ATX-304, also called O-304, is an investigational oral small molecule AMPK activator—not a peptide. It is being studied for obesity and cardiometabolic disease, but it is not FDA-approved, and Chia does not sell it. Buying research chemicals for personal use carries real quality, dosing, and safety risks.
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See if you qualify →What are the quick facts about ATX-304?
ATX-304 is a clinical-stage metabolic drug candidate. The clearest patient answer is that it is not a peptide, not an approved prescription drug, and not something Chia offers.
ATX-304 is also known as O-304
ATX-304 is also referred to as O-304 in scientific and research discussions. Some online sellers and blogs may also use OS-01, but the key point is the same: these names refer to an investigational metabolic compound, not an approved treatment.
It is an oral small molecule, not a peptide
Peptides are short chains of amino acids. ATX-304 is described by its developer as a peripherally restricted oral small molecule that activates the AMPK network, which is a cellular energy-sensing pathway 1.
It is investigational and not FDA-approved
Cambrian Bio lists ATX-304 as a Phase 2 drug candidate for obesity and obesity-associated diseases 1. A Phase 2 listing means it is still being studied; it does not mean the FDA has approved it for weight loss, fat loss, prediabetes, type 2 diabetes, MASLD, or MASH.
Human evidence is early and still limited
Company-reported Phase 1b data described 23 adults with obesity and prediabetes who received ATX-304 400 mg once daily for 8 weeks, followed by an optional open-label extension 2. That is useful early research, but it is too small and too short to prove long-term weight-loss benefit or long-term safety.
What is ATX-304?
ATX-304 is being studied as an AMPK activator for metabolic disease. In plain English, it aims to shift cells toward using energy, but whether that leads to safe, durable health outcomes in people is still under study.
Why people call it an AMPK activator
AMP-activated protein kinase, or AMPK, is often called a cellular fuel gauge. When energy demand rises, AMPK helps cells increase glucose uptake, fatty acid oxidation, and mitochondrial energy activity 3.
A preclinical ATX-304 paper reported that the compound increased AMPK activity by suppressing dephosphorylation of threonine 172, a key regulatory site for AMPK activation 3. That mechanism is promising, but it is not the same as proven patient benefit.
Why exercise mimetic is an early research term, not a proven outcome
The phrase “exercise mimetic” means a drug may copy some cell-level signals seen with exercise, such as higher glucose uptake or mitochondrial respiration. Cambrian Bio states that Phase 2 studies are planned to test exercise-mimetic effects, muscle function, lipid metabolism, and proof of concept for weight loss 2.
That matters because 8 weeks of early biomarker data cannot prove the same benefits as months or years of physical activity. Exercise affects the heart, blood vessels, brain, muscle, bone, mood, and balance in ways no drug has fully replaced.
How ATX-304 differs from peptides and GLP-1 medications
ATX-304 is not in the same category as longevity peptides like GHK-Cu, NAD+, or sermorelin, and it is not a GLP-1 medication. Semaglutide is a GLP-1 receptor agonist, while tirzepatide is a dual GIP and GLP-1 receptor agonist 4, 5.
Can you buy ATX-304 for personal use?
ATX-304 is not an FDA-approved medication for personal use. If you see it sold online as a research chemical, that does not make it safe, legal, or appropriate to use in your body.
Why clinical-stage drugs are different from prescribed medications
Clinical-stage drugs are studied under research protocols with defined eligibility rules, monitoring, adverse-event reporting, and oversight. FDA-approved prescription medications have been reviewed for specific labeled uses, dosing, contraindications, warnings, and manufacturing standards 6.
Research-use-only sellers and why that does not mean human use is safe
Research-use-only products are typically sold for laboratory work, not patient care. They may not meet standards for sterility, identity, stability, impurities, or human dosing, and they do not come with clinician monitoring.
Why a CAS number or certificate of analysis is not enough for patient safety
A CAS number identifies a chemical substance. A certificate of analysis may describe one batch test. Neither one proves that an online ATX-304 product is safe for human use, free of harmful impurities, properly stored, clinically studied in that form, or appropriate for your medical history.
What to ask a licensed clinician before using any metabolic drug
- Is this product approved for human use, or is it research-use-only?
- What human data support the goal I care about?
- What side effects, drug interactions, or lab changes should be monitored?
- How would this interact with diabetes, liver disease, kidney disease, heart disease, or current medications?
- Is there a better-studied prescription option for my goal?
Does ATX-304 work for fat loss or weight loss?
ATX-304 has early signals related to fat metabolism, but it is not proven as a weight-loss treatment. The strongest published data are still animal data, and the human data are early, company-reported, and not enough to establish long-term outcomes.
What mouse data suggest about body fat, cholesterol, and fatty liver disease
In a mouse model of progressive fatty liver disease, ATX-304 reduced body fat mass, lowered blood cholesterol, reduced liver steatosis, and mitigated liver fibrosis development 3. The same study linked these changes with increased fatty acid oxidation, reduced lipid synthesis, and changes in cholesterol and lipid transport 3.
This is animal evidence. It does not prove that ATX-304 causes fat loss, weight loss, or fatty liver improvement in humans.
What early human data reported in adults with obesity and prediabetes
Cambrian Bio reported Phase 1b randomized, double-blind, placebo-controlled data in 23 adults with obesity and prediabetes. The company reported statistically significant changes in adiponectin, triglycerides, liver fat, visceral adipose tissue, and resting metabolic rate, while minimal weight loss was observed at that exposure level 2.
The company also reported that treatment-emergent adverse events were mostly mild and similar in frequency to placebo, with no adverse events related to core body temperature, flushing, or heart rate 2. That is reassuring as an early signal, but it does not prove long-term safety.
Why Phase 1b results do not prove long-term weight-loss benefit
A Phase 1b study is mainly designed to learn about safety, tolerability, and early biological activity. A small 23-person study cannot answer whether a drug leads to durable fat loss, muscle-sparing weight loss, fewer diabetes events, better liver outcomes, or fewer cardiovascular events.
What Phase 2 studies still need to show
Phase 2 studies need to test whether ATX-304 improves outcomes that patients can feel or measure over time: body weight, body composition, visceral adipose tissue, liver fat, glucose control, muscle function, adverse events, and medication interactions. Until those results are available, claims about ATX-304 for fat loss should stay cautious.
How might ATX-304 affect metabolism?
ATX-304 is designed to affect cellular energy balance through AMPK and mitochondria. The main proposed effects involve glucose uptake, fatty acid oxidation, mitochondrial respiration, and mitochondrial proton conductance.
AMPK and cellular energy balance
AMPK helps cells respond when energy demand changes. When AMPK is activated, cells tend to shift away from energy storage and toward energy use, including more glucose uptake and fat oxidation 3.
Glucose uptake, fatty acid oxidation, and mitochondrial respiration
Cambrian Bio describes ATX-304 as increasing both cellular glucose uptake and mitochondrial respiration, which may raise energetic supply and demand together 2. Its public pipeline page also describes increased mitochondrial proton conductance and fatty acid uptake as part of the AMPK network effect 1.
Why metabolic biomarkers are not the same as proven health outcomes
Biomarkers such as triglycerides, adiponectin, resting metabolic rate, liver fat, and visceral adipose tissue can be useful research signals. But biomarkers do not automatically mean fewer heart attacks, less type 2 diabetes, better liver health, or long-term weight loss.
How does ATX-304 compare with GLP-1 weight-loss treatments?
ATX-304 and GLP-1 medications work through different pathways and have very different access status. ATX-304 is investigational; semaglutide and tirzepatide are active ingredients with FDA-approved brand medications for chronic weight management, while compounded formulations are not FDA-approved.
| Option | Drug class or pathway | Evidence status | Access status | Key safety limits |
|---|---|---|---|---|
| ATX-304 / O-304 | Investigational AMPK network activator; oral small molecule | Mouse data and early company-reported Phase 1b human data | Not FDA-approved; Chia does not sell it | Long-term safety, dose strategy, interactions, and weight-loss outcomes are not established |
| Semaglutide, including Wegovy and Ozempic as brand examples; compounded semaglutide via 503A pharmacy is a separate compounded formulation | GLP-1 receptor agonist | Large trials of semaglutide as studied show weight-loss and cardiometabolic effects in selected populations | Brand products have FDA-approved indications; Chia can evaluate eligible patients for compounded semaglutide injection | Can cause gastrointestinal side effects; labeled warnings include pancreatitis, gallbladder disease, kidney injury, and thyroid C-cell tumor risk in rodents |
| Tirzepatide, including Zepbound and Mounjaro as brand examples; compounded tirzepatide via 503A pharmacy is a separate compounded formulation | Dual GIP and GLP-1 receptor agonist | Large trials of tirzepatide as studied show weight-loss and glycemic effects in selected populations | Brand products have FDA-approved indications; Chia can evaluate eligible patients for compounded tirzepatide tablets or injection | Can cause gastrointestinal side effects; labeled warnings include pancreatitis, gallbladder disease, kidney injury, and thyroid C-cell tumor risk in rodents |
ATX-304: investigational AMPK network activation
ATX-304 is aimed at the AMPK network, mitochondrial respiration, and metabolic demand 1. Because it is still investigational, access is through clinical research—not routine prescribing.
Semaglutide: GLP-1 receptor agonist pathway
Semaglutide is a GLP-1 receptor agonist. In the STEP 1 trial, semaglutide 2.4 mg once weekly as studied led to greater mean weight loss than placebo over 68 weeks in adults with overweight or obesity, alongside lifestyle intervention; individual results varied 7.
The FDA label for Wegovy lists gastrointestinal side effects such as nausea, diarrhea, vomiting, constipation, and abdominal pain, and warnings including pancreatitis, gallbladder disease, acute kidney injury, and a boxed warning about thyroid C-cell tumors in rodents 4. Compounded semaglutide formulations are not FDA-approved and do not have FDA-evaluated outcomes data.
Tirzepatide: dual GIP and GLP-1 receptor agonist pathway
Tirzepatide is a dual GIP and GLP-1 receptor agonist. In the SURMOUNT-1 trial, tirzepatide as studied led to greater mean weight reduction than placebo over 72 weeks in adults with obesity or overweight and at least one weight-related complication; individual results varied 8.
The FDA label for Zepbound lists common gastrointestinal side effects and warnings including pancreatitis, gallbladder disease, acute kidney injury, severe gastrointestinal disease, and a boxed warning about thyroid C-cell tumors in rodents 5. Compounded tirzepatide formulations are not FDA-approved and do not have FDA-evaluated outcomes data.
What is known, what is still unknown, and why access differs
The main difference is maturity of evidence. Semaglutide and tirzepatide have large human trial programs and FDA-labeled brand products for defined uses 4, 5. ATX-304 is still in clinical development, so buying it outside a trial means stepping outside normal prescription safeguards.
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Considering better-studied weight-loss care?
Chia does not offer ATX-304. We can evaluate eligible patients online for options we do offer, including compounded semaglutide injection, compounded tirzepatide tablets or injection, and related protocols. A prescription requires review by a licensed US provider and is never guaranteed. Compounded drugs are not FDA-approved.
What weight-loss treatments can Chia evaluate instead of ATX-304?
Chia does not offer ATX-304. For patients seeking weight-loss care, our providers can evaluate eligibility for compounded GLP-1 options and supportive protocols through a licensed, online medical review.
Chia does not offer ATX-304
ATX-304 is education-only in this article. We do not sell it, prescribe it, compound it, or recommend sourcing it from research chemical vendors.
Clinician-reviewed access to compounded semaglutide injection
Chia offers compounded semaglutide injection, with plans currently starting at $249/mo. Dosing is provider-guided and adjusted over time when clinically appropriate, including microdosing plans when a provider determines that path fits the patient.
Clinician-reviewed access to compounded tirzepatide tablets or injection
Chia offers compounded tirzepatide as tablets, with plans currently starting at $249/mo, and injection, with plans currently starting at $299/mo. Microdosing plans are available when clinically appropriate and provider-guided.
| Chia option | Forms Chia offers | Current starting price | Who may prefer it |
|---|---|---|---|
| Semaglutide | Injection | From $249/mo | Patients who prefer a once-weekly injectable GLP-1 plan after clinician review |
| Tirzepatide | Tablets or injection | Tablets from $249/mo; injection from $299/mo | Patients who want a provider-guided plan with a tablet or injectable form option |
| Weight + Energy | NAD+ injection plus choice of GLP-1 | From $309/mo | Eligible patients who want weight-loss care paired with NAD+ support |
| Weight + Muscle | Sermorelin injection plus choice of GLP-1 | From $329/mo | Eligible patients who want weight-loss care paired with sermorelin support |
Weight + Energy and Weight + Muscle protocols for eligible patients
Chia’s Weight + Energy protocol includes NAD+ injection plus a choice of GLP-1, with plans currently starting at $309/mo. Our Weight + Muscle protocol includes sermorelin injection plus a choice of GLP-1, with plans currently starting at $329/mo.
How the online questionnaire, provider review, prescription decision, and home shipping work
At Chia, care starts with a short online health questionnaire. A licensed US provider reviews your history, goals, medications, and safety factors, then prescribes only when clinically appropriate. If prescribed, medications are compounded in the US by state-licensed 503A compounding pharmacies and shipped to your door.
Patients can message their care team through the portal between visits. Dosing decisions, including any GLP-1 microdosing plan, must be individualized after clinical evaluation.
Who should avoid trying to source ATX-304 on their own?
Anyone should avoid using research-use-only ATX-304 for personal treatment. The risk is higher for people with medical conditions, complex medication lists, pregnancy-related concerns, or weight-loss goals that need monitoring.
People with diabetes, liver disease, heart disease, or complex medication lists
People with diabetes, liver disease, heart disease, kidney disease, or multiple medications should not self-experiment with metabolic drugs. AMPK-related pathways overlap with glucose handling, lipid metabolism, mitochondrial function, and energy balance, which can matter for safety and monitoring 3.
People who are pregnant, trying to conceive, or breastfeeding
Pregnancy, trying to conceive, and breastfeeding require extra caution with metabolic medications. For approved weight-loss GLP-1 drugs, FDA labels include pregnancy-related warnings and advise stopping when pregnancy is recognized 4, 5. ATX-304 does not have an FDA label that defines safe use in these situations.
People seeking fat loss without medical evaluation
Weight-loss medications are not just appetite or metabolism tools. A clinician should look at blood pressure, heart risk, gallbladder history, pancreatitis history, eating-disorder history, medications, pregnancy plans, and lab needs before treatment is considered 9.
Why eligibility and monitoring matter for metabolic medications
Monitoring helps catch side effects, adjust treatment, and decide whether a plan is helping. The American Diabetes Association notes that obesity treatment should be individualized and may include lifestyle therapy, medication, metabolic surgery, and ongoing review depending on the patient 9.
What is the safer next step if you were searching for ATX-304?
The safer next step is not to buy ATX-304 online. It is to talk with a licensed clinician about your goal—fat loss, prediabetes, liver fat, energy, or cardiometabolic risk—and review options with human safety data.
If your goal is weight loss, Chia can evaluate whether a compounded GLP-1 plan is clinically appropriate. If your goal is research curiosity, the honest answer is that ATX-304 remains a compound to watch—not a do-it-yourself treatment.
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Start with a licensed medical review
If you were searching for ATX-304 because you want help with weight or metabolic health, Chia can review your eligibility for treatments we do offer. Start with the online visit at /quiz. A prescription is never guaranteed, and compounded medications are not FDA-approved.
ATX-304 is not an FDA-approved prescription medication for personal use. If you see it sold online as a research chemical, that does not mean it is safe or appropriate for human use. Chia does not sell ATX-304.
No. ATX-304, also called O-304, is described in available sources as an oral small molecule AMPK activator. It is not a peptide.
No. ATX-304 is investigational and is not FDA-approved for weight loss, fat loss, prediabetes, type 2 diabetes, MASLD, MASH, or any other patient use.
No. Chia does not offer, sell, prescribe, or compound ATX-304. Chia can evaluate eligible patients for treatments listed in its current catalog, including compounded semaglutide injection and compounded tirzepatide tablets or injection.
It is too early to say. Mouse data and early company-reported human data show metabolic signals, but they do not establish long-term safety or proven fat-loss outcomes for general patient use.
Some online sellers may list a CAS number for ATX-304 or O-304, but a CAS number only identifies a chemical substance. It does not prove that a product is safe, sterile, correctly made, legal for human use, or appropriate for you.
Yes, ATX-304 is also commonly referred to as O-304 in research discussions. Some online content may also mention OS-01, but naming can vary across non-clinical sources.
They are not the same type of drug. Semaglutide is a GLP-1 receptor agonist, and tirzepatide is a dual GIP and GLP-1 receptor agonist. They are better-studied weight-loss pathways than ATX-304, but whether either is right for you requires a licensed medical evaluation. Compounded formulations are not FDA-approved.
References
- 1.Cambrian Bio. ATX-304. Cambrian Bio pipeline page, 2026.
- 2.Cambrian Bio. Cambrian Bio Presents Positive Human Translational Data for ATX-304, the First AMPK Network Activator, at the American Diabetes Association’s 86th Scientific Sessions, 2026.
- 3.AMPK activator ATX-304 reduces oxidative stress and improves fatty liver disease in a preclinical mouse model. Journal of Clinical Investigation Insight, 2025.
- 4.U.S. Food and Drug Administration. Wegovy (semaglutide) prescribing information, 2024.
- 5.U.S. Food and Drug Administration. Zepbound (tirzepatide) prescribing information, 2025.
- 6.U.S. Food and Drug Administration. Development and Approval Process: Drugs, 2024.
- 7.Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine, 2021.
- 8.Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine, 2022.
- 9.American Diabetes Association Professional Practice Committee. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Care in Diabetes—2026. Diabetes Care, 2026.
About this article
Chia Health Editorial Team — Evidence-reviewed health education
This article is for educational purposes only and is not a substitute for individualized medical advice. Talk to a licensed clinician before starting, stopping, or changing any prescription.
AI tools may assist with research and drafting. Chia's editorial team reviews source use, clarity, treatment information, and safety framing before publication. A clinician is named only after explicit sign-off. Read our editorial standards.
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