SLU-PP-332

What is SLU-PP-332?

SLU-PP-332 is an exercise mimetic that works through a different mechanism than AICAR or MOTS-c. Where those compounds activate AMPK — which then drives downstream exercise adaptation genes — SLU-PP-332 activates ERRα (estrogen-related receptor alpha) and ERRγ directly. ERRα and ERRγ are transcription factors that control the expression of hundreds of genes involved in mitochondrial biogenesis, oxidative metabolism, and endurance adaptation. They're downstream of AMPK and PGC-1α in the exercise signaling cascade — but SLU-PP-332 hits them directly without needing the upstream AMPK activation.

The preclinical results from the Burris lab at Saint Louis University were striking: sedentary mice treated with SLU-PP-332 for 4 weeks showed significant improvements in running capacity — alongside increased mitochondrial density in muscle, improved fat oxidation, and better metabolic profiles. The compound also showed benefits in a heart failure model, where ERRα/γ activity declines as the failing heart shifts from fat to glucose as its primary fuel.

The honest picture: compelling initial preclinical data from a single lab, no independent replication published, zero human data. SLU-PP-332 is earlier-stage than even MOTS-c in the evidence hierarchy. It's being used by biohackers based on the initial papers alone — with the appeal being a genuinely different mechanistic entry point that may stack additively with AMPK activators like AICAR and MOTS-c.

How it works

ERRα/γ Activation — Direct Transcription of Exercise Genes

Estrogen-related receptors α and γ (ERRα, ERRγ) are orphan nuclear receptors — transcription factors that bind DNA and control gene expression without requiring a natural hormone ligand. They regulate hundreds of genes involved in: mitochondrial biogenesis (via PGC-1α coactivation), oxidative phosphorylation enzyme expression, fatty acid oxidation, and glucose metabolism. ERRα activity is essential for exercise adaptations in skeletal muscle and cardiac muscle — ERRα knockout mice have severely impaired exercise capacity, less than 50% of wild-type running distance.

How SLU-PP-332 Differs from AICAR and MOTS-c

The exercise cascade runs: AMPK activation → PGC-1α upregulation → ERRα/γ coactivation → exercise gene expression. AICAR activates AMPK (upstream, via ZMP). MOTS-c activates AMPK (upstream, via folate cycle). SLU-PP-332 bypasses all of that and directly activates ERRα/γ — the transcription factors at the downstream end. This means SLU-PP-332 can drive exercise gene expression in contexts where upstream AMPK signaling may be blunted — and may produce additive effects when combined with AMPK activators, since different steps of the same cascade are being targeted.

Cardiac Application

In heart failure, the failing heart progressively loses its ability to use fatty acids as fuel and becomes dependent on glucose — a metabolically less efficient state. ERRα/γ activity drives fatty acid oxidation capacity in cardiomyocytes. SLU-PP-332 in heart failure models improved cardiac metabolic efficiency and function by restoring ERRα/γ-driven fat oxidation. This cardiac mechanism is independent of and distinct from hexarelin's CD36/GHS-R1b cardioprotective approach.

What the research shows

What the community reports

Common misconceptions