About Peptide.Express

How we verify what we sell

The steps below are how to read a certificate that is on file. They are not a claim that every lot received every assay:

1. 1

   Sourcing & supplier qualification

   Compounds are sourced from manufacturing partners that synthesize to research-grade specifications. A supplier certificate is a starting point. A measured result is the figure on a third-party certificate where one is on file.

2. 2

   HPLC purchasing specification (≥99%)

   Lots are sourced against a ≥99% HPLC purchasing specification. The measured purity figure for a listed lot is the value on that lot's Certificate of Analysis, not a rounded catalog percent.

3. 3

   Mass-spec identity, where reported

   Where a certificate reports mass data, liquid chromatography–mass spectrometry (LC-MS) compares the observed molecular weight with the expected mass for the named compound. A missing mass line is not a result, and it is not proof the assay never ran.

4. 4

   Independent third-party testing

   Peptide.Express does not run in-house purity testing. Where a certificate is on file, the laboratory named on it is independent of Peptide.Express.

5. 5

   Certificate of Analysis for the documented lot

   Where a lot is documented, the Certificate of Analysis on file is the record for that lot. It shows the tests that laboratory reported, so a result can be traced to that lot rather than to a catalog average.

See the full methodology on our Quality & Purity Standards page, or browse batch certificates in the Lab Results library.

The standard we publish against

"We care about quality" is not a specification and cannot be checked. What follows is how to read a certificate that is on file. ≥99% by HPLC is the purchasing specification, not a measurement of any one vial:

≥99%HPLC sourcing spec

Reverse-phase C18 chromatography, purity taken as area under the curve. ≥99% is the purchasing specification, not a measurement of any one vial. Where a certificate is on file, the measured purity is the area-percent on that certificate, and it can differ from the specification.

Where reportedIdentity by LC-MS/MS

Where the laboratory reports mass data, the observed molecular weight is compared with the theoretical value for the named compound. Purity says how much of the sample is one species; mass says which species it is.

When reportedLAL endotoxin result

Limulus Amebocyte Lysate assay for Gram-negative bacterial endotoxin. When the laboratory reports it, the figure is on that batch record. Endotoxin is heat-stable and survives sterile filtration, so it is measured rather than inferred from a sterility line.

ZeroIn-house purity tests

Peptide.Express runs none of its own purity analysis. Published purity and identity figures come from the independent laboratory named on the certificate.

1:1Lot-specific CoA

Where a lot-specific certificate is on file, that document describes one synthesis run, not the whole product line. Match the lot on the vial. A product-level PDF is not a substitute for a lot match.

Where the honesty has to sit: HPLC reports purity as a proportion. It does not identify the impurity fraction, and it does not confirm that the dominant peak is the right molecule. A mass result, where the laboratory reports one, is read beside the HPLC figure rather than inferred from it. The methodology, including what each test cannot tell you, is written out on the peptide purity and testing methodology page.

Who we serve

Peptide.Express supplies research compounds to people doing in-vitro laboratory work. That framing is not a disclaimer bolted on at the end — it defines what we sell, how it is documented, and what it is not suitable for.

Research-use-only material is not manufactured to pharmaceutical GMP requirements, is not sterile-filled for injection, and holds no approval from any regulatory body for administration to humans or animals. A Certificate of Analysis documents purity and identity. It is not a safety assessment, and it says nothing about what a compound does in a living organism.

Our research team

Content and product documentation on Peptide.Express is maintained by the Peptide.Express Research Team — staff with working backgrounds in peptide chemistry, HPLC purity analysis, and analytical method validation. The team reviews molecular data, verifies that cited literature studies the named compound, and keeps entity facts (formula, molecular weight, CAS, sequence) consistent across the site. Research articles are attributed to this team and written strictly within a research-use framing.

What we hold ourselves to

About the name

Peptide.Express is a US research-use-only peptide supplier that operates online at peptide.express. Mailing address: 8865 Stanford Blvd, Ste 101, Columbia, MD 21045. Contact: info@peptide.express. Peptide.Express (peptide.express) is not affiliated with any other business that uses a similar name. All products are for laboratory research use only. Not for human or veterinary use.

FAQ

Is Peptide.Express legit?

Peptide.Express publishes the following so researchers can check it directly. Third-party Certificates of Analysis on file are listed by batch, with the testing laboratory named, in the lab results index; products without a certificate on file are marked as awaiting one. The mailing address is 8865 Stanford Blvd, Ste 101, Columbia, MD 21045. The Shipping & Returns policy, Terms of Service and Privacy Policy are published on this site. For laboratory research use only. Not for human or veterinary use.

Research resources we publish

Reference material on this site is written to be usable whether or not you buy anything. Five places to start:

• Peptide research hub — compound guides and mechanism references

  Per-compound reference pages covering structure, molecular weight, receptor targets and named signalling pathways, with the primary literature cited inline.

• Quality and purity testing methodology

  What HPLC measures, what LC-MS/MS adds, how LAL endotoxin testing works, and a field-by-field walkthrough of a Certificate of Analysis.

• Lab results — batch Certificates of Analysis

  Third-party certificates published where documents are on file, so a lot number can be matched to the certificate that describes that lot.

• Peptide reconstitution protocol guide

  Equipment, dissolution technique, a compound-specific diluent volume table, storage windows, and the handling errors that quietly ruin material.

• Peptide reconstitution calculator

  Mass, diluent volume and resulting concentration, worked in both directions.