Peptide Glossary

The building blocks of peptides and proteins. There are 20 standard amino acids that combine in various sequences to form peptides. Each amino acid has a unique side chain that determines its properties.

Relating to the metabolic process of building complex molecules from simpler ones, typically associated with muscle growth and tissue repair. Many peptides have anabolic properties.

Sterile water containing 0.9% benzyl alcohol as a preservative. Used to reconstitute peptides, it inhibits bacterial growth and extends the shelf life of reconstituted solutions to approximately 28 days.

The proportion of a substance that enters the circulation and is able to have an active effect. Subcutaneous injection typically provides higher bioavailability than oral administration for peptides.

A protein that supports neuron survival and encourages growth of new neurons and synapses. Several nootropic peptides (Semax, Selank) increase BDNF expression.

Relating to the metabolic process of breaking down complex molecules into simpler ones, often releasing energy. Cortisol is a catabolic hormone.

A steroid hormone released in response to stress. Some GHRPs can increase cortisol levels, which is why selective peptides like Ipamorelin are often preferred.

A modification added to peptides (like CJC-1295 DAC) that binds to albumin in the blood, dramatically extending half-life from minutes to days.

A reduction in receptor response after prolonged or repeated exposure to a stimulus. Some GHRPs may cause receptor desensitization with continuous use, which is why cycling is sometimes recommended.

A liquid used to dissolve or dilute a substance. For peptides, common diluents include bacteriostatic water and sterile water.

A peptide hormone produced by the pituitary gland that stimulates growth, cell reproduction, and regeneration. GH secretagogues stimulate natural GH release.

A hormone produced by the hypothalamus that stimulates the pituitary to release growth hormone. GHRH analogs like CJC-1295 and Sermorelin mimic this action.

A class of synthetic peptides that stimulate GH release by activating the ghrelin receptor. Examples include Ipamorelin, GHRP-6, GHRP-2, and Hexarelin.

The "hunger hormone" produced mainly in the stomach. It stimulates appetite and GH release. GHRPs work by mimicking ghrelin's action on the ghrelin receptor.

An incretin hormone that stimulates insulin secretion. Tirzepatide and Retatrutide are dual/triple agonists that activate both GIP and GLP-1 receptors.

An incretin hormone that stimulates insulin secretion, inhibits glucagon, slows gastric emptying, and promotes satiety. GLP-1 agonists like Semaglutide are used for diabetes and weight management.

The time required for the concentration of a substance to decrease by half. Peptide half-lives range from minutes (Sermorelin) to days (CJC-1295 DAC, Semaglutide).

A growth factor involved in cell growth, motility, and tissue regeneration. Dihexa works by activating the HGF/c-Met pathway.

A hormone similar in structure to insulin that mediates many of growth hormone's effects. GH stimulates the liver to produce IGF-1.

A group of metabolic hormones that stimulate insulin secretion in response to meals. GLP-1 and GIP are the main incretins.

An injection route where the substance is delivered directly into muscle tissue. Less common for peptides than subcutaneous injection.

Administration through the nasal passages. Some peptides like Semax and Selank are commonly administered intranasally for direct access to the brain.

Abnormal distribution of fat tissue, which can occur at injection sites with repeated use. Rotating injection sites helps prevent this condition.

An initial period of higher or more frequent dosing to quickly achieve therapeutic levels. Common with TB-500 protocols.

The freeze-drying process used to preserve peptides. Lyophilized peptides are more stable and have longer shelf lives than liquid formulations.

The period following a loading phase where dosing is reduced to maintain therapeutic levels. Often involves less frequent administration.

A unit of mass equal to one millionth of a gram (0.001mg). Many peptide doses are measured in micrograms.

A unit of mass equal to one thousandth of a gram. Peptide vial sizes are typically measured in milligrams (e.g., 5mg, 10mg).

The brain's ability to form new neural connections and reorganize itself. Nootropic peptides like Semax and Dihexa may enhance neuroplasticity.

A protein that promotes the survival and development of nerve cells. Some peptides like Semax can increase NGF expression.

A substance that enhances cognitive function, including memory, creativity, and motivation. Peptides like Semax, Selank, and Dihexa have nootropic properties.

A short chain of amino acids (typically 2-50) linked by peptide bonds. Peptides are smaller than proteins and often have specific biological functions.

A small gland at the base of the brain that produces and releases hormones including growth hormone. GH secretagogues stimulate the pituitary to release GH.

A hormone primarily associated with lactation. Some GHRPs can increase prolactin levels, which is why selective peptides are often preferred.

A large, complex molecule made up of one or more chains of amino acids. Proteins are larger than peptides (typically 50+ amino acids).

The natural pattern of hormone secretion in bursts or pulses rather than continuously. GHRPs promote pulsatile GH release, mimicking natural physiology.

A protein on or in a cell that binds to specific molecules (ligands) and triggers a cellular response. Peptides work by binding to specific receptors.

A substance that binds to a receptor and activates it, producing a biological response. GLP-1 agonists activate GLP-1 receptors.

The process of adding a diluent (usually bacteriostatic water) to a lyophilized peptide powder to create an injectable solution.

The feeling of fullness and satisfaction after eating. GLP-1 agonists promote satiety, which helps reduce food intake.

A substance that promotes secretion. GH secretagogues stimulate the release of growth hormone from the pituitary gland.

The specific order of amino acids in a peptide chain. The sequence determines the peptide's structure and function.

Water that has been purified and sterilized but contains no preservatives. Can be used for reconstitution but the solution should be used within 24-48 hours.

An injection route where the substance is delivered into the fatty tissue just beneath the skin. The most common administration route for peptides.

The formation of new synapses (connections between neurons). Peptides like Dihexa promote synaptogenesis, potentially enhancing cognitive function.

The process of gradually adjusting a dose to find the optimal amount. GLP-1 agonists are typically titrated upward over several weeks to minimize side effects.

An insulin syringe calibrated for 100 units per milliliter. The standard syringe type for peptide administration, where 100 units = 1mL.

A small container, typically glass, that holds lyophilized peptide powder. Vials have rubber stoppers that allow needle access while maintaining sterility.