Cardarine (GW-501516)
Also known as: GW-501516, GW1516, GSK-516, Endurobol
Overview
Cardarine (GW-501516) is a PPARδ (peroxisome proliferator-activated receptor delta) agonist, not a SARM in the strict sense, but it is commonly grouped with SARMs in research and performance communities. Originally co-developed by GlaxoSmithKline and Ligand Pharmaceuticals, Cardarine's clinical development was terminated in 2007 when toxicology studies revealed dose-dependent carcinogenic potential in multiple organ tissues in rodent models after 2-year exposure. Despite this, GW-501516 continues to be researched and used due to its dramatic effects on fat oxidation and endurance capacity.
Mechanism of Action
GW-501516 binds to and activates PPARδ receptors, transcription factors that regulate genes involved in fatty acid metabolism, mitochondrial biogenesis, and energy expenditure. Activation shifts muscle fuel utilization from glucose to fatty acids, increasing fat oxidation and improving mitochondrial function. PPARδ activation also upregulates GLUT4 expression (improving insulin sensitivity), stimulates slow-twitch oxidative muscle fiber development, and activates AMPK signaling — producing effects similar to endurance exercise training without the physical effort.
Potential Benefits
- Dramatic endurance improvement (60% increase in running distance in animal models)
- Enhanced fat oxidation and weight loss without catabolism
- Improved insulin sensitivity and glucose metabolism
- Mitochondrial biogenesis in skeletal muscle
- Shift toward oxidative muscle fiber type
- Potential HDL cholesterol improvement
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Typical Range | 10-20 mg/day |
| Beginner | 10 mg/day |
| Intermediate | 15-20 mg/day |
| Advanced | 20 mg/day maximum; higher doses increase carcinogenicity concern |
| Cycle Duration | 4-8 weeks maximum (shorter cycles recommended given carcinogenicity data) |
| Cycle Off | 8-12 weeks minimum |
IMPORTANT: Carcinogenic potential in rodent models led to clinical discontinuation. Research use only. Shorter cycles are advisable given the carcinogenicity findings in chronic rodent exposures. Not recommended for long-term use.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Oral High
Good oral bioavailability; half-life ~16-24 hours; once-daily dosing; no injection required
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Cardarine (GW-501516):
Endurance and Fat Loss Stack
Maximal fat oxidation with muscle preservation during a cut
Cardarine dramatically improves fat burning and endurance; Ostarine maintains lean mass and provides some joint protection during caloric deficit.
Metabolic Optimization Stack
PPAR-δ and AMPK-driven metabolic enhancement
Both activate overlapping pathways for mitochondrial biogenesis and fat oxidation; complementary mechanisms for metabolic enhancement.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Typical Vial Size | N/A — oral capsules or liquid suspension (10-20mg/ml) |
|---|---|
| BAC Water | N/A — oral formulation |
| Storage | Store at room temperature 15-25°C; protect from light and moisture |
| Shelf Life | 24-36 months sealed |
Need exact syringe measurements?
Amino Acid Sequence
N/A — non-peptide small molecule PPARδ agonist
Side Effects & Safety
- CRITICAL: Carcinogenicity shown in rodent studies after chronic exposure
- Cancer risk in humans not established but theoretical based on rodent data
- Potential hepatotoxicity at high doses
- No androgenic suppression (not AR-mediated)
- GI discomfort at high doses
- The carcinogenicity concern led to discontinuation of clinical development
Synergistic Compounds
The following compounds have been studied alongside Cardarine (GW-501516) for potential complementary or synergistic effects:
Learn More
References & Further Reading
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