Pepbase

Testagen

Also known as: KEDG Tetrapeptide

Not FDA Approved
Hormone OptimizationRecoveryAnti-Aging

Primary use: Endocrine regulation and hormonal balance

ℹ️

What is Testagen?

Testagen, also known as KEDG, is a synthetic tetrapeptide bioregulator developed by Vladimir Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology. It primarily targets anterior pituitary gland function, aiming to regulate TSH levels and indirectly support testosterone and thyroid hormone production. Although it is approved as a supplement in Russia, it remains unapproved by the FDA with primary usage based on preclinical research. Potential risks include hormonal fluctuations and contraindications in thyroid cancer or hyperthyroidism.

Primary Benefits
  • Supports thyroid function
  • May enhance testosterone levels
  • Promotes reproductive health
How It Works

Testagen crosses cell and nuclear membranes to interact directly with DNA, modulating gene expression in pituitary cells. This interaction may stimulate TSH release and subsequently influence thyroid and testosterone activity, potentially optimizing hormone levels.

⚠️

Safety Tips

Precautions reported in community discussions and literature. This is not a complete list. View Full Side Effects Guide →
  • 1DON'T use if you have thyroid cancer or hyperthyroidism.
  • 2AVOID using unverified peptide sources without third-party testing.
  • 3NEVER share needles to prevent infections.
  • 4DON'T exceed recommended doses without consulting a healthcare professional.
  • 5AVOID use during pregnancy or breastfeeding.

Who Should NOT Use

  • Thyroid cancer
  • Hyperthyroidism
  • Pregnancy
  • Breastfeeding

Dosage & Protocols

Different purposes have different protocols, dosing, and considerations

💉

Thyroid function optimization

limited evidence

Testagen is researched for its potential to influence thyroid hormone production through TSH modulation, impacting T3/T4 levels.

Evidence: Preclinical studies in avian models demonstrate effects on TSH release and thyroid function.

The following are ranges reported in published literature and community discussions. These are NOT recommendations or medical advice.

Range
100-300 mcg
Frequency
once daily
Cycle
8-12 weeks
Route
Subcutaneous
TimingMorning
NotesAligns with natural circadian hormone rhythms

📋Community-Reported Protocols

Not recommendations:

The following protocols are compiled from online communities and published literature. Pepbase does not endorse, recommend, or verify these protocols. They are provided for informational purposes only. Individual responses vary significantly. Consult a licensed medical professional before any use.

Reported GoalReported DoseReported FrequencyReported Route
Starting / Titration100mcgOnce dailySubcutaneous injection
Building phase150mcgOnce dailySubcutaneous injection
Standard phase200mcgOnce dailySubcutaneous injection
Maximum phase250-300mcgOnce dailySubcutaneous injection

⏱️Pharmacokinetics

Half-Life
30 min
Time to Peak
15 min
Clearance
~2.5 hours

⚡Reported Side Effects

This is not a complete list. Other side effects may occur.

Common
Hormonal fluctuationsreported (frequency unknown)
Mood changesreported (frequency unknown)
Serious / Rare
  • • Allergic reactions
  • • Thyroid function alteration
Injection-Specific Warnings
  • Rotate injection sites to prevent tissue damage
  • Use sterile technique

🧊Storage

Temperature
-20°C
Reconstituted
2-8°C
Shelf Life
Refer to supplier details
Light Sensitive
Yes - protect from light
💉

Testosterone support

limited evidence

Testagen is hypothesized to indirectly support testosterone levels through enhancement of thyroid function.

Evidence: Testagen's impact on testosterone is noted in conjunction with improvements in TSH levels.

The following are ranges reported in published literature and community discussions. These are NOT recommendations or medical advice.

Range
100-300 mcg
Frequency
once daily
Cycle
8-12 weeks
Route
Subcutaneous
TimingMorning
NotesConsistent daily timing is crucial for stable peptide levels

📋Community-Reported Protocols

Not recommendations:

The following protocols are compiled from online communities and published literature. Pepbase does not endorse, recommend, or verify these protocols. They are provided for informational purposes only. Individual responses vary significantly. Consult a licensed medical professional before any use.

Reported GoalReported DoseReported FrequencyReported Route
Initial phase100mcgOnce dailySubcutaneous injection
Maintenance200-300mcgOnce dailySubcutaneous injection

⏱️Pharmacokinetics

Half-Life
30 min
Time to Peak
15 min
Clearance
~2.5 hours

⚡Reported Side Effects

This is not a complete list. Other side effects may occur.

Common
Hormonal fluctuationsreported (frequency unknown)
Mood changesreported (frequency unknown)
Serious / Rare
  • • Allergic reactions
  • • Thyroid function alteration
Injection-Specific Warnings
  • Rotate injection sites to prevent tissue damage
  • Use sterile technique

🧊Storage

Temperature
-20°C
Reconstituted
2-8°C
Shelf Life
Refer to supplier details
Light Sensitive
Yes - protect from light
🛡️

Harm Reduction Information

Quality Concerns

  • Verify source with COA for purity
  • Avoid yellow/brown coloration in reconstituted solutions

Safety Tips

  • Use bacteriostatic water for reconstitution
  • Start with lower doses to assess tolerance
  • Rotate injection sites to avoid damage

Warning Signs to Stop

  • Unexpected severe mood changes
  • Signs of allergic reactions (e.g., rashes, difficulty breathing)

Seek Medical Help Immediately If

  • If experiencing severe allergic reactions
  • If significant hormonal imbalance symptoms occur
❓

Frequently Asked Questions

How long until I see effects?

Testagen's effects may become noticeable around weeks 4-8 for hormonal effects, as it is a bioregulator not a hormone.

What time of day should I take it?

It is recommended to administer Testagen in the morning to align with natural hormone rhythms.

How can I minimize side effects?

To minimize side effects, use Testagen under medical supervision, start with lower doses, and monitor for any adverse reactions.

Does tolerance develop?

Testagen does not have significant reports of tolerance development, but cycling is advisable.

How should I store it?

Store lyophilized Testagen at -20°C and reconstituted peptide at 2-8°C.

Do I need to cycle it?

Yes, it is recommended to cycle Testagen for 8-12 weeks with a break of 4-6 months between cycles.

🔄

Reported Combinations

Compounds reported to be used alongside Testagen in community discussions. Not a recommendation.

recreational

Epitalon

Synergistic for pituitary function support

recreational

CJC-1295

Works well together for hormone optimization

recreational

BPC-157

Supports tissue repair alongside hormonal balance

⚠️

Reported Interactions

Interactions reported in literature and community discussions.

Thyroid medicationsmoderate

Monitor thyroid function closely if using thyroid medication.

Testosterone replacementmoderate

Potential interactions with testosterone levels.

Epitalonmoderate

May enhance effects due to synergistic action.

Reconstitution Guide

Reconstitution Calculator

mL
U100 insulin syringe01020304050607080901001mL

100 units = 1 mL

Safety Tips

  • Always consult a licensed medical professional for dosing and reconstitution instructions.
  • Always double check your units. Mixing up mg and mcg can be very dangerous.
  • Make sure to select your syringe type. U-100 and U-50 syringes have different units.
  • Ensure you're not adding more BAC than your vial can hold. Most vials have maximum capacities listed.

This calculator is for informational and educational purposes only. It does not provide medical advice, dosing recommendations, or safety determinations. Reference ranges shown are compiled from publicly available sources and are not a substitute for guidance from a licensed healthcare professional.

Explore More Research

Browse our database of peptide research information compiled from published literature and community sources.

Browse All PeptidesAbout Pepbase App
📚

Other Sources & Citations

PubMed
The Inhibitory Effect and Adsorption Properties of Testagen Peptide ...
pmc.ncbi.nlm.nih.gov•Updated Jan 2026
corepeptides
Testagen Peptide: Thyroid Research and Studies on ...
corepeptides.com•Updated Jan 2026
PubMed
The Inhibitory Effect and Adsorption Properties of Testagen Peptide ...
pubmed.ncbi.nlm.nih.gov•Updated Aug 2025
exploring-peptides
Testagen - Exploring Peptides
exploring-peptides.com•Updated Nov 2025

Last updated: October 2, 2023

Important Disclaimer

AI-Generated Content Notice

The information on this page has been compiled using artificial intelligence (AI) and large language model (LLM) technology from multiple sources including published literature, online communities, and public databases. This content may contain errors, inaccuracies, outdated information, or omissions. We make no guarantees regarding the accuracy, completeness, or reliability of any information presented. You are solely responsible for independently verifying any information before relying on it.

Not Medical Advice

Nothing on this website constitutes medical advice, diagnosis, or treatment recommendations. The information provided is for educational and harm-reduction purposes only. We do not provide individualized dosing guidance or treatment recommendations. Protocols and dosing information shown represent reports from community discussions and published literature—they are not endorsements or recommendations. Always consult with a licensed healthcare professional before making any health-related decisions.

No Endorsement of Use

Pepbase does not endorse, encourage, or recommend the use of any peptide or substance discussed on this website. Many compounds discussed are not approved for human use by the FDA or other regulatory agencies. Some substances may be illegal to possess, sell, or use in your jurisdiction. We do not facilitate or encourage the procurement, distribution, or use of controlled or prescription-only substances. Users are solely responsible for understanding and complying with all applicable laws in their jurisdiction.

Calculators and Tools

Any calculators, estimators, or tools provided on this website are for informational purposes only and produce estimates that may be inaccurate. Errors in calculations can result in serious harm. You are solely responsible for verifying all calculations independently. These tools do not account for individual factors that may affect dosing and should never be relied upon as a substitute for professional medical guidance.

Assumption of Risk

By using this website, you acknowledge that you understand the risks associated with using unregulated substances and that you assume full responsibility for your own health decisions. Pepbase, its creators, contributors, and affiliates disclaim all liability for any harm, injury, or damages arising from the use or misuse of information on this website. Use of any information on this site is entirely at your own risk.

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