Research Peptide Glossary: Key Terms Explained

Product pages, labels and certificates of analysis for research peptides use a lot of technical shorthand. This glossary explains the terms you are most likely to meet, in plain English.

Peptide basics

• Amino acid. The building blocks of peptides and proteins. There are 20 standard amino acids.
• Peptide. A short chain of amino acids joined by peptide bonds. Longer chains are generally called proteins.
• Sequence. The order of the amino acids in a peptide. It defines which peptide it is.
• Tripeptide / pentadecapeptide. Names for peptides by length: three amino acids (for example GHK) or fifteen (for example BPC-157).
• Synthetic peptide. A peptide made in a laboratory by joining amino acids chemically, rather than extracted from a natural source.

Formats and handling

• Lyophilised. Freeze-dried. The peptide is supplied as a dry powder or "cake" in a sealed vial. See lyophilised peptides explained.
• Reconstitution. Dissolving a lyophilised peptide in a measured volume of liquid before analysis.
• Diluent. The liquid used for reconstitution, for example bacteriostatic water.
• Bacteriostatic water. Sterile water containing a preservative (commonly 0.9% benzyl alcohol), so a vial can be accessed more than once.
• Pre-filled pen. A device supplied with the compound already in solution. See peptide pens vs vials.
• 2–8°C. Refrigerated storage, the range printed on many labels.

Units

• mg (milligram). One thousandth of a gram.
• mcg or µg (microgram). One thousandth of a milligram, so 1mg = 1,000mcg.
• ml (millilitre). A unit of volume. Concentration is often written as mg/ml.

Testing and documentation

• CoA (certificate of analysis). A document recording the test results for a specific batch. See what a certificate of analysis tells you and our certificates of analysis.
• Batch or lot number. The identifier that links a physical vial or pen to its production run and its CoA.
• HPLC (high-performance liquid chromatography). A technique that separates the components of a sample. It is commonly used to estimate purity.
• Mass spectrometry (MS). A technique that measures the mass of molecules. It is used to confirm a peptide's identity.
• Purity (%). The proportion of the sample that is the target peptide, as measured by the stated method.
• Third-party testing. Analysis carried out by an independent laboratory rather than by the manufacturer or seller.

Regulation

• RUO (research use only). Supplied for laboratory research, not for human or veterinary use. Read our research use disclaimer.
• WADA Prohibited List. The list of substances banned in sport by the World Anti-Doping Agency. Several research peptides appear on it.

Ready to browse? See our research peptide range, or read our checklist for buying research peptides in the UK.

Frequently asked questions

What is the difference between mg and mcg?

A milligram (mg) is 1,000 times larger than a microgram (mcg or µg). So 5mg is the same as 5,000mcg.

What does HPLC purity mean on a CoA?

It is the share of the sample identified as the target peptide by high-performance liquid chromatography. The figure applies to the batch that was tested.

What does research use only mean?

The product is supplied for laboratory research and must not be used in humans or animals.