Cortagen: Reference Overview and Reconstitution Notes

Cortagen is a lab-made brain-cortex tetrapeptide (a tiny molecule built from four amino acid building blocks) in the Khavinson bioregulator family. It is studied in neural and anti-aging research and is not FDA-approved (research use only).

What it is

Cortagen is a synthetic (lab-made) short-chain peptide. A peptide is a small molecule made of amino acids, which are the building blocks proteins are made from. Cortagen is a tetrapeptide, meaning it is built from exactly four of these building blocks. Those four are Alanine, Glutamic acid, Aspartic acid, and Proline (often written as Ala-Glu-Asp-Pro or AEDP).

It belongs to the Khavinson family of peptide bioregulators. Bioregulators are short peptides that researchers study for their possible effects on how specific tissues function. This family was developed by studying peptide preparations taken from particular body tissues. In Cortagen's case, that source tissue is a brain-cortex preparation called cortexin.

Key point: Cortagen is an unapproved, research-only synthetic tetrapeptide (AEDP) belonging to the Khavinson bioregulator family.

Research context and categorization

Cortagen is generally categorized as a neural or brain-cortex bioregulator within Khavinson bioregulator and anti-aging peptide research. It was developed by Professor Vladimir Khavinson and colleagues at the St. Petersburg Institute of Bioregulation and Gerontology.

Investigational Studies

In research terms, Cortagen is often discussed alongside the "bioregulator hypothesis." This is the idea that very short peptides may be able to affect gene expression (the process by which genes in a cell are switched on or off) in particular tissue types. Think of it like a small key that might fit a specific lock found only in certain cells.

It has been studied in laboratory and animal models for topics such as peripheral nerve regeneration (the regrowth of nerves that run outside the brain and spinal cord) after injury, how neural tissue responds to reduced blood flow, and shifts in gene-activity patterns linked to cortical tissue and aging. One published microarray study (a lab test that checks the activity of many genes at once) looked at how the peptide affected gene expression in animal tissue.

Regulatory Status

These areas of study are investigational and are carried out in research settings. Cortagen is not FDA-approved, and none of the effects discussed above are confirmed or approved outcomes in humans. They represent areas of ongoing study, not proven benefits.

Status

• Regulatory status: Research-only. Cortagen is not FDA-approved for any use and is handled as a research compound.
• Sport status: Cortagen is not specifically named on the WADA (World Anti-Doping Agency) Prohibited List. However, WADA includes a catch-all category called S0 that covers any substance not currently approved by a government health authority for human therapeutic use. Because Cortagen is an unapproved experimental peptide, that provision may apply. Anyone subject to anti-doping rules should confirm the current status directly with WADA or their governing body.

Reconstitution notes (general)

Reconstitution means dissolving a freeze-dried powder in water to make a liquid solution. For lyophilized (freeze-dried) peptides supplied as a powder, you calculate the concentration by dividing the milligrams of peptide in the vial by the millilitres of bacteriostatic water (water with a small preservative added to slow bacterial growth) you add.

For example, a 20 mg vial mixed with 3 mL of bacteriostatic water gives a concentration of roughly 6.67 mg/mL.

To work out a target concentration or fill volume for any vial size, use the calculator at peptide calculator.

Dilution and handling notes (compound-specific)

Solubility and Appearance

Cortagen is typically supplied as a lyophilized (freeze-dried) powder in vial sizes such as 10 mg, 20 mg, or 50 mg, intended to be reconstituted with bacteriostatic water.

Because Cortagen is a very small tetrapeptide with no cysteine residues and no disulfide bonds (the molecular "clips" that hold some larger proteins in shape), it dissolves easily. It does not tend to gel, turn cloudy, or form solid bits the way some larger or water-repelling peptides do. The result is a clear, colorless liquid.

Typical reconstitution volumes reported across suppliers fall in the low single-digit millilitre range, for example around 2 mL to 3 mL per 20 mg vial (giving roughly 10 mg/mL down to about 6.67 mg/mL). The volume you choose depends mainly on how precisely you need to measure on a marked syringe, not on any solubility limit.

Handling Best Practices

The handling steps are the standard ones for small freeze-dried peptides. Add the liquid slowly, aiming the stream at the inner glass wall rather than directly onto the powder. Then let the vial sit and swirl it gently instead of shaking it.

Vigorous shaking creates foam and makes the fill level hard to read. Gentle swirling until the solution clears is the standard approach.

If the material does not fully clear, or if solid bits remain after swirling, set the vial aside rather than trying to force it. Avoid repeatedly freezing and thawing a vial once it has been mixed into a solution.

Handling and storage

• Store reconstituted vials in a refrigerator at 2 to 8 degrees Celsius and keep them away from direct light.
• Wipe the rubber stopper with an alcohol swab before each puncture.
• Write the mix date on the vial so the age of the solution is always known.
• Follow the general working window of about four weeks under refrigeration for a reconstituted vial.
• Discard anything that turns cloudy or discolored, or that develops visible floating bits or particles.

Related reading

• Crystagen
• Dermorphin
• DSIP (Delta Sleep-Inducing Peptide)
• How Reconstitution Works
• How Long Does a Reconstituted Vial Last?

Tools and supplies

• peptide calculator
• Bacteriostatic Water 30 ml
• Gansulin Metal Reusable Pen
• 3 ml Glass Cartridges (10-pack)
• Complete Starter Kit

Reminder: research and educational reference only. Preppin Peppers sells hardware and materials, not peptides. Not medical, dosing, or health advice, not evaluated by the FDA, and not intended for human or animal use.

Frequently asked questions

What is Cortagen and what is its amino acid sequence?

Cortagen is a synthetic tetrapeptide with the sequence Ala-Glu-Asp-Pro (AEDP), derived from cortexin-based research. It belongs to the Khavinson bioregulator family and is investigated as a neural/brain-cortex research compound.

Is Cortagen FDA-approved or prohibited under WADA anti-doping rules?

Cortagen is not FDA-approved and is classified as research-only. It is not specifically named on the WADA Prohibited List, but the catch-all S0 category may apply because it is an unapproved experimental peptide. Confirm status with WADA directly.

How do you calculate peptide concentration when reconstituting a lyophilized vial?

Divide the milligrams of peptide in the vial by the volume of bacteriostatic water added in milliliters. The result is the concentration in mg/mL. This arithmetic applies to any lyophilized research peptide reconstituted in aqueous solvent.

What the research community gets wrong about Cortagen

• Treating Cortagen and Cortexin as the same thing. Cortexin is a natural extract taken from brain-cortex tissue and is a mixture of many components. Cortagen is a single, defined synthetic tetrapeptide (Ala-Glu-Asp-Pro) made to a set sequence. At the bench these are different materials with different contents, so notes or handling steps written for one vial do not automatically carry over to the other.
• Mixing up the sequence with Epitalon. Cortagen is AEDP (Ala-Glu-Asp-Pro). Epitalon is AEDG (Ala-Glu-Asp-Gly). The abbreviations look almost identical and some labels swap them. Read the exact three-letter sequence on the certificate of analysis rather than trusting a four-letter code alone.
• Assuming a small peptide needs heavy solvent tricks. Because Cortagen is short and has no cysteine residues or disulfide bonds, it tends to dissolve into a clear, colorless liquid with plain gentle swirling. Warming, sonication, or acidic solvents are not the expected step for a vial like this, and reaching for them first can add variables you did not need.
• Reading published results as more than an early animal signal. The peer-reviewed work is a small set of studies, largely from the group that developed the peptide, run in rat and mouse models. Those reports describe measurements in animal tissue, not confirmed outcomes, and have not been widely reproduced by independent labs. Keep any summary framed as what was measured in a study, not as an established effect.
• Thinking a reported molecular weight is a single fixed number. Values listed by different vendors for Cortagen do not always agree, partly because a peptide can be quoted as a free acid, a salt, or with different assumptions. When a calculation depends on it, check the molecular weight against the stated formula and sequence instead of copying a number from a product page.

From our bench: If you have reconstituted a Cortagen vial, we would like your firsthand handling notes. Tell us the vial size (mg), the exact volume of bacteriostatic water you added (mL), and how long the powder took to go fully clear with gentle swirling. Note whether the finished liquid stayed clear and colorless or showed any haze or floating bits, and at what point you observed it. Please share only your own measured, observed numbers, not figures copied from a label.

Sources

1. Bacteriostatic Water for Injection, USP , FDA/DailyMed label (0.9% benzyl alcohol)
2. Duerkop et al., Biotechnol J 2018 , Impact of Cavitation, High Shear Stress and Air/Liquid Interfaces on Protein Aggregation
3. Sigma-Aldrich (Merck) , Handling and Storage Guidelines for Peptides and Proteins
4. PubChem CID 18439621: Cortagen (Ala-Glu-Asp-Pro), molecular formula C17H26N4O9
5. Turchaninova et al., Bull Exp Biol Med 2000: Effect of tetrapeptide cortagen on regeneration of sciatic nerve (PMID 11276314)
6. Anisimov, Khavinson & Anisimov, Neuro Endocrinol Lett 2004: Effect of brain cortex tetrapeptide Cortagen on gene expression in mouse heart by microarray (PMID 15159690)