Cardarine (GW-501516) vs SR-9009 (Stenabolic)

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

✅ Stacking Partners — These compounds are commonly used together and may have synergistic effects.
Cardarine (GW-501516)SR-9009 (Stenabolic)
CategorySARMsSARMs
Standard DoseResearch indicates 10-20 mg daily orally for 8-12 weeks. Clinical trials (metabolic syndrome) used 2.5-10 mg/day.Research indicates 20-30 mg daily orally, split into 3-4 doses due to very short half-life (~4 hours). Some users prefer sublingual administration for improved bioavailability.
TimingOnce daily, 1-2 hours before exercise for acute endurance benefit. Half-life approximately 16-24 hours. Consistent daily dosing.Split into 3-4 doses throughout the day due to ~4-hour half-life. Example: 7am, 11am, 3pm, 7pm. Avoid late-night dosing as REV-ERB modulation may affect circadian rhythm and sleep.
Cycle Duration8-12 week cycles. No HPG suppression, so PCT is not required. However, long-term safety is unknown and cycling is prudent.8-12 week cycles. No HPG suppression. Cycling recommended due to limited long-term data.
Evidence Levelanimal_plus_anecdotalanimal_plus_anecdotal

Mechanism

Cardarine is a selective peroxisome proliferator-activated receptor delta (PPARd) agonist, not a SARM (it does not bind the androgen receptor). PPARd activation in skeletal muscle upregulates genes for fatty acid oxidation (CPT1B, PDK4, ACOX1), shifting fuel substrate from glycolysis toward beta-oxidation, effectively increasing endurance capacity and fat utilization. It increases oxidative type I (slow-twitch) muscle fiber proportion, enhances mitochondrial biogenesis via PGC-1a coactivation, reduces circulating triglycerides and LDL, and increases HDL cholesterol. PPARd activation also reduces macrophage-mediated inflammation through NF-kB suppression.

Standard Dosing

Research indicates 10-20 mg daily orally for 8-12 weeks. Clinical trials (metabolic syndrome) used 2.5-10 mg/day.

Timing

Once daily, 1-2 hours before exercise for acute endurance benefit. Half-life approximately 16-24 hours. Consistent daily dosing.

Cycle Duration

8-12 week cycles. No HPG suppression, so PCT is not required. However, long-term safety is unknown and cycling is prudent.

Side Effects

  • CANCER RISK: Accelerated tumor development in multiple organs observed in 2-year rodent study at all doses tested
  • Headache
  • Nausea
  • Diarrhea
  • Potential liver effects at high doses

Contraindications

  • Active or history of cancer (CRITICAL — see notes on carcinogenicity)
  • Pregnancy and breastfeeding
  • Individuals under 21
  • Liver disease

Best Stacking Partners

Ostarine (popular body recomposition stack — cardarine adds fat loss/endurance without hormonal suppression)SR-9009 (complementary metabolic mechanisms)MK-677 (recovery and appetite counter to cardarine's potential appetite reduction)

Mechanism

SR-9009 is a synthetic agonist of REV-ERBa and REV-ERBb, nuclear receptors that form the repressive limb of the circadian clock and regulate metabolic gene expression. REV-ERB activation represses BMAL1/CLOCK transcription, modulating circadian rhythm. In skeletal muscle, SR-9009 increases mitochondrial count and oxidative capacity by upregulating mitochondrial biogenesis genes. It enhances fatty acid and glucose oxidation, increases exercise endurance, and reduces lipogenesis in the liver. SR-9009 also reduces inflammatory gene expression via NF-kB pathway suppression. Recent research has identified significant REV-ERB-independent effects, suggesting the mechanism is more complex than initially characterized.

Standard Dosing

Research indicates 20-30 mg daily orally, split into 3-4 doses due to very short half-life (~4 hours). Some users prefer sublingual administration for improved bioavailability.

Timing

Split into 3-4 doses throughout the day due to ~4-hour half-life. Example: 7am, 11am, 3pm, 7pm. Avoid late-night dosing as REV-ERB modulation may affect circadian rhythm and sleep.

Cycle Duration

8-12 week cycles. No HPG suppression. Cycling recommended due to limited long-term data.

Side Effects

  • Insomnia or sleep disruption (circadian clock modulation)
  • Anxiety or wakefulness
  • Headache
  • Nausea
  • Potential circadian rhythm disruption with chronic use

Contraindications

  • Circadian rhythm disorders or shift work (may exacerbate disruption)
  • Pregnancy and breastfeeding
  • Individuals under 21
  • Severe insomnia

Best Stacking Partners

Cardarine GW-501516 (complementary fat oxidation pathways)Ostarine (body recomposition — SR-9009 adds metabolic enhancement without suppression)MK-677 (counters potential sleep disruption)

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