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Bench Grade Peptides
Identification·4 min read

Peptide CAS numbers — what they are and how to use them

CAS Registry Numbers for synthetic peptides, how to look them up, and why a supplier's willingness to publish the CAS is a quality-posture signal.

A CAS Registry Number is a unique identifier assigned by the Chemical Abstracts Service to every distinct compound described in the scientific literature. For peptides it is the strongest single identity check available to a buyer, because it resolves to one molecule regardless of what trade name a supplier prints on the vial.

By the Bench Grade Research Team ·

The CAS Registry Number is a unique numeric identifier assigned by the Chemical Abstracts Service to every distinct chemical compound that has been described in the scientific literature. For peptides, the CAS number is one of the strongest identity signals on a product label — it ties the compound on the vial to a specific structure in a regulator-recognized database, independent of any one supplier's naming conventions.

Format and structure

CAS numbers follow the format XXXXXX-XX-X — between four and seven digits, then a hyphen, then two digits, then a hyphen, then a single check digit. The check digit is calculated from the preceding digits, which means a typo in a published CAS number is detectable by anyone who knows the algorithm.

CAS numbers for every compound in the catalogue

The table lists the CAS Registry Number and molecular weight on record for each single-compound product in the current Bench Grade catalogue, so a CAS number search can start here and be checked against CAS Common Chemistry. Blends and compounds with no registry number on record are not listed.

CAS Registry Numbers and molecular weights on record for the current catalogue.
CompoundCAS NumberMolecular weight
5-Amino-1MQ685079-15-6159.21 g/mol
ARA-2901208243-50-81257.32 g/mol
BPC-157137525-51-01419.55 g/mol
Dihexa1401708-83-5504.67 g/mol
DSIP62568-57-4848.81 g/mol
Epitalon307297-39-8390.35 g/mol
GHK-Cu89030-95-5402.92 g/mol
GHRP-2158861-67-7817.95 g/mol
GHRP-687616-84-0873.01 g/mol
Glutathione70-18-8307.32 g/mol
Ipamorelin170851-70-4711.85 g/mol
Kisspeptin374675-21-51302.45 g/mol
LL-37154947-66-74493.27 g/mol
Melanotan-175921-69-61646.86 g/mol
Melanotan-2121062-08-61024.18 g/mol
MOTS-c1627580-64-62174.61 g/mol
NAD+53-84-9663.43 g/mol
Pinealon175175-23-2418.4 g/mol
PT-141189691-06-31025.18 g/mol
Selank129954-34-3751.88 g/mol
Semax80714-61-0813.91 g/mol
SLU-PP-332 5mg303760-60-3290.32 g/mol
SNAP-8 10mg868844-74-01075.17 g/mol
SS-31736992-21-5639.79 g/mol
TB-500 (Long Chain)77591-33-44963.44 g/mol
Tesamorelin218949-48-55135.85 g/mol
Thymosin Alpha-1 5mg62304-98-73108.3 g/mol

How to use the CAS number

  1. Verify a supplier's product against the CAS database (CAS Common Chemistry — commonchemistry.cas.org). Search the CAS number; the listed structure should match the structure the supplier claims.
  2. Reconcile across suppliers. Different vendors use different product names for the same compound; the CAS number is the canonical identifier.
  3. Reference in published protocols. If you are writing up an in-vitro study, citing the compound by CAS plus supplier + lot makes the work reproducible.

Why CAS visibility is a quality-posture signal

A peptide supplier that publishes the CAS number on the product page, on the COA, and on the shipping documentation is making a falsifiable identity claim. The CAS structure is in a public database; if the vial contents do not match the CAS-registered structure, the supplier's identity claim is wrong and any quality posture they build on top of it is undermined. Suppliers that omit the CAS number from their materials are either disorganized or deliberately avoiding the falsifiability — both are signals to look elsewhere.

What Bench Grade publishes

Every single-compound product in the Bench Grade catalog that has a CAS number on record lists it on the product page alongside the molecular weight and formula, and the table above is generated from the same record. Where the issuing laboratory prints it, the CAS number also appears on the lot's Certificate of Analysis. If the CAS number on a product page does not match what you find in CAS Common Chemistry for that compound, contact us — that is a documentation error and we want to fix it.

References

Primary literature for the compounds discussed above. Links open the record on PubMed.

  1. The potential of GHK as an anti-aging peptide Pickart L, et al. Aging Pathobiol Ther. 2022. PMID 35083444 → · summary
  2. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data Pickart L, et al. Int J Mol Sci. 2018. PMID 29986520 → · summary
  3. BPC 157 and Standard Angiogenic Growth Factors. Gastrointestinal Tract Healing, Lessons from Tendon, Ligament, Muscle and Bone Healing Sikiric P, et al. Curr Pharm Des. 2018. PMID 29998800 → · summary
  4. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration Chang CH, et al. J Appl Physiol. 2011. PMID 21030672 → · summary
  5. The mitochondrial-derived peptide MOTS-c is a regulator of plasma metabolites and enhances insulin sensitivity Kim SJ, et al. Physiol Rep. 2019. PMID 31293078 → · summary
  6. The Mitochondrial-Derived Peptide MOTS-c Promotes Metabolic Homeostasis and Reduces Obesity and Insulin Resistance Lee C, et al. Cell Metab. 2015. PMID 25738459 → · summary
  7. The Mitochondrial-Derived Peptide MOTS-c Promotes Metabolic Homeostasis and Reduces Obesity and Insulin Resistance Lee C, et al. Cell Metab. 2015. PMID 25738459 → · summary
  8. Thymosin beta 4 improves dermal burn wound healing via downregulation of receptor of advanced glycation end products in db/db mice Xu TJ, et al. Biochim Biophys Acta. 2014. PMID 25230158 → · summary

Primary sources

Frequently asked questions

Does every research peptide have a CAS number?
Most well-characterised ones do. Newer compounds and multi-component blends often do not, because a CAS number is assigned to a distinct described substance, not to a mixture someone has assembled.
What can a CAS number tell me that a product name cannot?
That two suppliers using different trade names are describing the same molecule, and that the compound exists in the literature at all. Product names are marketing; a CAS number resolves to a single registered substance.
Is a missing CAS number a red flag?
Not by itself, since blends and newer compounds legitimately lack one. A supplier who will not tell you the CAS for a well-known single peptide is a different matter.

Compounds discussed in this guide

More on identification

All products discussed in this guide are supplied by Bench Grade Peptides for laboratory research use only. Not for human or veterinary use.

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