How to read a peptide COA
Have a COA of your own? Check it privately, in your browser, after the example below.
A COA (Certificate of Analysis) is a lab report about a sample from a specific batch of a peptide. It tells you what a laboratory says it tested and found. It does not, on its own, tell you what is in the vial in front of you. If a seller will not provide one, treat that as a red flag.
Explore a real COA, one part at a time
A third-party document, shown unaltered. This certificate of analysis was published by the testing lab Freedom Diagnostics for GHK-Cu 50mg, lot GHK0001. PepCaddie did not write it, has not checked its claims, and does not endorse the company named on it. The explanations are PepCaddie’s. Open the original on the lab’s site (PDF).
This is an interactive lab report. Every part of it is explained in plain words further down this section.
The interactive report needs JavaScript. Every explanation is written out below.
What each part of the report means
The title
What am I looking at?
The name of the document. A certificate of analysis, or COA, is a lab’s report on a sample someone sent it: what was tested, how, and what the lab found.
What does it say?
Printed on the document:
- Certificate of Analysis
That this page is the lab’s report of its results.
What does it not tell me?
A title is just a heading. It does not show that the report is genuine, or that any product is fit to use.
The lab and its contact details
What am I looking at?
Who issued the report. The lab’s logo is at the top left. Its web address and email appear at the top right and again at the bottom. “Proudly Owned and Operated in the USA” is the lab’s own slogan.
What does it say?
Printed on the document:
- FreedomDiagnosticsTesting.com
- Admin@FreedomDiagnostics.net
- Proudly Owned and Operated in the USA
Picture on the document:
- The lab’s logo, a picture that reads “FREEDOM DIAGNOSTICS”.
That Freedom Diagnostics says it produced this report.
What does it not tell me?
A logo and a web address can be copied onto any page, so they do not prove who made it. The document does not say whether the lab is independent of the company that sent the sample, and it lists no accreditation.
To ask the lab about a report, use contact details you find yourself.
The photo of the vials
What am I looking at?
A photo of two vials, printed on the report beside the sample details.
What does it say?
Picture on the document:
- A photo of two vials. One label reads “VERATIS”, “THRIVE”, “GHK-Cu” and “50MG”. The other shows a QR code and “LOT: GHK0001”.
The lot number on the vial label in the photo, GHK0001, is the same as the lot printed on the report.
What does it not tell me?
A photo shows what some vials looked like. It does not show that these were the vials tested, or that your vial came from the same batch.
The QR code on the vial label is too small in this photo to read, so PepCaddie could not check where it points.
Who asked for the test
What am I looking at?
The client is the customer who asked the lab to run the tests.
What does it say?
Printed on the document:
- Client: VERATIS
The tests were requested by Veratis, the company that sells this product.
What does it not tell me?
It does not say how the sample was chosen. A seller choosing which vial to send is not the same as someone buying one at random.
The lab’s reference numbers
What am I looking at?
The lab’s own reference numbers for this job, like an order number. The search code is the accession number with the client’s name in front.
What does it say?
Printed on the document:
- Accession #: 2609210570
- Search Code: VERA2609210570
This report’s number at the lab is 2609210570.
What does it not tell me?
A number on its own cannot show that a report is genuine. It only helps if you ask the lab directly, using contact details you look up yourself.
The dates
What am I looking at?
Received is when the sample arrived at the lab. Reported is when the lab issued its results. They are written month first: September 21 and September 23, 2026.
What does it say?
Printed on the document:
- Received: 9/21/2026
- Reported: 9/23/2026
The lab received the sample two days before it reported the results.
What does it not tell me?
The document has no manufacture date, expiry date, or storage instructions. The results describe the sample when it was tested, not how it was kept afterwards.
The lot number
What am I looking at?
The lot, or batch, number: the code for one production batch. It is the part you can compare with the label on a vial.
What does it say?
Printed on the document:
- Lot: GHK0001
This report is about lot GHK0001. The same code appears on the vial label in the photo.
What does it not tell me?
If your vial’s label shows the same code, the two labels match. That is all it shows. It does not prove what is inside your vial, or that your vial came from the sample the lab tested.
The summary box
What am I looking at?
A quick overview. Several results appear here first, and again further down under Analytical Results.
What does it say?
Printed on the document:
- Sample Summary
For purity and for content, this box lists two separate measurements, “Sample 1” and “Sample 2”. The results table further down gives one figure for each.
What does it not tell me?
The document does not say what Sample 1 and Sample 2 were: for example, two vials, or two runs of the same vial.
The product name
What am I looking at?
The product the sample was sent in as. GHK-Cu is a small peptide, a chain of three amino acids, bound to copper. 50mg is the amount in the product’s name.
What does it say?
Printed on the document:
- Product: GHK-Cu 50mg
The sample was sent in as GHK-Cu, 50 mg.
What does it not tell me?
A product name is what someone wrote on the order. The identity test is the part where the lab checked what it found.
Purity
What am I looking at?
Purity from a machine called HPLC, which separates a sample into its parts. A UV light detector, the “UV” in HPLC-UV, measures each part as it comes out.
What does this result say?
Printed on the document:
- Purity:
- Sample 1: 99.56%
- Sample 2: 99.71%
- Purity (HPLC-UV) 99.64%
Of everything the detector picked up, the lab reports that 99.56% (sample 1) and 99.71% (sample 2) was the main ingredient.
The results table gives 99.64%. That matches the average of the two, rounded, but the document does not say how it was worked out.
What does it not tell me?
A purity percentage describes one test result. It is not a percentage of safety, and it is not the amount of powder in the vial.
It cannot count things the detector does not see, such as water, salts, or germs.
Identity
What am I looking at?
The identity test checks what the sample is. LC-MS separates the sample, then weighs its molecules. Each substance has a known weight, so a match is evidence of what is there.
What does this result say?
Printed on the document:
- Identity: Confirmed
- Identity (LC-MS) GHK-Cu
The lab writes the identity as “Confirmed” in the summary box and “GHK-Cu” in the results table. The Mass Confirmation chart further down shows the measurements it refers to.
What does it not tell me?
It describes the sample the lab received, not your vial. It does not say how much is there, or what else might be mixed in.
Net content
What am I looking at?
Net content is how much of the peptide the lab measured, by weight, in what it tested.
What does this result say?
Printed on the document:
- Net Content:
- Sample 1: 57.21 mg
- Sample 2: 56.51 mg
- Net Content 56.86 mg
The lab reports 57.21 mg (sample 1) and 56.51 mg (sample 2). The results table gives 56.86 mg, the average of the two.
The product name mentions 50mg, so the measured amounts are higher than the name.
What does it not tell me?
The document does not name the method used for this measurement. It describes what the lab tested; another vial may hold a different amount.
Appearance
What am I looking at?
What the sample looked like. Lyophilized means freeze-dried.
What does this result say?
Printed on the document:
- Appearance: Blue Lyophilized Powder
The sample was a blue, freeze-dried powder. GHK-Cu contains copper, which is what makes it blue.
What does it not tell me?
Appearance is a description, not a chemical test. It cannot tell you what something is or how pure it is.
Endotoxin
What am I looking at?
Endotoxins are pieces of the outer layer of certain bacteria. They can remain after the bacteria are dead, and they can cause fever.
The LAL test (Limulus Amebocyte Lysate, made from horseshoe crab blood cells) detects them. USP <85> is the published standard method for this test.
What does this result say?
Printed on the document:
- Endotoxin Threshold: Pass
- Method: Endotoxin testing performed using Limulus Amebocyte Lysate assay in accordance with USP <85> under validated laboratory conditions.
- Endotoxin Replicate 1: Pass
- Endotoxin Replicate 2: Pass
- Assay Sensitivity: ≤0.05 EU/mL
The lab reports the endotoxin threshold as “Pass” in the summary box. It also ran the test twice, called replicates, and reports “Pass” for each.
“Assay Sensitivity: ≤0.05 EU/mL” describes the test itself: it can detect endotoxin down to 0.05 endotoxin units per millilitre. It is not the cutoff used to decide “Pass”.
What does it not tell me?
The document does not print the amount of endotoxin the lab measured, or the numeric cutoff it used to decide “Pass”. PepCaddie has not checked the result.
This is not a sterility test. It does not look for living germs.
Microbial DNA test
What am I looking at?
PCR is a test that looks for the DNA of particular microbes, such as bacteria or fungi, by copying tiny amounts of it until there is enough to detect.
What does this result say?
Printed on the document:
- Microbial Analysis (PCR): Pass
- Method: Microbial detection performed using validated polymerase chain reaction (PCR)-based assay targeting common microbial contaminants.
- Microbial Analysis (PCR) No Detectable Microbial DNA
The lab reports no detectable DNA from the microbes its test looks for, and prints “Pass” in the summary box.
What does it not tell me?
The document does not list which microbes the test targets, or how little it can detect.
Finding no DNA from those targets is not a sterility test, which checks whether anything can grow. PCR also cannot tell living germs from dead ones.
Heavy metals
What am I looking at?
A test for four toxic metals: arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg). ICP-MS is a machine that measures very small amounts of metals.
What does this result say?
Printed on the document:
- Elemental Impurities (ICP-MS):
- As | Cd | Pb | Hg
- Pass
- Elemental Impurities (ICP-MS): Pass — Arsenic, Cadmium, Lead, and Mercury below reporting/specification limits
The lab reports “Pass” for all four, and says they were below its “reporting/specification limits”.
What does it not tell me?
The document does not print the amounts measured or the numeric limits they were compared against, and it does not explain what “reporting/specification limits” means. PepCaddie has not checked the result.
Fentanyl screen
What am I looking at?
A screen for fentanyl, a very strong opioid, as a possible contaminant.
What does this result say?
Printed on the document:
- Fentanyl No Fentanyl Detected
The lab reports that no fentanyl was detected.
What does it not tell me?
The document does not name the method or the smallest amount the screen can detect. “Not detected” means not found at whatever level this test can see.
The results table
What am I looking at?
The detailed results. Each row names a test, often with its method in brackets, and gives the lab’s result.
What does it say?
Printed on the document:
- Analytical Results
- Test
- Result
It repeats identity, purity and net content as single figures, and gives the full wording of the metals result.
What does it not tell me?
A results table only shows the tests the lab ran. Tests that are not in it, such as a sterility test, are not listed on this document.
The method line
What am I looking at?
This line names the method behind the purity and identity results, and the two charts below it.
What does it say?
Printed on the document:
- Method: HPLC with UV detection coupled with mass spectrometry (LC-MS).
The purity figures come from HPLC with a UV detector. The identity result comes from mass spectrometry (LC-MS), which weighs molecules.
What does it not tell me?
It gives no settings, reference standards, or equipment checks. The small print at the bottom describes the purity method differently.
The chromatogram
What am I looking at?
A chromatogram is the picture the HPLC machine draws. Time runs left to right. The height of the line shows how strongly the detector responded, in mAU (milli-absorbance units). Each substance shows up as a peak.
What does it say?
Printed on the document:
- Chromatogram
Picture on the document:
- A line chart. Across the bottom: minutes, from 0.0 to 15.0. Up the side: mAU, from 0 to 500. One tall peak near the start is labelled “GHK-Cu”. The top right corner reads “1 PDA Multi 1”.
There is one tall peak, labelled “GHK-Cu”, near the start, and an almost flat line after it. Purity figures are based on the area under the peaks.
What does it not tell me?
The chart does not print the peak areas, so the purity percentage cannot be worked out from it by eye. PepCaddie has not analysed the chart. “1 PDA Multi 1” is a label from the lab’s software that the document does not explain.
The mass spectrum
What am I looking at?
A mass spectrum, drawn by the mass spectrometer. Left to right is m/z: a molecule’s mass divided by its electrical charge. Each spike is something the machine detected.
What does it say?
Printed on the document:
- Mass Confirmation
Picture on the document:
- A spike chart. Across the bottom: m/z, from about 160 to 1680. Spikes are marked 171.100, 205.100, 293.100 and 341.100. Two carry labels: “GHK-Cu [M+2H]2+” at 171.100 and “GHK-Cu [M+H]+” at 341.100.
Two spikes are labelled GHK-Cu. At 341.100, “[M+H]+” means the molecule with one extra hydrogen and a charge of 1. At 171.100, “[M+2H]2+” means two extra hydrogens and a charge of 2, so it appears at about half the value.
Two other spikes, at 205.100 and 293.100, carry no label.
What does it not tell me?
The document does not explain the unlabelled spikes, and PepCaddie has not analysed the chart. It shows the lab’s measurement of its sample, not of your vial.
The signature
What am I looking at?
A signature above the job title “Principal Chemist”, meaning a senior chemist at the lab.
What does it say?
Printed on the document:
- Principal Chemist
Picture on the document:
- A handwritten signature, placed on the page as a picture.
That someone with that title signed off on the report.
What does it not tell me?
A signature picture can be copied onto any page, so it cannot show that the report is genuine or who wrote it.
The QR code
What am I looking at?
A QR code: a square pattern that holds a web address your phone camera can open.
What does it say?
Picture on the document:
- A QR code inside a small box printed with “SCAN TO VERIFY” and the lab’s name.
PepCaddie read this code. It holds the address of this same PDF on the lab’s website, coas.freedomdiagnosticstesting.com.
What does it not tell me?
“SCAN TO VERIFY” is the lab’s wording. Scanning opens a copy of a file; it does not check the file, and it cannot tell you anything about your own vial.
The small print
What am I looking at?
The lab’s own notes, in the smallest type on the page.
What does it say?
In short, it says five things. The purity analysis was done by “LCMS/MS”. The results apply only to the samples provided. The products are for research use only and not approved for use in people or animals. Results should be read by qualified professionals. And results can be affected by how the sample was handled.
What does it not tell me?
The small print names LCMS/MS for purity, while the results table says HPLC-UV. The document does not explain the difference, which makes it a fair question for the lab.
Not listed on this document
What am I looking at?
Things people often expect on a COA that this document does not include.
What does it say?
There is no separate sterility test, which would check for living germs. The microbial PCR result is a different test: it looks for the DNA of certain microbes.
There is no expiry date, manufacture date, or storage information.
Some details of the listed tests are not printed. Endotoxin and metals are reported as “Pass”, but the amounts measured and the numeric cutoffs used to decide “Pass” are not shown. The fentanyl screen names no method and no detection limit.
The document does not say how the sample was chosen, or whether the lab is accredited.
What does it not tell me?
Not listed means the document says nothing about it, either way. It is not a bad result or a good one.
What a COA usually reports
- Identity: whether the sample the lab received matched the expected molecule. Usually checked by mass spectrometry, which measures molecular weight.
- Purity: how much of what the method detected is the target peptide rather than related impurities. Usually measured by HPLC and shown as a percentage.
- Content: how much peptide the lab measured in the vial it tested, which can differ from the label and from purity.
- Sometimes more, such as endotoxin, sterility, or heavy metals. A test counts only if the report lists it. If it is not listed, you cannot assume it was done.
What to look for
- Who ran the test. A lab name on the report is not the same as an independent lab: the document alone cannot show who chose the sample, who paid, or how the lab relates to the seller.
- A lot or batch number on the certificate that matches the number on your vial. A COA only describes the batch it names, and a matching number shows the two labels agree, not that your vial came from the sample that was tested.
- A purity figure and the method behind it. The number describes the tested sample under that method. There is no universal grade scale, and a high purity figure says nothing about sterility or endotoxin.
Red flags
- No COA available, or "results on request" that never arrive.
- A lot number that does not match your vial, or no lot number at all.
- Only a single purity number with no identity or content testing.
Good to know
- A COA reflects one sample at one point in time. Proper storage after that still matters.
- A COA cannot show that a product is authentic, safe, sterile, or suitable for any use, even when every result on it reads well.
- This is general education, not medical or purchasing advice.
Check my own COA
Have a COA of your own? Choose the PDF, or take or choose photos of its pages, and the decoder finds the same parts on it, explains each one, and shows where it is on your page. It explains the words. It does not judge the document, the product, or the seller.
Your file stays in this browser tab. It is read on this page, text in photos included, and it is not uploaded or sent to PepCaddie, an AI service, or anyone else. It is not saved, and it is gone when you remove it or close the tab. The site's page-view counter is described on the privacy page; it never receives the file.
One PDF, or up to 8 photos or screenshots of its pages (PNG, JPEG or WebP), each up to 25 MB. For photos: lay the page flat in good light, fill the frame, and hold the phone straight above it.
How it reads your COA
- It looks for the same parts as the example above, and shows the line each one came from, so you can check it and correct it.
- Text in a photo, a screenshot or a scanned PDF is read by a text reader that runs in this tab. It makes mistakes, so what it reads is marked as a draft, with the characters to check picked out, until you say it matches your page or correct it.
- "Not listed" means every page of a PDF was read from its own text and nothing mentions it. "Could not read" means the decoder cannot tell. Anything read from a photo or scan is never reported as missing, because the reader may simply have missed it.
- If the text cannot be read reliably, nothing is filled in for you. You type what the document says.
- You can type the batch number from your vial to see whether the same text is on the document. A match is a match of text, nothing more.