Research Sourcing
99% Pure Does Not Mean You Got 5 Milligrams. Almost Nobody Checks The Second Number.
Purity and quantity are two different tests. A vial can pass one and say nothing about the other. Most certificates only print the first. Here is how to find out what you actually paid for.
View the listing and its certificate →
You buy a 5mg vial. The label says 99% pure. So you assume the vial holds 5 milligrams of peptide, and that peptide is 99% the right molecule.
That is not what those two numbers mean together.
Purity is a ratio. It answers one question: of the peptide that is in here, how much of it is the right molecule? It is a percentage of the peptide. It is not a measurement of how much peptide there is.
Net peptide content is an amount. It answers the other question: how many milligrams of actual peptide are in this vial?
A vial can be 99% pure and still hold noticeably less than the number on the label. Both things can be true at the same time. Only one of them usually gets printed.
Veloura reports both numbers on every lot.
Purity and net peptide content, on the same certificate, tied to the lot number on your vial.
Visit the research store →1A percentage cannot tell you an amount
Think about a glass of orange juice. You can say the juice is 99% pure, meaning almost none of it is anything other than orange juice. That tells you nothing about whether the glass is full.
Peptide vials work exactly the same way. Purity describes the contents. It does not measure them.
Purity says what it is. Net content says how much. You want both numbers.
2The missing weight is not peptide
Peptides come out of manufacturing with things attached. Usually residual salts from the process, plus water the powder pulls in from the air. Those are not contaminants exactly, and they do not lower a purity figure, because purity is only looking at the peptide fraction.
But they take up weight in the vial. The label says 5mg. If a meaningful share of that weight is salt and water, the peptide you paid for is the part that is left.
Weight in the vial and peptide in the vial are not the same measurement.
3Why the second number is usually missing
Because it costs more to produce. Purity comes off a standard run. Net peptide content takes an additional quantitative method, and a lab has to be asked to run it and report it.
A supplier who never orders that test has nothing to hide and nothing to show. They simply do not know either. Neither do you.
A missing number is not proof of anything. It is the absence of proof, which is the problem.
4On a two-compound vial it happens twice
Plenty of vials in this category hold two peptides. The label reads something like 5MG / 5MG. That is two separate amount claims on one line of text.
If a single vial with one compound rarely gets a net content figure, a vial with two almost never gets two of them. The ratio printed on the label is the claim. The certificate is supposed to be the proof.
Two numbers on the label should mean two numbers on the certificate.
Sample format. Open any listing to read the real document for that lot.
Every listing publishes its certificate.
Identity, purity, net content, sterility and endotoxin, signed by the testing laboratory, on the listing itself.
See how every lot is documented →5How to check it in thirty seconds
Open the certificate for the product you are looking at. Do not read it all. Look for one line.
- A line that says net peptide content, or peptide content. If it is not there, the test was not run.
- A result next to it. Either a milligram figure or a statement that it meets the label claim.
- The lot number matching your vial. Otherwise you are reading about a different batch.
- A laboratory name and a date. Signed by the lab, not by the seller.
Four things. Under a minute. It is the single fastest way to separate suppliers in this category.
| On the certificate | Veloura | Typical supplier |
|---|---|---|
| Purity figure | HPLC, reported | Reported |
| Net peptide content | Measured and verified | Usually absent |
| Identity confirmation | LC-MS, same report | Often absent |
| Tied to your lot number | Published before order | Product-level, reused |
| Certificate you can read before buying | Published on the listing | Email and wait |
6What actually arrives
Every item below is something you can check yourself. None of it asks you to take anyone's word.
- A vial with a lot number printed on it.
- A certificate carrying that same lot number.
- Eight checks on that document. Purity, net content, identity, heavy metals, sterility, endotoxin, batch conformity, documentation.
- A signature from an accredited U.S. laboratory.
- The same document on the listing so you can open it again any time.
Read the numbers first. Then decide.
Open any product, read the certificate for that exact lot, and check the number against the vial when it lands.
Visit the research store →
Comments
Genuinely did not know purity and quantity were separate tests. Went back through three old certificates and not one of them listed content.
Same. I had been comparing suppliers on the purity number alone for about a year.
Checked four suppliers after reading this. Two had no content line at all, one sent a product level PDF, this was the only one where the lot matched.
Ordered twice, four months apart. Both documents identical in format and both listed content. That consistency is what kept me.
Shipping was domestic and tracked, which was a first for me in this category.
The orange juice comparison finally made it click. A full glass and a pure glass are not the same claim.