Peptide testing labs: what a lab report covers, and what it does not

Short answer: labs that test peptide samples for the public mostly report two things: purity by HPLC and identity by mass spectrometry, with endotoxin, sterility, net content or heavy metals as extra tests [3], [4]. The certificate of analysis that HHS requires for compounded peptides covers more: about a dozen tests, plus the manufacturer’s FDA registration [1], [2]. A lab report on one vial tells you about that vial. It does not make a product legal under the HHS policy.

Two different documents

	Lab report on a vial	COA under the HHS policy
Who orders it	Anyone who sends a sample	The manufacturer of the bulk ingredient
What it covers	The vial that was sent	One batch of ingredient, before compounding
Manufacturer FDA-registered	Not part of the report	Required, with address and FEI number [1], [2]
Grade	Not part of the report. At least one lab says it tests “research use only” peptides [3]	“Intended for human drug compounding” [1]

What labs say they test

From each lab’s own page, checked November 6, 2026:

• Freedom Diagnostics (Franklin, Tennessee) says every COA it issues uses HPLC for purity and LC-MS for identity, lists net content and endotoxin tests, gives a 1 to 3 business day turnaround for most results, and keeps a public COA lookup. Its home page says it tests research-use-only peptides [3].
• Janoshik Analytical (Prague) lists peptide tests in its catalogue, including a $360 blind test for common GLP-1 peptides (semaglutide, tirzepatide and retatrutide) [4].
• Finnrick does not test samples itself. It publishes results from partner labs (BTLabs, Chromate, Freedom Diagnostics, Janoshik and MZ Biolabs) and says it compares overlapping tests to see whether a lab reports higher or lower than its peers [5].

Prices and services change. Confirm them with the lab before you order.

What the HHS standard adds

Appendix B lists the tests a compounding-grade COA should report [1]. Compared with a typical purity-and-identity report, it adds:

• Peptide content (net): how much of the powder is peptide, not water or salt.
• Impurities in detail: each named impurity, any unnamed one, and the total.
• Nitrosamine impurities.
• Residual solvents, residual TFA and fluoride: leftovers from manufacture.
• Elemental impurities: heavy metals, by ICP-MS.
• Counter-ion and water content.
• Bioburden and bacterial endotoxins.

See how to read a peptide COA for the full table.

When a lab report is useful

A lab report can show whether a vial contains the peptide on the label and how pure the sample is by HPLC [3]. It cannot show how the product was made, whether the manufacturer is FDA-registered, or whether the next vial from the same seller matches. Under the HHS policy, those questions are answered by the pharmacy’s ingredient COA and its license [2]. See how to check a compounding pharmacy.

Change log

• November 6, 2026: page created.