The essential peptide vocabulary

Finding your way through documents and product sheets means knowing a few key terms. Here is an annotated mini-lexicon to start on solid ground. For the full version, the site's glossary goes further.

Around form and preparation

• Lyophilizate: the dry powder obtained by lyophilization (freeze-drying). This is the state in which a peptide is stable and transported.
• Reconstitution: the operation that redissolves the lyophilizate in a solvent to obtain a solution of known concentration. See the reconstitution guide.
• Bacteriostatic water (BAC): sterile water + 0.9% benzyl alcohol, which slows bacterial growth and allows draws over time.

Around concentration and measurement

• Concentration: amount of peptide per unit of volume, in mg/ml or mcg/ml. It is calculated by dividing the peptide mass by the volume of water added.
• mcg: microgram, i.e. one thousandth of a milligram (1 mg = 1000 mcg).
• Syringe units (IU): graduations on an insulin syringe. In the U-100 system, 1 IU = 0.01 ml. Detailed in Reading your syringe.

Around the molecule's behavior

• Half-life: the time after which half of an amount has been eliminated or degraded. It indicates how persistent a peptide is.
• Bioavailability: the fraction actually available after administration, depending on the route used.
• Titration: starting with a small amount then increasing gradually, in stable steps, to assess tolerance in a research setting.

Around quality

• COA (certificate of analysis): a document attesting the identity and purity of a specific batch (HPLC + mass spectrometry). See Understanding the COA.
• Purity: the proportion of the content that corresponds to the target peptide, expressed as a percentage.
• Blend: a mixture of several peptides packaged together.

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This lexicon covers the essentials for reading a product sheet or a COA without getting lost. To explore molecule by molecule, the product sheets gather the chemical identity, sources and reference points of each peptide.