Testagen: what it is, what the studies show and where it stands
Testagen is a synthetic tetrapeptide, Lys-Glu-Asp-Gly (KEDG). The researchers who made it say it was built from the amino acid composition of peptide extracts of the pituitary gland.
At a glance
US Not approved
Canada Not authorized
Group Hormonal and sexual health
Sources 11
Checked 10 Oct 2026What is Testagen?
Testagen is a synthetic tetrapeptide, Lys-Glu-Asp-Gly (KEDG). The researchers who made it say it was built from the amino acid composition of peptide extracts of the pituitary gland. [1]
Other names: KEDG, Lys-Glu-Asp-Gly.
How it has been given to people: no human use on record.
Looking for doses? Testagen dosage chart and vial math
Is Testagen approved in the US and Canada?
United States: Not FDA approved. No Testagen peptide product is in Drugs@FDA, and it is not on the FDA page of bulk substances reviewed for compounding. [7]
Canada: No Testagen product is in the Health Canada Drug Product Database. Health Canada warns against all unauthorized injectable peptide drugs. [9]
Both were checked on 10 Oct 2026 against the regulators' own product databases.
Which approved products contain Testagen?
No approved medicine containing Testagen was found in the US or Canada. Anything sold under this name is not a regulated product, so there is no label to check a dose against.
What human studies of Testagen exist?
The 4 findings listed here: 4 from animal or lab work.
In chickens whose pituitary gland was removed, 40 days of Lys-Glu-Asp-Gly or Ala-Glu-Asp-Gly was followed by higher thyroid-stimulating hormone and thyroid hormone levels and recovery of thyroid structure. The abstract gives no dose. [2]
In a follow-up in young chickens and old hens, the effect on thyroid hormones was weaker in the old birds. [3]
In birds whose pituitary gland was removed, the peptide helped the structure of the thymus recover, more so than Ala-Glu-Asp-Gly did. [4]
A fluorescent-tagged version entered human HeLa cells in culture and reached the nucleus, and the plain peptide bound DNA fragments in a test tube with a preference for certain sequences. [1]
What are the side effects of Testagen?
Reported in human studies or on a label:
- No human side-effect report for Testagen was found. Health Canada lists these risks for unauthorized injectable peptide drugs in general: hormonal imbalance, mood swings, blood sugar imbalance, liver or kidney damage, blood clots and growth of cancerous tumours. [9]
How does Testagen compare with others in its group?
These are the peptides filed under hormonal and sexual health. The last column says whether a randomized human trial is on record for each.
| Peptide | US | Canada | Half-life | Randomized human trial |
|---|---|---|---|---|
| PT-141 (bremelanotide) | Approved for one use | Not authorized | About 2.7 hours after a single subcutaneous dose (the label gives a range of 1.9 to 4.0 hours). Blood levels peak at about 1 hour. | Yes |
| Kisspeptin-10 | Not approved | Not authorized | Not found | Yes |
| Gonadorelin | No longer sold | No longer sold | Very short. After intravenous or subcutaneous injection, blood levels fall with an initial half-life of 2 to 10 minutes and a terminal half-life of 10 to 40 minutes. | No |
| Testagen | Not approved | Not authorized | Not found | No |
| HCG | Approved, prescription | Authorized, prescription | About 32 to 33 hours after a single injection of 5,000 or 10,000 IU in 18 healthy women, the same by muscle or under the skin. | Yes |
| HMG | Approved, prescription | Authorized, prescription | FSH from Menopur had an elimination half-life of 11 to 13 hours after repeated doses, by injection under the skin or into a muscle. The label gives no half-life for the LH part. | Yes |
What could not be found
These were searched for and did not turn up. They are listed so a missing number is not mistaken for a hidden one.
- No published human study of Testagen of any kind. PubMed lists two records under the name (a cell and DNA binding study and a copper corrosion paper) and a handful under the sequence Lys-Glu-Asp-Gly, all in birds.
- No study measuring testosterone, luteinizing hormone, sperm or any other male reproductive outcome, in people or in animals. The bird studies measured thyroid hormones and thymus structure.
- No dose in any abstract read, human or animal.
- No human half-life or other pharmacokinetic figure.
- No trial of the peptide on ClinicalTrials.gov. The one result for testagen is a testosterone skin spray with the same name [11].
- No approved label in the US or Canadian sources searched, so no official dose, contraindications, interaction list or storage instructions.
- No human side-effect or safety data.
Testagen questions
Is Testagen approved in the US?
Not FDA approved. No Testagen peptide product is in Drugs@FDA, and it is not on the FDA page of bulk substances reviewed for compounding.
Is Testagen authorized in Canada?
No Testagen product is in the Health Canada Drug Product Database. Health Canada warns against all unauthorized injectable peptide drugs.
Has Testagen been tested in a randomized human trial?
No randomized human trial was found. What exists is listed under the studies heading on this page.
Sources
Each one was opened on 10 Oct 2026 and matched to the line it supports.
- Fedoreyeva LI et al. Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry (Mosc) 2011. PubMed 22117547.
- Kuznik BI et al. Effect of tetrapeptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the structure and function of the thyroid gland in neonatally hypophysectomized chickens. Bull Exp Biol Med 2008. PubMed 19024016.
- Kuznik BI et al. Effects of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on hormonal activity and structure of the thyroid gland in hypophysectomized young chickens and old hens. Bull Exp Biol Med 2011. PubMed 22268052.
- Pateyk AV et al. Effect of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the morphology of the thymus in hypophysectomized young and old birds. Bull Exp Biol Med 2013. PubMed 23658898.
- Dobritescu A et al. The Inhibitory Effect and Adsorption Properties of Testagen Peptide on Copper Surfaces in Saline Environments: An Experimental and Computational Study. Molecules 2025. PubMed 40807317.
- Khavinson V et al. Transport of Biologically Active Ultrashort Peptides Using POT and LAT Carriers. Int J Mol Sci 2022. PubMed 35887081.
- US Food and Drug Administration openFDA search of Drugs@FDA: testagen 2026. api.fda.gov.
- US Food and Drug Administration Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks 2026. fda.gov.
- Health Canada Think twice before injecting peptides bought online: unauthorized products can seriously harm you 2026. recalls-rappels.canada.ca.
- Health Canada Health Canada Drug Product Database, active ingredient search: testagen 2026. health-products.canada.ca.
- ClinicalTrials.gov Product Transference Study of Testagen TDS-Testosterone 2026. clinicaltrials.gov. Trial NCT02733133.
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Testagen dosage20 mg vialHormonal and sexual healthStatus in Canada
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