Cardarine vs SR9009 (Stenabolic): The Risk and Anti-Doping Truth, Not a Gains Guide (2026)
If you are comparing Cardarine and SR9009 to pick a "better" endurance compound, the honest answer is that there is no safe winner here: both are WADA-banned research chemicals with zero human trials, and the most important facts are about risk, not results. Cardarine carries a documented multi-organ cancer signal from rat studies. SR9009 barely absorbs when swallowed, so the oral product most people buy is probably doing very little. This page is built to foreground those two facts, not to crown a performance enhancer.
Most "Cardarine vs SR9009" pages put the mechanism and the gains up top and bury the carcinogenicity and the anti-doping status in a side-effects paragraph near the bottom. We invert that on purpose. The decision-shaping information is the safety and legality, so it leads. For where these two sit among the wider field of aerobic compounds, see our hub on the best peptides for endurance and aerobic performance; for the deeper science on either molecule we link up to its dedicated guide, and for what real people do we add first-party community data no competitor has.
Head-to-head
Edge: Cardarine — by a slim margin
Neither Cardarine (GW-501516) nor SR9009 (Stenabolic) is a peptide, a SARM, or an approved drug: both are WADA-banned research chemicals sold 'not for human consumption,' with zero human efficacy or safety trials. The honest comparison is about risk and status, not 'which is better for gains.' Cardarine is a PPARd agonist banned under WADA class S4.4.1 whose development GSK halted in 2007 after dose-dependent multi-organ cancers in rats; SR9009 is a REV-ERB agonist with near-zero oral bioavailability, so oral 'SR9009' products are likely inactive as sold. The moat below is what the ProtocolPlus community actually does: among users tracking these two, the adoption split, the ~35% who co-track both for endurance, and a near-even switch flow. The fit-score radar is a secondary editorial 'why,' not an endorsement; Cardarine's safety dimension is deliberately scored lowest (1/5) because of the rat-carcinogenicity signal.
Overall fit score
By dimension
Side by side
| Cardarine | Stenabolic | |
|---|---|---|
| Class | Non-peptide research chemical; PPARd agonist (not a SARM) | Non-peptide research chemical; REV-ERB agonist (not a SARM) |
| Primary target | PPARd (peroxisome proliferator-activated receptor delta) | REV-ERBa/b (circadian / mitochondrial nuclear receptors) |
| FDA / approval status | Not approved; development halted by GSK in 2007; sold 'not for human consumption' | Not approved; never entered human development; sold 'not for human consumption' |
| WADA status | Prohibited at all times, class S4.4.1 (PPARd agonist), since 2009 | Prohibited at all times (hormone & metabolic modulator / gene-expression class) |
| Key safety flag | Dose-dependent multi-organ cancers in 2-year rat study (GSK/ToxSci); reason development stopped | Near-zero oral bioavailability (~2.2% orally in rodents); animal-only data, no chronic safety data |
| Human evidence | None. Endurance 'exercise mimetic' effect shown in mice only (Narkar et al., Cell 2008) | None. Endurance/metabolic effects shown in mice only (Solt et al., Nature 2012) |
| Route as sold | Oral (liquid/capsule); orally active in animals | Oral (liquid/capsule), but oral route is largely ineffective; was injected in studies |
| Community adoption (illustrative app data) | 544 users (69%) of the pair; the more-tracked of the two | 240 users (31%) of the pair; ~35% of pair users co-track both |
Educational. These are research compounds, not FDA-approved, with limited or no human trial data; this is not medical advice and not a claim that either is effective or safe. Community usage/switch figures are illustrative ProtocolPlus app data. Verify everything with a clinician.
Key Takeaways
- Neither is established-safe, and there is no "winner" for use. Both are research chemicals, never approved for humans, with no human efficacy or safety trials. This is harm-reduction information, not a recommendation.
- Both are banned in sport at all times. Cardarine is on the WADA Prohibited List under class S4.4.1 (hormone and metabolic modulators; a PPARd agonist), prohibited since 2009. SR9009 is also WADA-prohibited. Both are detectable in anti-doping tests.
- Cardarine's defining red flag is cancer. A two-year GSK rat study (5 and 40 mg/kg/day) produced dose-dependent tumors across multiple organs (including liver, stomach, skin, and bladder). GSK halted development in 2007 for this reason. This is why its safety score on this page is the lowest possible (1 of 5).
- SR9009's defining problem is that it barely works orally. Its oral bioavailability is near zero (about 2.2% absorbed in rodents), so the oral capsules and liquids sold as "SR9009" are likely inactive as taken. Its endurance data is from injected mice, not people.
- All human-relevant effects are mouse data. Cardarine's endurance "exercise mimetic" effect (Narkar et al., Cell 2008) and SR9009's metabolic effect (Solt et al., Nature 2012) were shown in rodents only.
- What our community does (ProtocolPlus app data): among users tracking these two, the split is about 69% Cardarine, 31% SR9009, roughly 35% co-track both for endurance stacks, and the net switch flow is close to even (a slight net toward SR9009). A usage signal, not proof either is better or safer.
[!WARNING] Banned in sport. Not for human use. Rodent carcinogenicity. Cardarine and SR9009 are sold as "research chemicals not for human consumption." Both are on the WADA Prohibited List and will trigger an anti-doping violation. Cardarine showed dose-dependent, multi-organ cancers in rats, which ended its development. Nothing on this page should be read as a green light to take either compound.
How risky is each one, and what is its anti-doping status?
The one-sentence answer: both are WADA-banned at all times and neither has any human safety data, but the specific red flags differ. Cardarine's is a documented cancer signal; SR9009's is a near-total lack of testing combined with a delivery problem. Here is the risk-and-status picture before any talk of effects, because for most readers this is the part that actually decides the question.
| Risk / status dimension | Cardarine (GW-501516) | SR9009 (Stenabolic) |
|---|---|---|
| Drug class | PPARd agonist (not a SARM) | REV-ERB agonist (not a SARM) |
| FDA approval | None; GSK halted development in 2007 | None; never entered human development |
| Sold as | "Research chemical, not for human consumption" | "Research chemical, not for human consumption" |
| WADA status | Prohibited at all times, class S4.4.1, since 2009 | Prohibited at all times (metabolic modulator class) |
| Defining safety flag | Dose-dependent multi-organ cancers in 2-year rat study | Animal-only data; near-zero oral bioavailability |
| Human trials | None | None |
| Detectable in testing | Yes | Yes |
The table is the headline. Cardarine is the more-studied of the two, and what that extra study found is alarming: a clear, dose-related carcinogenicity signal. SR9009 has no comparable cancer finding, but that reflects far less testing rather than a clean bill of health, and it has a practical flaw that makes the oral product questionable in the first place. Neither status improves with time, and neither is reversible if something goes wrong.
Cardarine and cancer: the finding that ended its development
This is the single most important fact on the page, so it does not get buried. GSK ran a standard two-year carcinogenicity program in rats at 5 and 40 mg/kg/day. The animals developed dose-dependent tumors across multiple organ systems, and GSK terminated the program in 2007 as a result. WADA cited that long-term animal carcinogenicity when it added GW501516 to the Prohibited List and later issued an unusual public warning to athletes that the compound is not safe. There is no human data showing that a "low bodybuilding dose" avoids this risk, because the human safety studies that would answer that question were never done and never will be. Anyone presenting Cardarine as "clean because it is not a steroid" is leaving out the reason it was abandoned.
It is worth understanding why the finding is so hard to wave away. The tumors were not a freak result at one extreme dose; they appeared across a range and got worse as the dose rose, which is the classic pattern of a true carcinogenic effect rather than a chance cluster. They also showed up in several unrelated tissues at once, not a single organ, which points to the drug's core mechanism rather than to a quirk of one cell type. PPARd sits at the center of cell metabolism and proliferation, and chronically forcing it on appears to be the kind of thing that can drive abnormal growth over time. The common counter-argument, that the study used doses far above what a person would take, is weaker than it sounds: the standard two-year rodent assay is the deliberate, regulator-accepted way to surface exactly this hazard, and a dose-response curve that is already climbing at the doses tested is not reassuring about lower, longer human exposure. No one has data on what years of human use would do, which is the entire problem.
SR9009: the oral-bioavailability problem most sellers skip
SR9009's headline problem is mundane but decisive: it is barely absorbed when swallowed. In the rodent pharmacokinetics from the Burris lab, oral bioavailability sits near 2.2%, and the original animal experiments that produced its endurance and metabolic effects used frequent injection, not capsules. The lab that discovered it moved on to successor molecules partly for this reason. Practically, that means most oral "SR9009" products are likely delivering very little active compound, so a buyer is exposing themselves to an unapproved, untested, banned substance for an effect that may not even be reaching their bloodstream. "Safer-looking" here is partly an artifact of a compound that may not be doing much orally.
Two further wrinkles compound the delivery problem. First, SR9009 has a very short half-life, on the order of a few hours, which is why the animal protocols dosed it frequently throughout the day rather than once. A single daily capsule does not reproduce that exposure pattern even setting absorption aside. Second, the sublingual and "liposomal" formats marketed to work around the absorption problem are not validated; there is no published human pharmacokinetic data showing they deliver a meaningful, sustained blood level, so they are best treated as marketing claims rather than solved engineering. The net effect is a compound whose real-world consumer version sits in an awkward place: if it is inactive, you took a banned research chemical for nothing; if a workaround format does deliver it, you are now getting an untested dose of an untested compound. Neither outcome is good, and neither is something a label on a grey-market bottle can tell you.
What does the ProtocolPlus community actually do between the two?
This is the part no study and no vendor page gives you: among users who log these two, how do people actually use them? We are explicit that this is a usage signal, not an efficacy or safety verdict, and that everything below describes behavior, not a recommendation. The short version is that Cardarine is the more-tracked of the pair, a large minority run both together as an endurance stack, and the switch traffic between them is close to even, unlike the lopsided flows seen with approved drugs.
Three numbers carry the story, all from ProtocolPlus app data among the roughly 784 users tracking one of these two compounds:
- Adoption split: about 69% Cardarine (544 users), 31% SR9009 (240 users). Cardarine is clearly the more-tracked of the pair, likely because it is orally active and has the longer informal use history, despite carrying the heavier safety flag.
- Co-tracking: about 35% (roughly 274 users) log both. This is the highest co-tracking share among our research-chemical pairs, and it reflects the well-known endurance "stack" where people run the two together rather than choosing one.
- Net switch is close to even, a slight lean to SR9009. About 18% of SR9009 users (roughly 43) later moved to or added Cardarine, and about 16% of Cardarine users (roughly 87) moved the other way; the small net of about 44 users tilts toward SR9009, a ratio near 1-to-1. There is no clear migration "winner" the way there is with approved drugs.
A note on honesty about gaps: unlike our approved-drug comparisons, this pair has no side-effect comparison data and no per-dose cost data in our system. Neither research chemical has a structured tolerability profile in the app, and pricing is inconsistent across grey-market sellers, so we do not show or estimate those numbers here rather than fabricate them. The adoption, co-tracking, and switch direction are the parts we can stand behind.
The near-even switch flow is itself the story. With approved drugs you usually see a lopsided migration toward the stronger molecule. Here you do not, and the reason is that the dominant pattern is co-use, not replacement: a large share of people run both together as an endurance stack, so "switching" often just means adding the other one. That is also why neither compound's adoption tells you it is safer. Popularity and stacking habits are not evidence.
What each compound actually does (in animals, not people)
The one-sentence answer: in rodents, Cardarine pushed fat oxidation and endurance by acting as an "exercise mimetic," while SR9009 shifted metabolism and endurance by targeting the circadian REV-ERB pathway, but neither effect has ever been demonstrated in a human trial. The mechanisms are genuinely different, which is why some people stack them, but the evidence floor for both is mouse data.
Cardarine activates PPARd, a nuclear receptor that, when switched on, upregulates genes for fatty-acid oxidation and mitochondrial efficiency in muscle. In the foundational mouse work (Narkar et al., Cell 2008), PPARd activation combined with exercise dramatically increased running endurance, which is the source of the "exercise in a pill" framing the supplement market borrowed. It is orally active in animals, which is part of why it became the more-tracked of the two.
SR9009 targets REV-ERBa and REV-ERBb, nuclear receptors tied to the circadian clock and to mitochondrial biogenesis. In the original mouse study (Solt et al., Nature 2012), synthetic REV-ERB agonism increased metabolic rate and endurance and altered lipid handling. The catch, again, is delivery: those effects came from injected compound, and the near-zero oral bioavailability means the consumer oral format is a poor stand-in for the studied route. For the full pharmacology of each, see the Cardarine guide and the Stenabolic guide. This page stays a decision hub and does not re-explain either molecule end to end.
Is either one a SARM? Clearing up the biggest misconception
The one-sentence answer: no, neither Cardarine nor SR9009 is a SARM, and neither is a peptide. They get lumped in with SARMs by sellers and forums, but they act on completely different receptors and do not touch the androgen receptor at all.
A SARM (selective androgen receptor modulator) works on the androgen receptor, the same target as testosterone, which is why SARMs raise questions about testosterone suppression and post-cycle therapy. Cardarine and SR9009 do not bind the androgen receptor. Cardarine is a PPARd agonist and SR9009 is a REV-ERB agonist, both nuclear-receptor compounds aimed at metabolism and endurance rather than muscle-building via androgens. The practical upshot is that the standard SARM concerns about hormonal suppression are not the central issue here. The central issues are the carcinogenicity signal (Cardarine) and the testing-and-delivery problems (both). Calling them SARMs is not just imprecise; it imports the wrong risk model.
What about cholesterol and cardiovascular effects?
The one-sentence answer: both compounds shift lipid metabolism in animal models, and that is a double-edged thing, an unproven possible benefit on paper against unknown long-term cardiovascular risk in humans that no trial has ever measured. Treat any "good for your cholesterol" claim as animal data, not a human outcome.
In rodents, PPARd activation (Cardarine) and REV-ERB agonism (SR9009) both nudge lipid handling, and some preclinical work reported lower triglycerides and changes in cholesterol fractions. That is the basis for the marketing line that these compounds "improve your lipid panel." The honest reading is narrower. A surrogate marker moving in a study animal is not the same as a person living longer or having fewer heart attacks, and the history of metabolism drugs is full of compounds that improved a lab number while doing nothing good, or something bad, for actual cardiovascular outcomes. For Cardarine specifically, the same chronic PPARd activation that shifts lipids is the mechanism implicated in the carcinogenicity, so you cannot cleanly separate the hoped-for benefit from the documented hazard. For SR9009, the poor oral delivery means most users may not be getting enough compound to move anything at all. Anyone using either to "fix" a cholesterol problem would be better served by interventions that actually have human outcome data, which is a conversation for a clinician, not a forum.
The editorial scorecard (and why we score Cardarine's safety lowest)
The fit-score radar below rates each compound 1 to 5 on six dimensions. We want to be explicit about one number: Cardarine's safety is scored 1 of 5, the lowest on the scale, because of the rat carcinogenicity finding. That is a deliberate editorial choice, not an artifact. SR9009 scores a 2 on safety, edging Cardarine only because it lacks a comparable cancer signal, not because it is proven safe. With equal weighting the two are close (a slim fit-score edge to Cardarine on evidence and the rodent endurance effect), but read this radar as context, never as a recommendation. The community usage data above, and the safety facts, are the real signal.
If someone is set on using one anyway: harm-reduction framing
We will not pretend people never use these, so this section is honest about how the choice tends to break, while restating that neither is established-safe and both are banned. The point is informed risk, not a protocol.
People lean Cardarine when:
- They want the rodent-shown endurance effect and care that it is actually orally active, unlike SR9009.
- They accept the heaviest red flag on this page: the multi-organ rat carcinogenicity that ended its development.
- They are not subject to drug testing, since it is a WADA S4.4.1 banned substance that testing can detect.
People lean SR9009 when:
- They are uneasy about Cardarine's specific cancer signal and prefer a compound without one on record, while understanding "no signal" means "barely tested," not "safe."
- They accept that the oral product they buy may be largely inactive given near-zero oral bioavailability.
- They are willing to dose frequently because of its very short half-life, the way the animal studies did.
Neither column is advice. Both compounds are banned in sport, unapproved for humans, and untested for human safety. The most defensible choice for performance and health is a clinician-guided plan and, where relevant, evidence-based options that are actually legal and studied.
The honest verdict
There is no "which should I take" winner here, and presenting one would be dishonest. Cardarine is the more-used and orally-active of the two, but it carries a documented, development-ending cancer signal from rat studies and a WADA S4.4.1 ban. SR9009 lacks that specific cancer finding but is so poorly absorbed orally that the product most people buy may do little, and it is equally banned and equally untested in humans. Both are research chemicals, not medicines. The community runs them, often together, for a rodent-demonstrated endurance effect that has never been confirmed in a person.
To make the takeaway concrete:
- If your goal is safety: neither is established-safe; the only defensible move is to avoid both and talk to a clinician.
- If you compete in tested sport: both are prohibited at all times and detectable; using either risks a sanction.
- If you are weighing the specific risks: Cardarine's is a multi-organ cancer signal in rats; SR9009's is a near-total lack of testing plus an oral product that may be inactive.
- If you are chasing the rodent endurance effect: understand it has never been shown in humans, and the "exercise mimetic" framing is marketing built on mouse data.
For the molecule-level science, see the Cardarine guide and the Stenabolic guide. To see where these and other compounds fall when people pursue endurance and conditioning goals, see best peptides for endurance and best peptides for cycling.
Frequently Asked Questions
Sources
- World Anti-Doping Agency. "The Prohibited List" (2025): GW1516 (GW501516, Cardarine) listed under S4.4.1, PPARd agonists; prohibited at all times. Retrieved 2026-06-18. https://www.wada-ama.org/en/prohibited-list
- U.S. Anti-Doping Agency (USADA). "What Should Athletes Know About GW1516?": GW1516 prohibited under S4.4.1; safety warning to athletes. Retrieved 2026-06-18. https://www.usada.org/spirit-of-sport/what-should-athletes-know-gw1516/
- Narkar VA, Downes M, Yu RT, et al. "AMPK and PPARd Agonists Are Exercise Mimetics." Cell, 2008;134(3):405-415. Endurance effect of PPARd activation in mice. Retrieved 2026-06-18. https://pubmed.ncbi.nlm.nih.gov/18674809/
- Mitchell JA, Bishop-Bailey D. "PPARb/d a potential target in pulmonary hypertension blighted by cancer risk." Pulmonary Circulation, 2019: summarizes GSK two-year rat carcinogenicity and the 2007 halt of GW501516 development. Retrieved 2026-06-18. https://onlinelibrary.wiley.com/doi/full/10.1177/2045894018812053
- Solt LA, Wang Y, Banerjee S, et al. "Regulation of Circadian Behaviour and Metabolism by Synthetic REV-ERB Agonists." Nature, 2012;485(7396):62-68. SR9009 endurance and metabolic effects in mice. Retrieved 2026-06-18. https://pubmed.ncbi.nlm.nih.gov/22460951/
- GW501516. Wikipedia (citing GSK toxicology and WADA listing): two-year Han Wistar rat study at 5 and 40 mg/kg/day, multi-organ tumors, development terminated 2007. Retrieved 2026-06-18. https://en.wikipedia.org/wiki/GW501516
- SR9009. Wikipedia (citing Solt et al. and follow-up pharmacology): near-zero oral bioavailability (~2.2%), short half-life, successor compounds developed. Retrieved 2026-06-18. https://en.wikipedia.org/wiki/SR9009
- ProtocolPlus. "Community head-to-head data: Cardarine vs SR9009" (head-to-head/cardarine__stenabolic.json). First-party app data, 2026. n ~ 784 users tracking one of the two. Usage and switching signal only; no side-effect or cost comparison available for this pair; not a clinical efficacy or safety verdict.