BPC-157, TB-500, Ipamorelin and CJC-1295: Research Peptides Compared

BPC-157 is a 15-residue peptide, GEPPPGKPADDAGLV (Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val), molecular formula C62H98N16O22, molecular weight approximately 1419.5 g/mol. It corresponds to a partial sequence of a protein originally described in gastric juice. No dedicated receptor has been identified; preclinical cell-culture work has examined VEGFR2 and the downstream Akt–eNOS axis, nitric oxide signaling, and FAK-paxillin focal-adhesion signaling in fibroblasts. See the BPC-157 research peptide page for lot documentation.

Thymosin beta-4 (Tβ4) is a 43-amino-acid, N-terminally acetylated peptide encoded by the TMSB4X gene:

Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES

Its molecular weight is approximately 4.96 kDa. Tβ4 binds monomeric (G-) actin in a 1:1 complex and is a major actin-sequestering protein in many cell types. The central motif LKKTETQ (residues 17–23) is part of the actin-binding region. In the research-peptide market, the name "TB-500" is applied both to synthetic full-length Tβ4 and to the short acetylated fragment Ac-LKKTETQ, so the certificate of analysis should state the exact sequence and expected mass. See TB-500 research peptide.

Ipamorelin is a synthetic pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, containing the non-proteinogenic residues α-aminoisobutyric acid (Aib) and D-2-naphthylalanine. Its molecular weight is approximately 711.9 g/mol. It is an agonist of the growth hormone secretagogue receptor type 1a (GHSR-1a), the receptor for the endogenous ligand ghrelin. GHSR-1a is a class A G protein-coupled receptor that signals predominantly through Gq/11, phospholipase C and intracellular calcium mobilization. In its original pharmacological characterization, Ipamorelin was described as a selective GHSR agonist relative to earlier growth hormone-releasing peptides such as GHRP-6.

CJC-1295 is built on GHRH(1-29), the shortest fully active fragment of growth hormone-releasing hormone. It carries four amino acid substitutions (D-Ala2, Gln8, Ala15 and Leu27) that increase resistance to enzymatic cleavage, notably by dipeptidyl peptidase-4 at the N-terminus. Two forms circulate in research catalogues:

• CJC-1295 without DAC (also called modified GRF(1-29)): the tetrasubstituted 29-residue amide, molecular weight approximately 3.37 kDa.
• CJC-1295 with DAC: the same peptide with an added C-terminal lysine bearing a maleimidopropionyl group, which forms a covalent bond with serum albumin in biological matrices.

Both forms act at the GHRH receptor, a class B GPCR that couples to Gs, adenylyl cyclase, cAMP and protein kinase A. Lot documentation for the Ipamorelin combination is on the CJC-1295 (no DAC) / Ipamorelin blend page.

Sermorelin is GHRH(1-29)-NH2, the unmodified 29-residue amide fragment of native GHRH. Tesamorelin is the full 44-residue GHRH sequence with a trans-3-hexenoyl group on the N-terminal tyrosine, a modification that stabilizes it against N-terminal cleavage. Together with CJC-1295 they form a useful series for structure–activity work at the GHRH receptor: native fragment, substituted fragment, and N-acylated full-length analog. See Tesamorelin research peptide.

MK-677 (ibutamoren) is frequently listed alongside these compounds, but it is not a peptide. It is a non-peptide spiropiperidine small molecule that acts as a GHSR-1a agonist. Because its chemistry, synthesis and analytical characterization differ from those of peptides, it is outside the scope of this comparison.

All of the peptides above are supplied as lyophilized solids and are characterized with the same core methods, although the expected values differ:

Beyond identity and purity, laboratories commonly look for peptide content (net peptide relative to counter-ions and residual water), appearance, and, for cell-based assays, an endotoxin result. Lyophilized material is generally stored sealed and dry at −20 °C, protected from light; dissolved material is aliquoted to avoid repeated freezing and thawing.

Because the compounds act on different targets, the choice depends on the experimental question rather than on any ranking:

• Cytoskeleton and actin dynamics: thymosin beta-4 / TB-500.
• Endothelial and focal-adhesion signaling in vitro: BPC-157.
• GHSR-1a (ghrelin receptor) pharmacology: Ipamorelin.
• GHRH receptor pharmacology and structure–activity: Sermorelin, CJC-1295 and Tesamorelin.

For a deeper look at the first two, see our BPC-157 and TB-500 research guide.

Purity and identity data for each lot are published on our Certificates of Analysis page, and our research-only disclaimer sets out terms of sale. NuRev supplies these peptides for laboratory research use only; it is not for human or veterinary use.