buyers to “consult with a specialist,” while still using language like “HPTA Axis Modulator” that implies a therapeutic hormonal effect not established in the actual published research on this compound. That’s worth being clear-eyed about: a product description built around unproven hormonal claims, paired with no dosing information and a disclaimer aimed at “researchers over 21,” is not the same thing as a compound with an established consumer use case.

If you’re a laboratory researcher working with ATX-304 in a cell-culture or animal-model context, your exposure parameters should come from your own study design and the published primary literature (the JCI Insight paper is a reasonable starting point), not from a supplement retailer’s serving suggestion.

What to Check Before You Buy

1. Confirm which compound you’re actually getting. ATX-304 and O-304 are the same molecule under different names (CAS 1261289-04-6); OS-01 is unrelated. Don’t let a listing conflate them.
2. Batch-specific COA with HPLC purity and identity confirmation
3. Accurate claims. The genuine evidence base concerns metabolic disease, fat mass, cholesterol and liver fibrosis in animal models, plus an early-phase human safety trial. Claims about hormonal or testosterone-axis effects aren’t supported by the published literature on this specific compound.
4. Research-use framing, with no dosing protocol presented as established
5. UK company registration and contact details clearly stated

Supplier Comparison at a Glance

Frequently Asked Questions

Is ATX-304 the same as O-304?
Yes. O-304 was the compound’s earlier research designation; ATX-304 is the name used in its current clinical development by Cambrian Bio. Some UK retailers still use the O-304 name.

O 304 atx 304 os 01 dosage approved as a medicine?
No. It’s an investigational drug in early-phase (Phase 1b) human trials. It has no approved medicinal status anywhere, and is not an approved treatment for obesity, diabetes or any other condition.

Does ATX-304 support “hormonal balance” or the HPTA axis?
This isn’t supported by the published research on ATX-304, which concerns AMPK activation, fat metabolism and liver disease markers, not the hypothalamic-pituitary-testicular axis specifically. Treat that kind of claim with scepticism.

Is OS-01 the same thing?
No. OS-01 is an unrelated topical peptide studied in skincare research. It shouldn’t be grouped with ATX-304/O-304.

Final Thoughts

ATX-304 is a rare case in this space: a compound with genuine, recent, peer-reviewed animal data and an active human clinical trial behind it. That’s exactly why it’s worth being precise about what’s proven and what isn’t, rather than letting a retail listing borrow the credibility of the clinical programme while making claims the actual research doesn’t support.