↳ Research library
Research Peptide Guides
Explore PepDirect's educational library covering research peptides, biochemical compounds, multi-component formulations and the scientific literature surrounding them. Each guide is designed to separate compound identity, mechanism and published evidence from commercial product information.
Research findings are described according to the type of evidence available, including laboratory, preclinical and human research where applicable.
For laboratory research context only.
§ Featured guides
Start with these research guides
Metabolic
What Is Retatrutide?
An overview of retatrutide, triple-receptor agonism and the current research landscape.
Read guide →Metabolic
What Is NAD+?
Learn about NAD+, cellular redox biology and its relationship to NADH, NR and NMN.
Read guide →Blends
What Are Peptide Blends?
Understand multi-component peptide formulations, chemical identity and the difference between ingredient-level and blend-level evidence.
Read guide →§ Browse by topic
Browse by topic
Peptides & Compounds
Guides to individual research peptides and biochemical compounds, identity, mechanism, and the shape of the published evidence.
Compound
What Is GHK-Cu?
The copper-bound tripeptide, GHK vs GHK-Cu identity, copper coordination and the areas studied in laboratory research.
Read guide →Compound
What Is BPC-157?
The pentadecapeptide, research themes, evidence limitations and its relationship to TB-500 and PepDirect blends.
Read guide →Compound
What Is TB-500?
TB-500 identity as PepDirect supplies it, the acetylated thymosin-beta-4 17–23 fragment, versus full-length thymosin beta-4, plus research context.
Read guide →Compound
What Is Semax?
The ACTH(4-7)-derived heptapeptide, sequence, neurobiology research themes and evidence limitations.
Read guide →Compound
What Is Ipamorelin?
The selective growth-hormone-secretagogue pentapeptide, receptor pharmacology, research context and its role in the HULK research blend.
Read guide →Compound
What Is KPV?
The Lys-Pro-Val tripeptide, alpha-MSH relationship, signalling pathways studied and its role in the KLOW blend.
Read guide →Compound
What Is Epitalon (Epithalon)?
The AEDG tetrapeptide, identity, both spellings (Epitalon / Epithalon) and the shape of the published telomerase-associated and gene-expression research.
Read guide →Compound
What Is DSIP?
Delta Sleep-Inducing Peptide, the nine-amino-acid nonapeptide, its historical sleep-neuroscience context and the limits of the published evidence.
Read guide →Compound
What Is PT-141 (Bremelanotide)?
The cyclic melanocortin peptide, identity, MC4R-focused receptor research and its relationship to Melanotan II.
Read guide →Compound
What Is CJC-1295?
The GHRH-analogue research family, CJC-1295 with DAC, CJC-1295 without DAC (Modified GRF 1-29) and why exact chemical identity matters.
Read guide →Compound
What Is Selank?
The tuftsin-derived synthetic heptapeptide, identity, PGP-stability extension and the neurochemical / gene-expression research context.
Read guide →Metabolic Research
Guides covering compounds and pathways studied in metabolic and endocrine research contexts.
Metabolic
What Is Retatrutide?
An overview of retatrutide, triple-receptor agonism and the current research landscape.
Read guide →Metabolic
What Is NAD+?
Learn about NAD+, cellular redox biology and its relationship to NADH, NR and NMN.
Read guide →Metabolic
What Is Cagrilintide?
The acylated amylin analogue, receptor pharmacology (AMY1R/AMY2R/AMY3R), acylation-based pharmacokinetic design and evidence landscape.
Read guide →Metabolic
What Is MOTS-C?
The 16-amino-acid mitochondrial-derived peptide encoded within the mitochondrial 12S rRNA, mitonuclear signalling and metabolic-stress research.
Read guide →Metabolic
What Is AOD-9604?
The hGH C-terminal peptide fragment (residues 176–191), identity, distinction from full-length growth hormone and preclinical lipid-metabolism research.
Read guide →Peptide Blends
Learn how multi-component research formulations are documented and why evidence for individual ingredients does not automatically establish evidence for the exact blend.
Compound Comparisons
Structured comparisons between related research peptides, identity, mechanism and evidence differences.
Comparison
Semax vs Selank
Side-by-side comparison of Semax and Selank, sequences, research histories and how the evidence for each should be interpreted.
Read guide →Comparison
CJC-1295 With DAC vs Without DAC
Structure, terminology and research differences between CJC-1295 with DAC and the peptide commonly labelled 'CJC-1295 No DAC' (Modified GRF 1-29).
Read guide →Comparison
BPC-157 vs TB-500: Research Comparison
Chemical identity, sequence and research differences between BPC-157 (a 15-amino-acid pentadecapeptide) and TB-500 (the acetylated 7-amino-acid thymosin-beta-4 17–23 fragment).
Read guide →Comparison
GLOW vs KLOW Peptide Blends
Side-by-side composition of the GLOW and KLOW research blends, shared components (GHK-Cu, BPC-157, TB-500) and the addition of KPV in KLOW.
Read guide →Comparison
Melanotan I vs Melanotan II
Structure, receptor pharmacology and chemical-identity comparison of Melanotan I (linear α-MSH analogue) and Melanotan II (cyclic melanocortin peptide).
Read guide →Research Methods & Testing
Guides on how to read and interpret peptide research literature, batch-testing paperwork and lot-level documentation.
§ All research guides
Browse all guides
Metabolic
What Is Retatrutide?
An overview of retatrutide, triple-receptor agonism and the current research landscape.
Read guide →Metabolic
What Is NAD+?
Learn about NAD+, cellular redox biology and its relationship to NADH, NR and NMN.
Read guide →Metabolic
What Is Cagrilintide?
The acylated amylin analogue, receptor pharmacology (AMY1R/AMY2R/AMY3R), acylation-based pharmacokinetic design and evidence landscape.
Read guide →Metabolic
What Is MOTS-C?
The 16-amino-acid mitochondrial-derived peptide encoded within the mitochondrial 12S rRNA, mitonuclear signalling and metabolic-stress research.
Read guide →Metabolic
What Is AOD-9604?
The hGH C-terminal peptide fragment (residues 176–191), identity, distinction from full-length growth hormone and preclinical lipid-metabolism research.
Read guide →Blends
What Are Peptide Blends?
Understand multi-component peptide formulations, chemical identity and the difference between ingredient-level and blend-level evidence.
Read guide →Compound
What Is GHK-Cu?
The copper-bound tripeptide, GHK vs GHK-Cu identity, copper coordination and the areas studied in laboratory research.
Read guide →Compound
What Is BPC-157?
The pentadecapeptide, research themes, evidence limitations and its relationship to TB-500 and PepDirect blends.
Read guide →Compound
What Is TB-500?
TB-500 identity as PepDirect supplies it, the acetylated thymosin-beta-4 17–23 fragment, versus full-length thymosin beta-4, plus research context.
Read guide →Compound
What Is Semax?
The ACTH(4-7)-derived heptapeptide, sequence, neurobiology research themes and evidence limitations.
Read guide →Compound
What Is Ipamorelin?
The selective growth-hormone-secretagogue pentapeptide, receptor pharmacology, research context and its role in the HULK research blend.
Read guide →Compound
What Is KPV?
The Lys-Pro-Val tripeptide, alpha-MSH relationship, signalling pathways studied and its role in the KLOW blend.
Read guide →Compound
What Is Epitalon (Epithalon)?
The AEDG tetrapeptide, identity, both spellings (Epitalon / Epithalon) and the shape of the published telomerase-associated and gene-expression research.
Read guide →Compound
What Is DSIP?
Delta Sleep-Inducing Peptide, the nine-amino-acid nonapeptide, its historical sleep-neuroscience context and the limits of the published evidence.
Read guide →Compound
What Is PT-141 (Bremelanotide)?
The cyclic melanocortin peptide, identity, MC4R-focused receptor research and its relationship to Melanotan II.
Read guide →Compound
What Is CJC-1295?
The GHRH-analogue research family, CJC-1295 with DAC, CJC-1295 without DAC (Modified GRF 1-29) and why exact chemical identity matters.
Read guide →Compound
What Is Selank?
The tuftsin-derived synthetic heptapeptide, identity, PGP-stability extension and the neurochemical / gene-expression research context.
Read guide →Comparison
Semax vs Selank
Side-by-side comparison of Semax and Selank, sequences, research histories and how the evidence for each should be interpreted.
Read guide →Comparison
CJC-1295 With DAC vs Without DAC
Structure, terminology and research differences between CJC-1295 with DAC and the peptide commonly labelled 'CJC-1295 No DAC' (Modified GRF 1-29).
Read guide →Comparison
BPC-157 vs TB-500: Research Comparison
Chemical identity, sequence and research differences between BPC-157 (a 15-amino-acid pentadecapeptide) and TB-500 (the acetylated 7-amino-acid thymosin-beta-4 17–23 fragment).
Read guide →Comparison
GLOW vs KLOW Peptide Blends
Side-by-side composition of the GLOW and KLOW research blends, shared components (GHK-Cu, BPC-157, TB-500) and the addition of KPV in KLOW.
Read guide →Comparison
Melanotan I vs Melanotan II
Structure, receptor pharmacology and chemical-identity comparison of Melanotan I (linear α-MSH analogue) and Melanotan II (cyclic melanocortin peptide).
Read guide →Methodology
How to Read a Peptide Certificate of Analysis
How a peptide COA is structured, lot matching, HPLC purity, chemical identity, and what a single test result does and does not establish.
Read guide →§ Editorial standard
How PepDirect research guides handle evidence
Laboratory
In-vitro and biochemical studies investigating molecular or cellular mechanisms.
Preclinical
Animal and experimental models used to investigate biological pathways and compound behaviour.
Human research
Clinical or human research where published evidence exists. Human findings are not inferred from laboratory or animal evidence.
Each guide should identify the type and limitations of the evidence being discussed.
↳ Research products
Looking for research compounds?
Product pages contain current format, amount, lot and Certificate of Analysis information for PepDirect research materials.