How research peptides are tested.

One question per test.

Results from Helion's ILS Laboratories report COA-2026-955706, in the COA Portal.

Purity is a ratio, not an identity.

High-performance liquid chromatography separates the components of a sample as it moves through a column, and a detector draws each one as a peak. Purity is the main peak's share of the total peak area. It says how much of the material is one substance, not which substance: a pure sample of the wrong peptide still reads as pure, which is why identity is tested separately.

The smaller peaks are usually close relatives of the target: truncated or incomplete sequences from synthesis, and oxidized, deamidated or isomerized forms that appear in storage. One mass spectrometry study of a single synthetic peptide characterized one process impurity and thirty-two degradation products.

Identity by mass.

Mass spectrometry measures the mass of the molecules in a sample. When the measured mass matches the peptide's calculated mass, identity is confirmed. Coupled to chromatography as LC-MS, it can also identify the impurities behind the smaller HPLC peaks, and reviews of synthetic peptide analysis treat LC-MS as the core tool for both jobs. To get a sequence's expected mass, use the peptide molecular weight calculator. To read a sequence directly, see Edman degradation and peptide sequencing.

How much is actually in the vial.

The label states an amount of peptide; a content test measures it. The gap can be large: a published analysis of peptide vials bought from three online shops, each sold as 10 mg, measured between 4.3 and 8.8 mg. Helion's reports state the measured content next to the labeled amount, and purity vs net peptide content explains how the two numbers differ.

What is endotoxin?

Endotoxin is lipopolysaccharide from the outer membrane of Gram-negative bacteria. It can remain in a sample after the bacteria themselves are gone, so a sterile result does not rule it out. The Limulus amebocyte lysate (LAL) test is the most widely recognized pharmacopeial method for detecting it, and results are reported in endotoxin units (EU), usually per milliliter of the tested sample: Helion's CJC-1295 + Ipamorelin lot 335XA measured 0.081 EU/mL. Endotoxin testing and the LAL test covers the method in full.

No growth.

Sterility is a separate test: the sample is cultured, and a passing result is no growth. Because endotoxin can outlast the bacteria that made it, reports list the two results separately. Sterility testing explains the media, the 14-day incubation and what a pass means.

Who tests research peptides.

Independent labs like these test samples for suppliers, and some also take samples from individual researchers. Whoever ordered the test, a report should name the lab and the lot, and the lab should be able to confirm it. The COA verification guide walks through checking a report, and the COA reading guide explains each line.

What Helion publishes.

Every published Helion report comes from ILS Laboratories and names its lot. Each covers identity, HPLC purity and endotoxin, and the peptide reports add measured content, sterility and heavy metals. Purity on Helion's published lots runs from 99.63% to 99.92%, against the lab's 95.0% specification. Each report has a Verify at ILS link in the COA Portal and on its product page, and products whose reports are still pending say so.

Specs and storage by compound.