LGD-4033 (Ligandrol) vs SR-9009 (Stenabolic)

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

LGD-4033 (Ligandrol)SR-9009 (Stenabolic)
CategorySARMsSARMs
Standard DoseResearch indicates 5-10 mg daily orally for 8-12 weeks. Phase 1 data showed significant lean mass gains at 1 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, consistent timing. Half-life approximately 24-36 hours. No food timing requirements.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 maximum. PCT strongly recommended after all but the shortest/lowest-dose cycles.8-12 week cycles. No HPG suppression. Cycling recommended due to limited long-term data.
Evidence Levelmoderate_humananimal_plus_anecdotal

Mechanism

LGD-4033 is a potent nonsteroidal selective androgen receptor modulator with high AR binding affinity (Ki of approximately 1 nM). It demonstrates strong anabolic activity in muscle and bone with significantly reduced androgenic activity in prostate tissue, achieving an anabolic-to-androgenic ratio of approximately 10:1. LGD-4033 activates the AR with full agonist efficacy in muscle, upregulating the PI3K/Akt/mTOR pathway for protein synthesis and satellite cell recruitment. It produces dose-dependent suppression of SHBG, total testosterone, LH, and FSH, indicating significant HPG axis suppression even at low doses.

Standard Dosing

Research indicates 5-10 mg daily orally for 8-12 weeks. Phase 1 data showed significant lean mass gains at 1 mg/day.

Timing

Once daily, consistent timing. Half-life approximately 24-36 hours. No food timing requirements.

Cycle Duration

8-12 week cycles maximum. PCT strongly recommended after all but the shortest/lowest-dose cycles.

Side Effects

  • Significant testosterone suppression (dose-dependent; occurs even at 1 mg/day)
  • Suppressed SHBG, LH, and FSH
  • Elevated liver enzymes / hepatotoxicity (case reports of cholestatic liver injury)
  • HDL cholesterol suppression
  • Headache
  • Fatigue (late-cycle, from suppression)
  • Water retention

Contraindications

  • Androgen-sensitive cancers
  • Pre-existing liver disease or elevated liver enzymes
  • Pregnancy and breastfeeding
  • Individuals under 21
  • Athletes subject to WADA/anti-doping testing

Best Stacking Partners

Cardarine GW-501516 (endurance without additional suppression)MK-677 (GH secretagogue for recovery)NAC / TUDCA (liver protection)

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)

Not sure which is right for you?

Take our free assessment to get personalized recommendations based on your health goals, current stack, and biomarkers.

Get Your Free Protocol →or take the assessment →