The Peptide Testing Insights Blog

An “HPLC tested” claim means a sample has been analyzed using high-performance liquid chromatography. What that analysis establishes depends on the method and the results reported. A purity result and a measurement of peptide quantity answer different questions. The phrase alone does not tell you which testing was performed. For peptide manufacturers, suppliers, and research

When evaluating tirzepatide, the Certificate of Analysis is one of the most important pieces of documentation associated with the sample. But not all COAs provide the same information. A single high purity percentage may look impressive, but it answers only one analytical question. A more complete COA provides information about what was tested, how the

When evaluating peptide quality, Potency & Purity usually receive most of the attention. But a high purity result does not tell you whether a peptide product contains heavy metals. That’s because peptide purity and heavy metals testing answer completely different analytical questions and require different testing methods. A peptide can have an excellent purity result

“99% pure” is one of the most commonly advertised numbers in the peptide market. But it is also one of the most commonly misunderstood. A high purity percentage can provide valuable information about a peptide sample, but it does not tell you how much peptide is actually present, nor does it evaluate every potential contaminant.

Internal quality control is an important part of peptide manufacturing. In-house testing can help identify production problems, monitor consistency, qualify raw materials, and determine whether a batch meets internal specifications. But when a Certificate of Analysis is being provided to a customer, distributor, or potential business partner, independent third-party testing adds something internal testing cannot:

When submitting peptides for laboratory testing, one of the first questions is usually: How quickly can I get my results? The answer depends on what you’re testing. Peptide potency and purity, endotoxins, microbial contamination, heavy metals, and residual solvents require different analytical procedures. As a result, each test has its own turnaround time. At PharmLabs,

Submitting peptide samples for laboratory testing is straightforward, but proper packaging, labeling, and documentation can make the difference between immediate sample processing and unnecessary delays. Most submission issues are not caused by the analytical testing itself—they result from incomplete paperwork, insufficient sample quantities, mismatched labels, or shipping conditions that compromise sample integrity before the laboratory

When purchasing or manufacturing peptides, one number tends to receive the most attention: purity. It’s often displayed prominently on a Certificate of Analysis (COA), shared with customers, and used as a benchmark for quality. While purity is an important measurement, it answers only one part of a much larger question. A truly comprehensive peptide testing