A certificate of analysis (COA) is a lab report for one batch of a product. To trust it, check four things: that it identifies the compound (ideally by mass spectrometry, not by HPLC alone), that it measures how much is present as well as how pure it is, that it matches your batch, and that the lab confirms it issued the report. Independent tests of products bought online show why each step matters.
What a COA should contain
For drug ingredients, FDA’s manufacturing guidance says a COA names the product and its batch, lists each test with its acceptance limit and numerical result, and is dated and signed, with the original manufacturer named (FDA Q7). Research products are not made under those rules, but the same fields tell you whether a report is worth anything.
| Field | What to look for |
|---|---|
| Compound and form | The exact substance and salt (for example ostarine, or ipamorelin acetate), not a brand name. |
| Batch or lot number | The same number as on your bottle or vial. |
| Lab name and report ID | A real lab you can find on your own, and a report number you can quote to it. |
| Test date | Recent enough to belong to your batch. |
| Identity test | Mass spectrometry (LC-MS or MS) or another specific method, with the measured mass. |
| Purity | A percentage with the method (usually HPLC) and, ideally, the chromatogram. |
| Amount (assay) | How many milligrams per capsule, milliliter or vial were found, compared with the label. |
| For injectables | Sterility and endotoxin results, which are separate tests from purity. |
HPLC vs LC-MS: what each test answers
High-performance liquid chromatography (HPLC) pushes a sample through a column at high pressure so its parts separate into peaks (NCI). It is good at showing how much of what the detector picks up is one main compound, and that is what a COA’s “purity” figure usually reports. It is weak at proving which compound that is: the international guideline for drug specifications says identification by a single chromatographic retention time is not regarded as specific (ICH Q6A).
Liquid chromatography–mass spectrometry (LC-MS) adds a mass spectrometer, which sorts molecules by mass and so helps confirm what the compound is (NCI). The same guideline accepts combined methods such as HPLC/MS for identification (ICH Q6A). Anti-doping labs use LC-MS for the same reason.
| HPLC (UV detector) | LC-MS | |
|---|---|---|
| Answers | How pure is the main peak? | What is the compound, by mass? |
| Can miss | A different compound that comes off the column at the same time | Purity, unless the lab also measures it |
| Best use | Purity and amount, against a reference standard | Identity, and finding unexpected or undeclared substances |
What purity means, and what it does not
Identity, purity and amount are three different questions, and drug-quality guidelines treat them as separate tests (ICH Q6A). A vial can be “99% pure” and still hold the wrong amount, or the wrong substance:
- When researchers bought semaglutide from illegal online pharmacies, the vials claimed 99% purity. Measured purity was 7.7% to 14.4%, the amount of semaglutide was 29% to 39% above the label, and endotoxin was found in every sample (Ashraf 2024).
- In 44 products sold online as SARMs, 9% contained no active compound, 25% contained substances not on the label, and the amount differed substantially from the label in 59% (Van Wagoner 2017).
- Peptides add their own problems: FDA warns that different salts and molecules are sold under the name TB-500 (FDA 2026), and black-market products have contained a research-grade “His-tagged” form of IGF-1 LR3 (Kohler 2010) and a modified Gly-ipamorelin (Krug 2018).
Red flags on a COA
- No batch number, or a batch number that does not match your product.
- No lab name, address or report number that you can check independently.
- Purity only, with no identity test by mass spectrometry.
- A result with no chromatogram or spectrum, so nothing can be checked.
- The same report shown for every batch, or a test date long before the batch was made.
- A compound, salt or mass that differs from the label.
- An injectable peptide with no sterility or endotoxin result.
How to verify a COA with the lab
- Find the lab’s contact details yourself, not from the PDF.
- Send the report number and batch number and ask whether the lab issued that report with those results.
- Check the lab’s accreditation. Accreditation to ISO/IEC 17025:2017 means an accreditation body has assessed the lab against that standard (NIST’s NVLAP is one such body in the US) (NIST). Check that it is current and covers the method used.
- Compare the result with your label: compound, salt, amount and batch.
What a COA cannot tell you
- It describes one batch, not the next one.
- It says nothing about safety in people. No SARM is an approved medicine, and the FDA says products sold as SARMs are unapproved drugs (FDA).
- It does not make a product legal. Health Canada says “for research use only” labels do not make products legal (Health Canada). See are SARMs legal.
When Sarmguide links to a shop, it is our partner SwissChems. Our SwissChems review explains how we chose it. We do not vouch for any individual batch; use the steps above for every product you look at.