How much water do I add to a 20 mg Cortagen vial?

There is no single correct amount: water changes how many units a dose is, not how many doses the vial holds. With 1 mL the vial is 20 mg/mL and 5 mg is 25 units (0.25 mL) on a U-100 insulin syringe. The units table gives 1, 2, 3 mL.

How many doses are in a 20 mg Cortagen vial?

100 doses at 200 mcg, 4 doses at 5 mg, 2 doses at 10 mg.

How long does a 20 mg Cortagen vial last?

At 5 mg a dose and once daily, about 0.6 weeks. How long a mixed vial keeps is a separate limit; see storage below.

How many 20 mg vials do I need for a cycle?

1 vial at 200 mcg 7 times a week for 1.4 weeks; 11 vials at 10 mg 7 times a week for 2.9 weeks.

What does 1 unit equal in a 20 mg Cortagen vial?

200 mcg with 1 mL, 100 mcg with 2 mL, 66.67 mcg with 3 mL of bacteriostatic water, on a U-100 syringe.

Research use only · common protocol

Cortagen 20 mg vial dosage

A 20 mg Cortagen vial mixed with 1 mL of bacteriostatic water gives 20 mg/mL, so 5 mg is 25 units (0.25 mL) on a U-100 insulin syringe. At 5 mg a dose, one vial holds 4 doses.

Email me this plan, with a reminder before the vial's 28-day mark →

The common Cortagen protocol is 200-10000 mcg, once daily, subcutaneous, ideally in the morning; sources give very different amounts depending on intended use - common practice, not a dose established in trials. Evidence, side effects and legal status are on the Cortagen guide.

Cortagen 20 mg vial at a glance

Vial: 20 mg of Cortagen per vial
Common dose: 200-10000 mcg
How often: once daily, subcutaneous, ideally in the morning; sources give very different amounts depending on intended use
Mixing example: 1 mL bacteriostatic water = 20 mg/mL; 1 unit = 200 mcg
Doses per vial: 100 at 200 mcg · 4 at 5 mg · 2 at 10 mg
Cycle: 1.4-2.9 weeks, then 13-26 weeks off

What Cortagen is

Class:: Synthetic tetrapeptide (Ala-Glu-Asp-Pro)
Also called:: AEDP, AEDP peptide, Ala-Glu-Asp-Pro
Used for:: Marketed as a brain-cortex bioregulator for cognitive aging, from the Khavinson organ-specific peptide programme. Its sequence was derived by amino-acid analysis of the natural brain-cortex extract preparation Cortexin.
Human evidence:: Animal / lab only. Every study of Cortagen I located and read is an animal experiment - a gene-expression microarray in mouse heart tissue and a behavioural/biochemical study in ischemic rat brains - from Russian research groups working in the same peptide-bioregulator tradition. One of the papers I read states, as background rather than as its own finding, that Cortagen showed a therapeutic effect on human peripheral-nerve recovery after injury; I could not independently locate and verify that human claim as a primary trial.
US status:: Research use only. Not approved for human use by the FDA or any other regulator, and sold as a research chemical.

The full picture, with every study: Cortagen guide.

Units per dose: Cortagen 20 mg vial

Water added	Concentration	1 unit =	200 mcg	5 mg	10 mg
1 mL	20 mg/mL	200 mcg	1 unit	25 units	50 units
2 mL	10 mg/mL	100 mcg	2 units	50 units	100 units
3 mL	6.67 mg/mL	66.67 mcg	3 units	75 units	over 100 units

U-100 insulin syringe (100 units = 1 mL), to the nearest half unit. Water volumes are examples. Other numbers: dosage calculator.

Every dose from 200 mcg to 10 mg, in units

With 1 mL of water in a 20 mg vial (20 mg/mL). Every dose across the common range, so you can read off any dose. The sources give a range, not a week-by-week schedule.

Dose	Draw on a U-100 syringe	Volume	Doses per vial
200 mcg	1 unit	0.01 mL	100
2 mg	10 units	0.1 mL	10
4 mg	20 units	0.2 mL	5
6 mg	30 units	0.3 mL	3
8 mg	40 units	0.4 mL	2
10 mg	50 units	0.5 mL	2

How many doses a 20 mg vial holds

Dose	Doses per vial	Weeks per vial
200 mcg	100	14.3
5 mg	4	0.6
10 mg	2	0.3

Weeks per vial at the common frequency (once daily, subcutaneous, ideally in the morning; sources give very different amounts depending on intended use). Doses per vial do not depend on how much water you add.

Email me my Cortagen 20 mg vial plan

Pick your water volume and dose and I will email you the numbers for this vial - units, volume, doses per vial and how long it lasts - plus the mixing and storage steps, and a reminder before the mixed vial reaches 28 days.

The common Cortagen protocol

Dose	200-10000 mcg per injection
How often	once daily, subcutaneous, ideally in the morning; sources give very different amounts depending on intended use
Route	Subcutaneous injection
Cycle	1.4-2.9 weeks
Break	13-26 weeks
Sources agree?	Partly - the sources differ, and the ranges above cover them

Common practice from the vendors and clinics that publish it, not a dose tested in trials. Where it comes from: [1], [2]. I do not give week-by-week titration: none of these sources states one.

Supplies for one cycle with 20 mg vials

Counted for the low and high ends of the common protocol, mixing each vial with 1 mL of water. One new syringe per injection.

Plan	Injections	20 mg vials	Insulin syringes	Bacteriostatic water	Alcohol swabs
200 mcg, 7×/week, 1.4 weeks	10	1	10	1 mL (1 × 10 mL bottle)	22 (1 × 100-pack)
10 mg, 7×/week, 2.9 weeks	21	11	21	11 mL (2 × 10 mL bottles)	64 (1 × 100-pack)

Arithmetic on the protocol and this vial size. Swabs: two per vial mixed (both stoppers) and two per injection (vial stopper and skin). An opened multi-dose vial has a use-by date (see storage), which on a slow schedule can matter more than the dose count. Plan your own numbers with the protocol builder.

How to mix a 20 mg Cortagen vial

For this vial: 1 mL of bacteriostatic water makes 20 mg/mL, so 5 mg is 25 units (0.25 mL) on a U-100 insulin syringe. Pick a different volume from the units table if you want bigger or smaller draws; the number of doses stays the same.

Wipe the rubber stoppers of both the peptide vial and the bacteriostatic water vial with an alcohol swab and let the alcohol dry. ^[3][4]
With a new sterile needle and syringe, draw up the amount of bacteriostatic water you have chosen for the dilution. ^[3][4][5]
Inject the water into the peptide vial by aiming the stream against the inside glass wall, which helps prevent foaming. ^[6]
Swirl or roll the vial gently until the powder has fully dissolved; do not shake it. Do not inject the solution if it is cloudy or has particles in it. ^[3][4][6]
Label the vial with the date and time it was mixed, the amount of water added and how long it can be used after mixing. ^[3]
Store the mixed vial in the refrigerator at 2-8°C (36-46°F) and do not freeze it. ^[6]

Step by step with pictures: how to reconstitute peptides. About the water itself: bacteriostatic water.

Storing Cortagen vials

Freeze-dried (lyophilized) peptide keeps far longer than peptide in solution; peptide suppliers advise storing the powder at -20°C away from bright light. ^[7]
Protect peptide vials from heat and light. ^[7][8]
Avoid repeated freeze-thaw cycles; a prescription peptide label also says not to freeze a vial once it has been mixed. ^[6][7]
Once a multi-dose vial, such as bacteriostatic water, has been opened (needle-punctured), date it and discard it within 28 days unless its manufacturer states another date. ^[9][10]

More detail: peptide storage and shelf life.

Injecting safely

Clean the injection site with an alcohol swab and let the skin dry completely before injecting. ^[11][12]
Pinch up a fold of skin and fat (not muscle) and insert the needle at a 45- to 90-degree angle: 90 degrees where there is enough fatty tissue, 45 degrees where there is little. ^[11][12][13]
Pulling back on the plunger (aspiration) is not necessary for a subcutaneous injection, because the chance of the needle being in a blood vessel is small. ^[11]
Inject slowly, at roughly 10 seconds per mL. ^[11]
Common sites are the belly, the thigh and the upper arm; rotate sites, keeping each injection at least 1 inch (2.5 cm) from the last. ^[6][11][12]

Hygiene and warning signs

Use a new sterile needle and syringe for every injection and every time you enter a vial; never reuse them. ^[5][9][12]
Never share needles, syringes or pens with anyone, even if the needle is changed; unsafe injection practices spread hepatitis B, hepatitis C and HIV. ^[5][8][9]
Put used needles and syringes in a sharps disposal container straight away (FDA-cleared if possible), never loose in the trash, recycling or toilet, and dispose of the container following your community's guidelines. ^[14][15]
Contact a health care provider if the injection site shows signs of infection, such as redness, swelling, red streaks or a fever. ^[12]

Where to inject: subcutaneous injection sites.

How Cortagen works

Cortagen is a synthetic tetrapeptide, Ala-Glu-Asp-Pro. It was designed from an amino-acid analysis of Cortexin, a peptide preparation from brain cortex. ^[16]
Its developers describe it as tissue-specific: in organotypic cultures of rat tissue, Cortagen stimulated the growth of brain-cortex explants, the tissue whose peptide complex it was modelled on. ^[17]
The proposed mode of action is a change in gene activity. After five days of Cortagen injections in mice, 234 of 15,247 transcripts measured in the heart (matching 110 known genes) showed significant changes in expression. ^[16]
In white blood cells taken from people aged 75-88, Cortagen and four related short peptides activated ribosomal genes and loosened tightly packed chromatin, which the authors read as releasing genes switched off with age. ^[18]

What the Cortagen research found

Human evidence: animal / lab only. Each result says what was studied.

Animal studyIn rats whose sciatic nerve had been cut and sutured, 10 days of intramuscular Cortagen at 10 micrograms per kg increased the growth rate of the regenerating nerve fibres by 27% and their conduction velocity by 40%. ^[19]
Animal studyIn rats with chronic brain ischaemia, Cortagen and the extract Cortexin both sped recovery of disturbed behaviour and prevented excess lipid peroxidation and a fall in antioxidant activity in brain tissue. ^[20]
Animal studyThe mouse heart microarray study compared Cortagen with Vilon, Epitalon and melatonin and found some gene-expression changes shared with those compounds and some specific to Cortagen. ^[16]
Animal studyA null result: in chickens that had the pituitary removed shortly after hatching, and in old birds given the same operation, 40 days of Epitalon injections fully reversed changes in red blood cells, immunity and blood clotting, but Cortagen injections did not affect any of these measures. ^[21]
Lab studyAnother null result: in mouse thymus cells, Vilon and Epitalon boosted proliferation alongside a mitogen, but Cortagen produced no such effect. ^[22]

Cortagen side effects and risks

I found no published human safety data for Cortagen, and the abstracts of the animal and cell studies I read do not report adverse effects.

No human trial of Cortagen that I could independently verify has been published. A background claim of human peripheral-nerve benefit appears in one paper's introduction, citing other work I could not locate and check myself.
A separate, related peptide, Cortexin, is a different, less chemically defined bovine/porcine brain-cortex extract with its own clinical use in some countries; Cortagen is the later, synthetic, single-sequence tetrapeptide covered here, and evidence for one does not automatically transfer to the other.
Nearly all published research on this molecule comes from a small number of Russian research groups, much of it in Russian, and has not been independently replicated more broadly.
Sold through unregulated research-chemical channels, so nobody outside the vendor verifies what is actually in a given vial.

Reported side effects and what the studies measured: Cortagen side effects.

Where this vial size comes from

Cortagen is sold as a 20 mg vial by the pages below, each checked on the date shown. I list them as evidence that this size exists, not as a recommendation to buy from them.

Next Level PharmvendorLists it as: "Cortagen (20mg)"; size option 20mg · checked 2026-09-28
BioEdge Research LabsvendorLists it as: "Cortagen (20mg)"; Fill: 20mg · checked 2026-09-28

The doses come from the sourced common protocol on the Cortagen guide, and every number on this page is arithmetic on those doses and this vial size.

Other Cortagen vial sizes

10 mg vial
20 mg

Where to buy Cortagen for research

Sold for research use only. Listed by Next Level Pharm and BioEdge Research Labs; compare them on my vendors page or see the listing on the Cortagen page.

Questions

How much water do I add to a 20 mg Cortagen vial?: There is no single correct amount: water changes how many units a dose is, not how many doses the vial holds. With 1 mL the vial is 20 mg/mL and 5 mg is 25 units (0.25 mL) on a U-100 insulin syringe. The units table gives 1, 2, 3 mL.
How many doses are in a 20 mg Cortagen vial?: 100 doses at 200 mcg, 4 doses at 5 mg, 2 doses at 10 mg.
How long does a 20 mg Cortagen vial last?: At 5 mg a dose and once daily, about 0.6 weeks. How long a mixed vial keeps is a separate limit; see storage below.
How many 20 mg vials do I need for a cycle?: 1 vial at 200 mcg 7 times a week for 1.4 weeks; 11 vials at 10 mg 7 times a week for 2.9 weeks.
What does 1 unit equal in a 20 mg Cortagen vial?: 200 mcg with 1 mL, 100 mcg with 2 mL, 66.67 mcg with 3 mL of bacteriostatic water, on a U-100 syringe.

References (22 sources)

[1] Path To Peptides: 200 mcg SC daily, 7 days/week, 10-day cycle, 10mg vial in 2mL BAC water (5mg/mL), 28 units (1400mcg) per week, ~50-day vial duration (other, checked 2026-09-28)
[2] PeptideWiki: 1-10 mg SC daily (1-3mg nootropic tier, 5-10mg neurological-support tier), morning administration preferred, 10-20 day cycles, 3-6 month break, 5-10mg vials, oral capsule alternative also described (other, checked 2026-09-28)
[3] OpenStax, Rice University: 12.3 Preparing Unit-Dose Packaged Medications - Clinical Nursing Skills
[4] East Carolina University College of Nursing: Reconstitution of Medication
[5] Centers for Disease Control and Prevention: Considerations for Blood Glucose Monitoring and Insulin Administration
[6] DailyMed, National Library of Medicine: SEROSTIM (somatropin) for injection - prescribing information and instructions for use
[7] GenScript: Peptide Storage and Handling Guidelines
[8] DailyMed, National Library of Medicine: OZEMPIC (semaglutide) injection - prescribing information
[9] Centers for Disease Control and Prevention: Preventing Unsafe Injection Practices
[10] Pfizer: Bacteriostatic Water for Injection, USP - prescribing information
[11] OpenStax, Rice University: 12.5 Administering Subcutaneous Injections - Clinical Nursing Skills
[12] MedlinePlus, National Library of Medicine: Subcutaneous (SQ) injections
[13] Centers for Disease Control and Prevention: Chapter 6: Vaccine Administration - Pink Book
[14] US Food and Drug Administration: Best Way to Get Rid of Used Needles and Other Sharps
[15] US Food and Drug Administration: DOs and DON'Ts of Proper Sharps Disposal
[16] Anisimov SV, Khavinson VKh, Anisimov VN. Elucidation of the effect of brain cortex tetrapeptide Cortagen on gene expression in mouse heart by microarray. Neuro Endocrinol Lett. 2004;25(1-2):87-93.
[17] Khavinson VK. Tissue-specific effects of peptides. Bull Exp Biol Med. 2001;132(2):807-8.
[18] Khavinson VKh, Lezhava TA, Malinin VV. Effects of short peptides on lymphocyte chromatin in senile subjects. Bull Exp Biol Med. 2004;137(1):78-81.
[19] Turchaninova LN, Kolosova LI, Malinin VV et al. Effect of tetrapeptide cortagen on regeneration of sciatic nerve. Bull Exp Biol Med. 2000;130(12):1172-4.
[20] Zarubina IV, Shabanov PD. [Cortexin and cortagen as correcting agents in functional and metabolic disorders in the brain in chronic ischemia]. Eksp Klin Farmakol. 2011;74(2):8-15.
[21] Kuznik BI, Pateiuk AV, Baranchugova LM et al. [Effects of epithalon and cortagene on immunity and hemostasis in neonatally hypophysectomized chicken and old birds]. Adv Gerontol. 2008;21(3):372-81.
[22] Khavinson VKh, Rybakina EG, Malinin VV et al. Effects of short peptides on thymocyte blast transformation and signal transduction along the sphingomyelin pathway. Bull Exp Biol Med. 2002;133(5):497-9.