A lab manager opening a certificate of analysis for the first time tends to look at one number: purity. It is a sensible place to start and a poor place to stop. A purity figure with no lot number, no stated method and no link to the vial on the bench is a claim, not a record. Buyers learn quickly to ask for the paperwork behind the number, and the questions they ask reveal a good deal about how a supplier really operates. Vive Peptides, a US-based supplier of research-grade peptides whose products are compounded at a US-based lab that adheres to cGMP standards, makes a useful case study.
Sermorelin, as listed by the research supplier Vive Peptides, serves as the worked example throughout. Everything here concerns laboratory materials. Vive Peptides sells everything strictly for laboratory and research use only, and none of it is approved for human consumption. Nothing in this article describes use in people or animals, and nothing should be read that way.
What does high-purity sermorelin mean on paper?
High-purity sermorelin, on paper, means a specific lot with a measured HPLC purity of 99% or higher, reported by a named method at a named laboratory. The phrase on a product page is a starting point, and the certificate for that lot is the evidence. Vive Peptides lists a purity specification of 99% or higher by HPLC, and every lot is analyzed by an independent USA-based laboratory using HPLC with UV detection coupled to mass spectrometry, so the stated figure can be checked against a record.
Identity matters as much as purity. According to the isolation work of Roger Guillemin’s group and of the Salk Institute group of Jean Rivier and Wylie Vale, growth hormone releasing hormone was first isolated in 1982 from pancreatic tumors, and nearly full activity sits in its first 29 residues. Sermorelin is that 29-residue fragment, GHRH(1-29) amide. A buyer holding a vial labeled sermorelin should expect paperwork that confirms this identity, not just a percentage.
What does a certificate of analysis actually need to show?
It needs to show that one specific lot was measured by a named method, with a result a buyer can match to the vial in hand. Vive Peptides keeps a public certificate library searchable by peptide, lot number or size, and as of October 2026 it holds 126 certificates across 25 peptides.
HPLC, high-performance liquid chromatography, separates a sample into its components and reports how much of the signal belongs to the target compound. A certificate that gives a percentage but omits the method leaves the reader guessing what was measured. The reference most laboratories lean on is United States Pharmacopeia General Chapter <621> Chromatography, which sets system suitability checks such as peak resolution, tailing factor and the precision of repeated runs of the same sample before a purity result is trusted.
Three details separate a useful certificate from a decorative one:
- The lot number printed on the certificate matches the lot number on the label.
- The fill size is stated, because a smaller vial and a larger vial are different production events even when the compound is identical.
- The testing laboratory is identified, and it is independent of the party selling the material.
Why does the lot number matter more than the product name?
Because the product name describes what a supplier intends to sell, while the lot number describes what was actually made. Two lots of the same peptide can differ in measured purity, in fill, in manufacturing date and in the batch of raw material behind them. Research that depends on reproducibility needs traceable materials, and a lab that cannot trace a vial to a lot cannot fully report what it used.
That is why lot-level records are worth more than a single sitewide purity banner. A banner is a promise about a range of products. A lot certificate is evidence about one batch. Sitewide language such as cGMP adherence at a US-based lab tells a buyer where to look, and the lot certificate tells the buyer what was found.
Which specifications should be published for each compound?
At minimum, the identity details a chemist would use to confirm they are holding the right material. A technical profile lets a purchasing officer and a principal investigator work from the same facts.
The sermorelin profile on the Vive Peptides product page is a useful template. The published specifications are:
- CAS number: 86168-78-7
- Molecular formula: C149H246N44O42S
- Molecular weight: approximately 3357.9 g/mol
- Appearance: white lyophilized powder
- Purity: 99% or higher by HPLC
- Storage: -20°C, desiccated, protected from light
Each line answers a question a reviewer would otherwise have to chase. The molecular weight lets an analyst confirm identity against mass spectrometry data, and the appearance gives a quick visual check on receipt.
| Document | What it tells the buyer | Common gap to watch for |
| Certificate of analysis | Measured purity for a named lot and fill size | Missing method, missing lot, or no testing laboratory named |
| Technical profile | CAS number, formula, molecular weight, appearance | Specifications that differ from the certificate |
| Storage statement | Temperature, moisture and light conditions | Vague wording such as “store cool” |
| Use statement | Whether the material is sold for research only | Ambiguous language about intended use |
How should a lab judge storage claims?
By asking whether the stated conditions are specific enough to follow and consistent from the label to the product page. Lyophilized, or freeze-dried, peptides are generally more stable as a dry powder than in solution, which is why they ship in sealed vials. The sermorelin listing calls for -20°C, desiccated and shielded from light. Those three conditions address temperature, moisture and photodegradation, which are the usual enemies of a peptide on a shelf.
A supplier can state the right conditions, but the material is only as stable as the receiving bench makes it, so the lab should have freezer space and a desiccated container ready before the order arrives.
What does “research use only” mean in practice?
It means the material is a laboratory reagent and nothing else. Vive Peptides sells sermorelin strictly for laboratory and research use only, and it is not approved for human consumption.
For a purchasing department, this language does real work. It defines which departments should handle the order and what documentation belongs in the file. A supplier that is vague here deserves more scrutiny than one that repeats the restriction on every page, because a repeated restriction is easier to audit than a stray disclaimer buried in a footer.
A short checklist before the order goes out
Experienced buyers tend to run the same few checks, and none of them take long:
- Look up a certificate by lot number and confirm the method and purity are stated.
- Compare the product page specifications against the certificate for consistency.
- Confirm the independent testing laboratory and its location.
- Read the storage conditions and make sure the receiving lab can meet them on arrival.
- Check that the research-use-only language appears clearly and more than once.
The habit behind all of it is reading every purity claim as a question until a record answers it. Suppliers that publish lot-level certificates, full technical profiles and plain research-use language make that habit easy. Suppliers that do not are telling buyers something too.
