SLU-PP-332 vs AOD-9604: Mechanism Comparison for Research

SLU-PP-332 and AOD-9604 are two research compounds frequently compared in preclinical metabolic pharmacology, but they belong to entirely different molecular classes and engage entirely different molecular targets. SLU-PP-332 is a small-molecule pan-agonist of the Estrogen-Related Receptor (ERR) family developed at Saint Louis University; AOD-9604 is a synthetic peptide fragment derived from the C-terminus of human growth hormone. This page summarizes the mechanism, target, and research positioning of each compound for the scientific community working in mitochondrial biogenesis and lipolytic-pathway research.

Compound Class and Origin

SLU-PP-332 is a synthetic small-molecule research compound (not a peptide) reported in the published literature out of the Burris laboratory at Saint Louis University. It has been characterized as a pan-agonist of the three Estrogen-Related Receptor isoforms — ERR?, ERR?, and ERR? — which are orphan nuclear receptors structurally related to the classical estrogen receptors but with distinct ligand specificity and physiological roles. SLU-PP-332 has been investigated as a tool compound for probing ERR-driven transcriptional programs.

AOD-9604 (Anti-Obesity Drug 9604) is a synthetic peptide fragment corresponding to amino acids 176-191 of the C-terminal region of human growth hormone (hGH), with an additional N-terminal tyrosine residue added during synthesis. It was developed at Monash University and subsequently advanced through preclinical and clinical research as a research probe for the lipolytic activity ascribed in the literature to that specific hGH fragment, distinct from the somatogenic activity attributed to full-length hGH.

Mechanism of Action: Different Targets Entirely

SLU-PP-332 acts at the level of nuclear-receptor-mediated transcription. As an ERR pan-agonist, it has been investigated in published literature for upregulating gene programs associated with mitochondrial biogenesis, oxidative metabolism, and exercise-mimetic transcriptional signatures. The ERR family — particularly ERR? and ERR? — overlaps with the PGC-1? coactivator network that is central to mitochondrial gene transcription. SLU-PP-332 has accordingly been described in preclinical reports as a research probe for the study of skeletal-muscle and cardiac mitochondrial pathways, oxidative phosphorylation gene sets, and exercise-related transcriptional programs.

AOD-9604 acts through an entirely different mechanism. As a 16-amino-acid peptide fragment of hGH (residues 176-191), its preclinical pharmacology has investigated lipolytic activity on adipose tissue and reduced lipogenic gene expression in rodent models. The peptide was originally characterized as retaining the lipolytic activity of full-length hGH while reportedly lacking the somatogenic, growth-promoting, and insulin-resistance-associated activities of full hGH in published rodent literature. The exact downstream signaling remains an active area of research, with proposed pathways involving beta-adrenergic-related lipolytic signaling cascades.

Researchers studying mitochondrial energetics may also reference MOTS-c as a complementary mitochondrial-derived peptide tool, while those investigating GH-axis fragments often pair AOD-9604 with ipamorelin or CJC-1295 in study design.

SLU-PP-332 vs AOD-9604 Research Comparison

Attribute	SLU-PP-332	AOD-9604
Molecular class	Small-molecule (NOT a peptide)	Synthetic peptide fragment
Origin	Burris laboratory, Saint Louis University	Monash University
Primary target	ERR?, ERR?, ERR? pan-agonism	Lipolytic pathway via hGH 176-191 fragment
Receptor type	Orphan nuclear receptor	Mechanism in active research
Length	Small molecule (sub-1 kDa)	16 amino acids
Research focus	Mitochondrial biogenesis, exercise-mimetic transcription	Lipolytic pathway, adipose research
Coactivator partner of interest	PGC-1? / nuclear receptor network	Beta-adrenergic-associated lipolytic signaling

Estrogen-Related Receptors: The SLU-PP-332 Target Family

The Estrogen-Related Receptors (ERR?, ERR?, ERR?) are members of the NR3B nuclear receptor subfamily. Despite their name, they do not bind classical estrogens; the name reflects sequence homology to the classical estrogen receptors. ERR? and ERR? in particular have been investigated as transcriptional regulators of mitochondrial biogenesis and oxidative metabolism gene programs in skeletal muscle and cardiac tissue. The discovery and validation of ERR-selective agonists has historically been challenging because of the receptors’ originally orphan status; SLU-PP-332 has been positioned in published literature as a useful pan-agonist research tool for probing ERR-dependent transcriptional output.

For laboratories investigating ERR-dependent gene programs, SLU-PP-332 may be paired with PGC-1?-related research probes or compared against selective ERR? or ERR? ligands. The compound is supplied as a research-grade powder for in vitro and preclinical investigation, intended for laboratory and research use only.

The Burris Laboratory and ERR Research Lineage

SLU-PP-332 emerged from the Burris laboratory at Saint Louis University, a research group with a long publication record in nuclear-receptor pharmacology and ERR family characterization. The development of SLU-PP-332 as a useful pan-agonist tool addressed a gap in the published literature: prior to its disclosure, ERR-pathway research was limited primarily to ERR antagonists and inverse agonists, with selective and pan-agonist tools comparatively scarce. The compound has accordingly become a frequently cited tool in the published mitochondrial-biogenesis and exercise-mimetic transcription literature.

For laboratories investigating PGC-1?-driven transcriptional programs, ERR-dependent oxidative metabolism gene sets, or muscle and cardiac mitochondrial pathways, SLU-PP-332 provides a research tool for inducing the ERR-side of that transcriptional axis. The compound is supplied as research-grade powder, intended for in vitro and preclinical investigation only; this site does not provide dosing or human-use information of any kind.

AOD-9604 Fragment Pharmacology

AOD-9604 was investigated in early-stage human research as a candidate for adipose-related research, but development was discontinued and the peptide is now used predominantly as a preclinical research tool. The published rodent literature describes lipolytic activity in adipose tissue with reportedly reduced effect on glucose handling relative to full-length hGH; investigators studying GH-fragment pharmacology, adipose biology, or comparing fragment activity to full hGH may use AOD-9604 as a research probe.

The peptide is typically supplied as a lyophilized powder. Researchers comparing GH-axis peptides may also reference tesamorelin, a GHRH analog, in their study design, though tesamorelin operates upstream at the level of pituitary GH secretion rather than as a downstream fragment. The full research peptide catalog includes additional GH-axis and metabolic compounds.

Analytical Methodology Differences

Because SLU-PP-332 is a small molecule and AOD-9604 is a peptide, the two compounds require different analytical platforms for purity verification. SLU-PP-332 is appropriately characterized by small-molecule HPLC and mass spectrometry methods; molecular-mass confirmation, related-substances analysis, and chromatographic purity all use small-molecule analytical conventions. AOD-9604, as a 16-amino-acid peptide, requires peptide-class HPLC, peptide mass spectrometry (with characteristic charge-state envelopes), and peptide-relevant impurity profiling including incomplete-coupling truncated sequences and oxidation products at residues prone to oxidation.

This analytical-methodology distinction has practical implications for any laboratory verifying the identity and purity of incoming research material. A COA for SLU-PP-332 should be a small-molecule analytical document; a COA for AOD-9604 should be a peptide analytical document. Conflating the two — or accepting a small-molecule-style COA for a peptide product, or vice versa — is a quality-control failure mode that occasionally appears with non-specialty suppliers.

Selecting Between the Two for Research

The two compounds are not interchangeable and should not be conflated: SLU-PP-332 is a small-molecule nuclear-receptor pan-agonist, while AOD-9604 is a peptide fragment of hGH. A research program studying mitochondrial biogenesis, ERR-dependent transcription, or exercise-mimetic gene programs would select SLU-PP-332. A research program studying GH-fragment pharmacology, adipose lipolytic pathways, or comparative hGH activity would select AOD-9604. Some research designs may incorporate both as complementary probes of metabolic pathways at different levels of regulation.

Investigators may also pair these with peptides such as SLU-PP-332 (catalog page) and AOD-9604 for direct sourcing, or compare against GH-axis compounds like CJC-1295 and ipamorelin for upstream GH-axis effects. Browse the complete peptides for sale page for the full lineup.

Frequently Asked Research Questions

Is SLU-PP-332 a peptide?

No. SLU-PP-332 is a small-molecule research compound, not a peptide. It is a synthetic ligand for the Estrogen-Related Receptor family (ERR?, ERR?, ERR?). AOD-9604, by contrast, is a 16-amino-acid peptide fragment.

What does SLU-PP-332 do at the ERR receptors?

SLU-PP-332 has been characterized in published literature as a pan-agonist of all three ERR isoforms. ERR engagement has been investigated as a transcriptional driver of mitochondrial biogenesis and oxidative metabolism gene programs in preclinical models.

What is AOD-9604 derived from?

AOD-9604 corresponds to the C-terminal fragment of human growth hormone, residues 176-191, with an added N-terminal tyrosine. It was developed to investigate whether the lipolytic activity ascribed to that fragment of hGH could be studied separately from the somatogenic activity of full-length hGH.

Are SLU-PP-332 and AOD-9604 in the same research category?

Both are studied in metabolic research, but they are mechanistically distinct. SLU-PP-332 is a transcriptional agonist of the ERR nuclear receptors. AOD-9604 is a peptide fragment investigated in adipose lipolytic pathway research. They are not substitutes for one another.

What purity standard should research SLU-PP-332 and AOD-9604 meet?

For quantitative preclinical work, both should meet HPLC-verified purity at or above 99% with a per-lot Certificate of Analysis. Proxiva supplies both at 99.9% verified purity with batch-specific COA included with each order.

Can SLU-PP-332 and AOD-9604 be co-investigated in the same research model?

Yes, study designs can include both as complementary probes of metabolic pathways at different regulatory levels — SLU-PP-332 acting at nuclear-receptor transcription, AOD-9604 acting via GH-fragment lipolytic pathways. Each is supplied as a separate research-grade product with its own COA.

Source High-Purity Research Peptides

Quality, purity, and provenance directly determine experimental outcomes. Proxiva Peptides supplies all compounds at 99.9% verified purity with HPLC analysis and Certificate of Analysis included on every batch. Browse the full research peptide catalog.

All products are for laboratory and research use only. Not for human consumption.