Cardarine (GW-501516) — Dosing, Cycles, Half-Life & Side Effects
Cardarine (GW-501516) is a PPAR-δ agonist with a half-life of 16-24 hours. CRITICAL SAFETY WARNING: This PPAR-δ agonist was ABANDONED by GlaxoSmithKline in 2007 after animal studies showed it caused cancer to develop rapidly in multiple organs (liver, thyroid, tongue, stomach, testes) at doses of 3mg/kg/day - comparable to human dosing. WADA issued a public health warning in 2013 stating 'clinical approval has not, and will not be given for this substance.' Australia's TGA classified it as Schedule 10 (prohibited substance) in 2018. NOT RECOMMENDED FOR ANY USE due to documented carcinogenic risk. This page is educational harm-reduction reference compiled from peer-reviewed literature — not medical advice, not an endorsement, not a recommendation to use. Consult a licensed clinician before any decision.
Quick Facts
| Class | PPAR-δ Agonist |
|---|---|
| Half-life | 16-24 hours |
| Detection window | 90 days |
| Hepatotoxicity | Low |
| Suppression | 0/10 |
| Administration | oral |
Typical Dosing Ranges
Common dose range: NOT RECOMMENDED - Cancer risk at doses comparable to typical human use (3mg/kg/day in animals)
Cycle length: NOT RECOMMENDED
Time to steady state: ~5 days
Dose ranges are compiled from published pharmacokinetic studies and community-reported usage. Where a value is community-reported rather than clinically studied, this page and its structured data flag it. Lower end of any range is always the safer starting point.
Stacking Considerations
- No structural stacking blockers. Standard harm-reduction rules apply: minimize total androgen load, minimize oral exposure, and monitor bloodwork.
PCT Requirements
- Depot clearance estimate: ~5 days post-last-dose before SERM start (5 × apparent depot half-life of 24h).
- Never stack two SERMs. Extend a single SERM (tamoxifen OR enclomiphene/clomiphene) rather than combining.
- Use the cycle planner to generate a full protocol based on your complete stack, not this compound alone.
Side Effect Profile
- CAUSED CANCER IN MULTIPLE ORGANS in animal studies - development abandoned
- WADA PUBLIC HEALTH WARNING issued (2013)
- GlaxoSmithKline ABANDONED development due to carcinogenicity (2007)
- Schedule 10 prohibited substance in Australia (TGA 2018)
- No human safety studies - long-term trials deemed unethical
- Unknown long-term effects in humans
- Detection time up to 40 days
- Expensive
Known Interactions
No compound-specific interactions are catalogued in the current matrix. This does not mean no risk exists — it means there is no curated pairwise entry. Browse the full interaction matrix to cross-reference manually.
Monitoring (Bloodwork & Vitals)
- Comprehensive metabolic panel (baseline, mid-cycle, post-cycle)
- Lipid panel (total cholesterol, HDL, LDL, triglycerides)
- CBC (hemoglobin, hematocrit — watch for erythrocytosis)
- Sex-hormone panel (Total T, Free T, Estradiol sensitive, SHBG, LH, FSH)
- Blood pressure (weekly self-check; flag systolic >140 or diastolic >90)
Baseline bloodwork is recommended before any cycle. Discontinue if liver enzymes exceed 3× upper limit of normal or if hematocrit exceeds 54%.
Frequently Asked Questions
What is the half-life of Cardarine (GW-501516)?
Cardarine (GW-501516) has a half-life of approximately 16-24 hours. Clearance estimate: 24h × 5 = 120h = 5 days. This figure is used to determine injection frequency (for esters) and post-cycle clearance timing.
What is the typical dose range for Cardarine (GW-501516)?
Commonly reported ranges for Cardarine (GW-501516): NOT RECOMMENDED - Cancer risk at doses comparable to typical human use (3mg/kg/day in animals). Cycle length: NOT RECOMMENDED. These are compiled from published studies and community-reported usage — individual response varies and lower end is always preferred.
Does Cardarine (GW-501516) suppress natural testosterone?
Cardarine (GW-501516) causes minimal suppression of the HPTA axis (score 0/10). PCT may still be advisable depending on stack and duration.
Is Cardarine (GW-501516) liver toxic?
Hepatotoxicity rating: Low. Non-17αα compound — liver stress is lower but still warrants periodic monitoring during a cycle.
What is Cardarine (GW-501516) typically used for?
Cardarine (GW-501516) is commonly used for: NOT RECOMMENDED - documented carcinogenic risk in animal studies. Intended-use context does not imply safety — every use case carries the same underlying pharmacological risks.
Citations
- GSK Phase I/II data. 2007. GSK clinical development (terminated) — Half-life approximately 16-24 hours for GW-501516
- GSK 104-week rat studies. 2007. GSK preclinical (terminated) — Rapid multi-organ cancer in rats: liver, bladder, stomach, skin, thyroid, tongue, testes, ovaries, uterus. WADA issued public safety alert March 2013.
- Mitchell JL et al.. 2019. Pulmonary Circulation — Half-life ~16-24 hours in rodent PK; no human PK data — see PMC6475847. Rodent-only evidence.
- GlaxoSmithKline Phase II clinical trial termination (2007) - development abandoned due to carcinogenicity
- WADA Public Health Warning on GW501516 (2013): 'Clinical approval has not, and will not be given'
- Australian TGA Schedule 10 Classification (2018) - Prohibited substance
- Sahebkar A. New peroxisome proliferator-activated receptor agonists: potential treatments for atherogenic dyslipidemia and non-alcoholic fatty liver disease. Expert Opin Pharmacother. 2014;15(4):493-503. PMID: 24428677
Disclaimer
StackItSmart is an independent harm-reduction reference. The content above is compiled from peer-reviewed literature and is not medical advice, not an endorsement, and not a recommendation to use Cardarine (GW-501516). Performance-enhancing compounds carry legal, endocrine, cardiovascular, and hepatic risks. Consult a licensed clinician before any decision. StackItSmart does not provide sourcing, procurement, or dosing prescriptions.