Dorsomorphin (Compound C): Precision AMPK Inhibitor for Translational Research

Executive Summary: Dorsomorphin (Compound C) is a cell-permeable, reversible ATP-competitive inhibitor of AMP-activated protein kinase (AMPK) with a Ki value of 109 nM, exhibiting strong selectivity over related kinases (APExBIO). It also inhibits bone morphogenetic protein (BMP) signaling by blocking Smad 1/5/8 phosphorylation, with an IC₅₀ of 0.47 μM for BMP4-induced SMAD phosphorylation. Dorsomorphin suppresses downstream AMPK effectors such as acetyl-CoA carboxylase (ACC) phosphorylation by 80%, and reduces autophagic proteolysis. It is used extensively to study metabolic regulation, muscle atrophy, neural stem cell differentiation, and iron metabolism in both in vitro and in vivo models (Ren et al., 2025). The compound is insoluble in water and ethanol but dissolves in DMSO to ≥8.49 mg/mL with warming and sonication.

Biological Rationale

AMPK is a master regulator of cellular energy homeostasis, sensing AMP/ATP ratios and orchestrating metabolic adaptation. Disruption of AMPK signaling is implicated in diseases such as obesity, diabetes, cancer, and muscle atrophy (Ren et al., 2025). The BMP/Smad pathway governs cell fate, neural induction, and bone formation. Dorsomorphin (Compound C) enables precise inhibition of these pathways, allowing researchers to dissect their independent and intersecting roles in physiology and disease. Its chemical specificity offers advantages over genetic knockdown—providing temporal control and reversibility. Use of Dorsomorphin supports mechanistic studies in metabolic adaptation, autophagy regulation, and regenerative biology.

Mechanism of Action of Dorsomorphin (Compound C)

Dorsomorphin is a small-molecule ATP-competitive inhibitor of AMPK, binding the kinase domain with a Ki of 109 nM. It demonstrates marked selectivity for AMPK over protein kinase A, protein kinase C, and Janus kinase 3 (APExBIO). Inhibition of AMPK prevents phosphorylation of key substrates, notably ACC, resulting in suppressed fatty acid oxidation and altered autophagic flux. Dorsomorphin also acts on the BMP/Smad pathway—blocking BMP type I receptor-mediated phosphorylation of Smad 1/5/8, thereby reducing transcription of hepcidin and modulating iron metabolism. This dual-pathway inhibition enables simultaneous interrogation of metabolic and differentiation signaling (see also: Dorsomorphin and mitochondrial biology). This article extends the mechanistic scope discussed in that reference by detailing downstream metabolic and autophagic readouts.

Evidence & Benchmarks

• Dorsomorphin inhibits AMPK in vitro with a Ki of 109 nM, and suppresses downstream ACC phosphorylation by 80% in hepatocytes (APExBIO, product page).
• Suppresses AMPK/PINK1/Parkin-mediated mitophagy in skeletal muscle, as demonstrated by reversal of Lycium barbarum polysaccharide effects in HFD-induced muscle atrophy models (Ren et al., 2025, DOI).
• Blocks BMP4-induced phosphorylation of Smad 1/5/8 with an IC₅₀ of 0.47 μM in cultured cells (APExBIO).
• Reduces hepatic hepcidin mRNA and increases serum iron in animal models, supporting applications in iron metabolism research (APExBIO, product page).
• Induces dorsalization in zebrafish embryos at concentrations used for BMP pathway inhibition (APExBIO, product page).
• Recommended for use at 4–40 μM in cell culture, and 10 mg/kg intraperitoneally in rodents, with rapid solution preparation in DMSO (APExBIO, product page).
• Experimental benchmarks demonstrate blockade of AMPK-induced autophagy, as measured by LC3-II/I ratio and mitochondrial quality control in muscle atrophy models (Ren et al., 2025, DOI).
• For advanced protocol optimization and troubleshooting, see Dorsomorphin: Precision AMPK Inhibitor for Advanced Assays—this article expands the focus to include integrated autophagy and iron metabolism endpoints, not covered in detail previously.

Applications, Limits & Misconceptions

Principal Applications:

• Inhibition of AMPK activity in hepatocytes, muscle, and cancer cell lines.
• Suppression of autophagic proteolysis via AMPK/ACC pathway regulation.
• Modulation of BMP/Smad signaling in stem cell, developmental, and iron metabolism studies.
• Modeling muscle atrophy, metabolic syndrome, and neural stem cell differentiation.

Common Pitfalls or Misconceptions

• Dorsomorphin is not suitable for long-term (multi-day) solution storage; solutions should be used promptly after preparation (APExBIO).
• It is insoluble in water and ethanol, requiring DMSO and gentle warming/sonication for dissolution—incorrect solvent use leads to precipitation and assay failure.
• Not all effects are AMPK-specific; at higher concentrations, off-target activity on BMP signaling and unrelated kinases may occur (Strategic Dual-Pathway Inhibition—this article clarifies concentration-dependent specificity).
• Cell-type and species differences affect sensitivity; empirical titration is necessary for new models.
• Not appropriate for clinical or in vivo therapeutic use in humans; for research use only.

Workflow Integration & Parameters

Dorsomorphin (Compound C) is supplied as a solid, typically by APExBIO (SKU: B3252), and should be stored at -20°C. For use, dissolve at ≥8.49 mg/mL in DMSO with mild warming and ultrasonic agitation. Filter sterilize if required. Recommended working concentrations: 4–40 μM for cell culture (e.g., HeLa, hepatocytes), 10 mg/kg intraperitoneal injection in rodents. Solutions are not recommended for storage beyond 24 hours at 4°C. Rapid loss of potency may occur if exposed to repeated freeze-thaw cycles. Incorporate appropriate vehicle and negative controls in all experiments. For detailed protocol guidance, see Strategic Modulation of Cellular Metabolism—the current article adds new benchmarks and clarifies product handling for high-throughput and in vivo workflows.

Conclusion & Outlook

Dorsomorphin (Compound C) remains a gold-standard ATP-competitive AMPK inhibitor with dual action on BMP/Smad signaling, supporting advanced research in metabolism, autophagy, muscle atrophy, and stem cell biology. Its selective, reversible inhibition enables temporal control in dissecting complex signaling networks, when used at empirically optimized concentrations. The product from APExBIO (B3252) is validated for in vitro and in vivo experimental models, but researchers must observe solvent compatibility and solution stability constraints. Future studies will likely extend its utility in multi-pathway disease modeling and mechanistic dissection of energy-sensing pathways. For additional strategic deployment, see Strategic Modulation of AMPK and BMP Signaling—while that piece emphasizes integrative pathway analysis, this review delivers detailed product handling and updated experimental benchmarks.