Testagen
Also known as: Testes peptide bioregulator · LKEK tetrapeptide · Male gonadal bioregulator
A tetrapeptide (Lys-Glu-Asp-Glu estimated) testes-targeting bioregulator from the Khavinson series. Normalizes Leydig cell function, testosterone synthesis, and testicular morphology. Used in male reproductive aging, hypogonadism research, and testosterone support protocols.
What is Testagen? A tetrapeptide (Lys-Glu-Asp-Glu estimated) testes-targeting bioregulator from the Khavinson series. Normalizes Leydig cell function, testosterone synthesis, and testicular morphology. Used in male reproductive aging, hypogonadism research, and testosterone support protocols.
How does Testagen work? Testagen targets Leydig cell nuclei and regulates StAR protein and CYP17A1 enzyme expression, normalizing the steroidogenesis pathway for testosterone synthesis. It restores age-related decline in Leydig cell sensitivity to LH signaling and reduces testicular oxidative stress without being a hormone itself.
Benefits of Testagen: Normalizes Leydig cell function and testosterone synthesis; Non-hormonal approach to testosterone support; Reduces testicular oxidative stress; Restores LH receptor sensitivity; Male reproductive aging research; Supports fertility in male hypogonadism models; Complements gonadorelin/kisspeptin protocols
Testagen dosage: Standard Khavinson protocol: 1-2mg/day for 10 days, 2x per year. Monitor testosterone, LH, FSH. Complements gonadorelin or kisspeptin protocols.
Research status: Research Only
Source: PeptideWiki — https://www.peptide-wiki.net/peptides/testagen
Mechanism of Action
Testagen targets Leydig cell nuclei and regulates StAR protein and CYP17A1 enzyme expression, normalizing the steroidogenesis pathway for testosterone synthesis. It restores age-related decline in Leydig cell sensitivity to LH signaling and reduces testicular oxidative stress without being a hormone itself.
Benefits
- Normalizes Leydig cell function and testosterone synthesis
- Non-hormonal approach to testosterone support
- Reduces testicular oxidative stress
- Restores LH receptor sensitivity
- Male reproductive aging research
- Supports fertility in male hypogonadism models
- Complements gonadorelin/kisspeptin protocols
Side Effects & Risks
- Monitor testosterone and LH levels during use
- Generally well tolerated
- Injection site reactions
Where to Buy Testagen
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$39.99
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Storage & Reconstitution Guide
Storage Temperature
-20°C (lyophilized)
24 months (lyophilized), 28 days (reconstituted)
Reconstitution Solvent
Bacteriostatic water (BAC water)
Swirl gently — do not shake or vortex
Handling Notes
Protect lyophilized peptide from moisture and light. Once reconstituted, keep refrigerated. Discard if solution becomes cloudy or discolored. Use insulin syringe for precise dosing.
Step-by-Step Reconstitution
Gather supplies
BAC water, insulin syringe, alcohol swabs, vial
Disinfect tops
Swab rubber stoppers of both vials with alcohol
Draw BAC water
Pull desired mL of BAC water into syringe
Inject slowly
Inject BAC water down the side of the peptide vial, swirl gently to dissolve
Research Protocol
- Dose Range
- 1–2 mg
- Frequency
- Daily for 10-day courses
- Cycle
- 10-day courses, 2x per year
- Routes
- subcutaneous injection
- Notes
- Standard Khavinson protocol: 1-2mg/day for 10 days, 2x per year. Monitor testosterone, LH, FSH. Complements gonadorelin or kisspeptin protocols.
Legal & Regulatory Status
Sold for research purposes only. Not for human use. Laws vary by country.
Commonly Stacked With
View all peptide stacks →External Resources
Chemical Properties
- Mol. Weight
- ~480 Da
PeptideWiki Research Team
Evidence-based research data sourced from PubMed and ClinicalTrials.gov · Last updated: February 25, 2026
Frequently Asked Questions About Testagen
What is Testagen?▾
A tetrapeptide (Lys-Glu-Asp-Glu estimated) testes-targeting bioregulator from the Khavinson series. Normalizes Leydig cell function, testosterone synthesis, and testicular morphology. Used in male reproductive aging, hypogonadism research, and testosterone support protocols.
What are the benefits of Testagen?▾
Normalizes Leydig cell function and testosterone synthesis
What are the benefits of Testagen?▾
Non-hormonal approach to testosterone support
What are the side effects of Testagen?▾
Monitor testosterone and LH levels during use
What is the recommended dosage for Testagen?▾
Standard Khavinson protocol: 1-2mg/day for 10 days, 2x per year. Monitor testosterone, LH, FSH. Complements gonadorelin or kisspeptin protocols.
How long should a Testagen cycle last?▾
10-day courses, 2x per year
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