SR9009 (Stenabolic) — Complete Research Guide

Introduction

SR9009, commonly referred to by its research designation “Stenabolic,” is a synthetic agonist of the Rev-Erb nuclear receptors (Rev-Erbα and Rev-Erbβ), developed by Professor Thomas Burris and colleagues at The Scripps Research Institute. Critically, SR9009 is not a selective androgen receptor modulator (SARM)—despite being commonly grouped with SARMs in research chemical contexts, its mechanism of action is entirely distinct, operating through the nuclear receptor family responsible for circadian clock regulation rather than the androgen receptor. This distinction is fundamental to interpreting its biological effects and designing appropriate research protocols.

Rev-Erb receptors function as constitutive transcriptional repressors that regulate core clock genes (Bmal1, Clock) and downstream targets governing metabolism, mitochondrial biogenesis, and inflammatory signaling. By activating these receptors, SR9009 influences a wide range of metabolic processes, making it a valuable tool compound for researchers studying circadian biology, lipid metabolism, glucose homeostasis, and exercise physiology.

Mechanism of Action

Rev-Erb Nuclear Receptor Agonism

Rev-Erbα and Rev-Erbβ are heme-binding nuclear receptors that repress transcription at RORE (Rev-Erb/ROR response element) promoter sequences by recruiting the NCoR/HDAC3 co-repressor complex. In their physiological context, Rev-Erb receptors are components of the molecular oscillator that generates circadian rhythms: they repress Bmal1 expression during the active phase of the circadian cycle, and their own expression is in turn regulated by the Clock:Bmal1 heterodimer, creating the transcription-translation feedback loop underlying ~24-hour periodicity.

SR9009 binds to the ligand-binding domain of Rev-Erbα and Rev-Erbβ, stabilizing the active (heme-bound-like) conformation and enhancing co-repressor recruitment. This pharmacological activation of Rev-Erb produces effects that mimic an extended or constitutively active repressor state on clock-controlled genes, compressing the circadian amplitude and shifting the balance of metabolic gene programs toward those active during periods of high Rev-Erb activity.

Downstream Metabolic Effects

Rev-Erb target genes include regulators of lipid metabolism (SREBP-1c, FASN), gluconeogenesis (PEPCK, G6Pase in liver), mitochondrial biogenesis (via Bmal1 → PGC-1α connections), and inflammatory pathways (NF-κB targets). SR9009 activation of Rev-Erb results in suppression of lipogenic and gluconeogenic gene programs, elevation of mitochondrial number and function in skeletal muscle, and attenuation of inflammatory gene expression in relevant tissues.

Research Evidence

The landmark study establishing SR9009’s metabolic effects in vivo was published by Woldt and colleagues (2013, Nature Medicine). This work demonstrated that SR9009 treatment in obese mice reduced fat mass, improved glucose tolerance, decreased total and LDL cholesterol, and enhanced exercise capacity. Skeletal muscle mitochondrial biogenesis was markedly increased, with higher mitochondrial content and oxidative enzyme activity in SR9009-treated animals. Critically, these effects occurred over a relatively short treatment window, suggesting that Rev-Erb agonism produces acute reprogramming of metabolic gene networks rather than requiring extended exposure.

Solt and colleagues (2012, Journal of Biological Chemistry) characterized SR9009’s pharmacological profile at Rev-Erbα and Rev-Erbβ, documenting its binding affinity, receptor selectivity, and ability to enhance NCoR recruitment. This study also noted that SR9009 exhibited poor oral bioavailability in rodent pharmacokinetic studies—estimated at approximately 2%—a finding with significant implications for in-vivo research design. The low oral bioavailability is attributed to rapid first-pass metabolism, and many published in-vivo studies have employed intraperitoneal (i.p.) injection rather than oral gavage to achieve adequate systemic exposure.

Subsequent research has investigated SR9009’s effects on inflammatory models, with studies documenting suppression of NF-κB-driven inflammatory cytokine production consistent with Rev-Erb’s known role in restraining inflammatory gene expression. Additional work has explored SR9009’s effects in circadian disruption models, atherosclerosis, and cancer cell proliferation, reflecting the broad regulatory reach of Rev-Erb target gene networks.

SR9009 vs. GW501516 (Cardarine)

SR9009 is frequently compared to GW501516 (Cardarine) in research contexts because both compounds affect endurance capacity and lipid metabolism in rodent studies. However, their mechanisms are fundamentally different and should not be conflated:

• Receptor Target: SR9009 acts on Rev-Erb nuclear receptors (circadian clock components); GW501516 acts on PPARδ (peroxisome proliferator-activated receptor delta).
• Primary Metabolic Effect: SR9009 increases mitochondrial biogenesis and represses lipogenesis/gluconeogenesis via Rev-Erb target gene suppression; GW501516 directly activates fatty acid oxidation gene programs via PPARδ response elements in muscle and adipose tissue.
• Circadian Component: SR9009 directly modulates circadian clock machinery; GW501516 does not have a primary clock-related mechanism.
• Oral Bioavailability: SR9009 has ~2% oral bioavailability in rodents (i.p. injection typically used in studies); GW501516 is orally bioavailable.
• Safety Profile: GW501516 was discontinued from clinical development due to rapidly accelerated cancer formation across multiple organ systems in long-term animal carcinogenicity studies—a critical safety signal. SR9009’s carcinogenicity profile has not been characterized to the same extent.

Research Observations and Limitations

Published pre-clinical studies consistently document reduced fat mass and improved metabolic parameters in obese rodent models, enhanced mitochondrial density and oxidative capacity in skeletal muscle, improved glucose and cholesterol profiles, and increased treadmill endurance in treated animals. SR9009 has also shown anti-inflammatory effects in relevant disease models.

The central limitation for translation of SR9009 findings is its poor oral bioavailability. Most of the compelling metabolic data comes from i.p. administration studies, and whether equivalent systemic exposure can be achieved via oral routes in humans remains uncharacterized. Long-term safety data are limited, human pharmacokinetic studies are not published, and SR9009 has no regulatory approval from the FDA or EMA as of the time of writing.

Sourcing SR9009 for Research

Researchers sourcing SR9009 for laboratory studies can find both solution and powder formats at chemyosarms.us. The SR9009 solution provides convenient dosing for in-vivo studies, while SR9009 powder offers flexibility for custom formulation and in-vitro work. All batches are accompanied by third-party certificates of analysis confirming purity and identity.

Researchers interested in comparing SR9009 with GW501516/Cardarine in parallel metabolic studies can find further details on the SR9009 vs. Cardarine comparison page at chemyosarms.us.

Frequently Asked Questions

For researchers also studying SARMs and other androgen receptor-targeting compounds, see the complete SARM research guide at chemyosarms.us for comprehensive coverage of the selective androgen receptor modulator class.