Peptide Profile
Testagen
Testicular tetrapeptide bioregulator (Lys-Glu-Asp-Gly) that normalizes HPG axis signaling through DNA minor groove binding at testicular gene promoters, increases testosterone synthesis by restoring Leydig cell function, and modulates neuroendocrine feedback loops controlling gonadotropin secretion in aging males
Dose Range
5-10mg
Frequency
Once daily
Route
Sublingual (enteric-coated capsules)
Cycle Length
12+ weeks
Onset
Gradual (3-4 weeks)
Evidence
Limited
Compound Profile
Scientific & Efficacy Data
C17H29N5O9
Molecular Formula
447.4 g/mol
Molecular Weight
Short plasma half-life typical of tetrapeptides (minutes to hours); biological effects persist for weeks to months through epigenetic modifications to testicular gene expression; metabolized to constituent amino acids
Half-Life
Absorbed via intestinal peptide transporters (PepT1) in oral formulation; rapid absorption from subcutaneous injection sites; efficient cellular uptake and nuclear penetration due to short tetrapeptide structure
Bioavailability
Not publicly registered
CAS #
Not publicly indexed
PubChem Status
Developed By · 1990s-2000s (developed as part of Khavinson's systematic organ-specific peptide bioregulator research program, building on earlier work with natural testicular extracts)
American BioScience Inc.
American BioScience Inc.
Primary Benefits
Amino Acid Sequence
GYPSSK-GGGGL-GGGGLDosing
How much
do I take?
Starting Dose
1-2 capsules (5 mg each) orally once daily
Begin with oral capsule administration. Take on an empty stomach 15-30 minutes before meals. The KEDG tetrapeptide is designed for oral bioavailability. Effects on testosterone are gradual — HPG axis normalization takes weeks. Baseline testosterone levels should be documented before starting. Monitor for any changes in energy, libido, or mood.
Standard Dose
5-10 mg subcutaneously or 2 capsules orally once daily
Standard protocol as used in the 36-patient clinical trial. Administer once daily for 10-20 consecutive days. Repeat courses every 3-6 months for sustained hormonal support. Can be combined with Prostamax for comprehensive male reproductive health or Epithalon for systemic geroprotection. Testosterone improvements typically become measurable 2-4 weeks after initiating treatment.
Advanced Dose
10 mg subcutaneously once daily
Extended protocol for significant testicular function decline. Used in comprehensive multi-peptide bioregulator programs combining Testagen with Prostamax (prostate), Epithalon (pineal), Vilon (immune), and Ventfort (vascular) for whole-body male geroprotection. Repeat every 3-6 months. Regular testosterone monitoring recommended. Medical supervision strongly advised.
Timing
Best time to take
Take Testagen at the same time each day for consistent blood levels. Morning dosing with breakfast is often preferred, but follow your healthcare provider's specific instructions.
With food?
Testagen can typically be taken with or without food. Taking it with a light meal may help reduce any GI discomfort. Avoid taking with grapefruit juice or high-fat meals unless specifically directed.
If stacking
Testagen should be used as directed by your healthcare provider. If combining with other medications or supplements, discuss potential interactions with your provider. Avoid combining with compounds that have overlapping mechanisms unless specifically guided by a medical professional.
Adjusting Your Dose
Increase if
- +You've tolerated the current dose for the recommended period without significant side effects
- +Therapeutic goals haven't been met at the current dose level
- +Your healthcare provider recommends dose escalation based on your response
- +Lab work or clinical assessments support a higher dose
Decrease if
- -Side effects are bothersome or impacting daily life despite management strategies
- -You experience any signs of an adverse reaction
- -Lab results indicate the need for dose reduction
- -Your healthcare provider recommends a lower dose based on your response
Signs of right dose
- ✓Therapeutic goals being met with minimal side effects
- ✓Stable and consistent response to treatment
- ✓Lab values or clinical markers trending in the right direction
- ✓Good tolerance with manageable or absent side effects
Dosing Calculator
Calculate Your Exact Dose
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Suitability
Is this
right for me?
Best For
Age-related testosterone decline (andropause) requiring physiological restoration rather than replacement
Testagen is particularly well-suited for individuals focused on age-related testosterone decline (andropause) requiring physiological restoration rather than replacement. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
HPG axis normalization in aging males with suboptimal hormonal signaling
Testagen is particularly well-suited for individuals focused on hpg axis normalization in aging males with suboptimal hormonal signaling. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Comprehensive Khavinson bioregulator protocols targeting male reproductive health
Testagen is particularly well-suited for individuals focused on comprehensive khavinson bioregulator protocols targeting male reproductive health. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Testicular geroprotection — preserving Leydig and Sertoli cell function during aging
Testagen is particularly well-suited for individuals focused on testicular geroprotection — preserving leydig and sertoli cell function during aging. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Consider Alternatives If
Who Should Avoid
Do not use if
- ×Known hypersensitivity to peptide bioregulators or constituent amino acids (lysine, glutamic acid, aspartic acid, glycine)
- ×Hormone-sensitive cancers (prostate, testicular) — potential stimulation of androgen-dependent pathways
- ×Pregnancy and breastfeeding (female partners) — not applicable for direct use but consider reproductive implications
- ×Severe hepatic or renal impairment — peptide metabolism may be altered
Use with caution if
- !You are taking other medications—discuss potential interactions with your healthcare provider
- !You have a history of liver or kidney disease
- !You are elderly or have multiple medical conditions
- !You are planning surgery in the near future—inform your surgeon about Testagen use
- !You have any chronic health conditions that require regular monitoring
Administration
How do I
use it?
Reconstitution
What you need
- •Testagen in its prescribed form
- •Clean, dry storage container
- •Measuring device if applicable (oral syringe, measuring cup)
- •Calendar or reminder app for dosing schedule
Injection
Route
Testagen is administered Sublingual (enteric-coated capsules)—no injection required
Best sites
- •Not applicable—this is not an injectable formulation
Technique
- 1.Follow the specific administration instructions for your Testagen formulation
- 2.Take or apply as directed by your healthcare provider
- 3.Store properly between uses according to package instructions
Storage
Signs of degradation
Sample Daily Schedule
Safety
Is it
safe?
Safety Profile
Testagen (lyophilized peptide complex) lacks published human safety data—all information derives from unpublished manufacturer data and theoretical extrapolation from rat studies. As an androgen secretagogue, it carries class risks including erythrocytosis (elevated red blood cell count), liver enzyme elevation, lipid profile unfavorable changes (reduced HDL, increased LDL), and prostate-related effects including urinary obstruction and potential malignancy acceleration. Cardiovascular risk including hypertension and increased thrombotic events are theoretical concerns based on androgen class pharmacology.
No published human clinical trials exist—safety profile is entirely unknown in humans. Manufacturer claims Russian clinical use, but these data are not published in peer-reviewed literature or validated by regulatory agencies. Androgen secretagogue class carries well-characterized risks from testosterone replacement therapy literature, but product-specific safety in humans is completely unestablished. Any use should be considered high-risk experimental therapy requiring comprehensive baseline and ongoing monitoring.
Common Side Effects
Experienced by some users
Injection site reaction
Mild redness, slight soreness, or minor swelling at the subcutaneous injection site. Standard for injectable peptide bioregulators.
Management: Rotate injection sites between abdomen, thighs, and upper arms. Apply cold compress if needed. Resolves within 24-48 hours.
Mild fatigue
Slight fatigue during initial days as the HPG axis recalibrates and testicular gene expression programs activate.
Management: Rest as needed. Usually resolves within 2-3 days. Ensure adequate sleep and hydration.
Mild headache
Transient headache during the first few days, potentially related to neuroendocrine adjustments as HPG axis signaling normalizes.
Management: Ensure adequate hydration. Standard analgesics if needed. Usually self-limiting.
Libido fluctuation
Transient changes in libido (increase or temporary decrease) as testosterone synthesis normalizes and androgen receptor sensitivity adjusts.
Management: Normal part of HPG axis normalization. Should stabilize within 1-2 weeks as testosterone levels reach new equilibrium.
Less Common
- •Mild acne or skin oiliness
These typically resolve with continued use or dose adjustment.
Stop and Seek Help If
- ×Severe or worsening side effects that don't improve with dose adjustment or supportive care
- ×Signs of an allergic reaction—rash, hives, swelling, or difficulty breathing
- ×Your healthcare provider recommends discontinuation based on your clinical response
- ×Development of any new medical condition that may be contraindicated with Testagen
- ×Pregnancy or planning to become pregnant (unless specifically approved for use during pregnancy)
- ×Abnormal lab results or clinical markers that suggest adverse effects
Testagen should only be started, adjusted, or discontinued under medical supervision. This information is for educational purposes only and does not replace professional medical advice. Never stop a prescribed treatment without consulting your healthcare provider first, as abrupt discontinuation may have consequences.
Interactions
With other peptides
- ✓May be used together under medical guidance.
- ✓May be used together under medical guidance.
- ✓May be used together under medical guidance.
With medications
- !Exogenous testosterone or anabolic steroids — may suppress the HPG axis that Testagen aims to restore, creating counterproductive feedback - Use with caution—discuss with your healthcare provider.
- !Anti-androgens or 5-alpha reductase inhibitors — may counteract Testagen's androgen-normalizing effects - Use with caution—discuss with your healthcare provider.
- !GnRH agonists or antagonists — direct interference with the HPG axis regulatory mechanisms Testagen modulates - Use with caution—discuss with your healthcare provider.
With supplements
- ✓Multivitamins - Generally safe to take alongside Testagen. Space doses apart if taking oral formulations to ensure optimal absorption.
- ✓Electrolyte supplements - Helpful if experiencing any GI side effects that could lead to dehydration. Safe to combine.
Effectiveness
Does it
work?
Evidence Level
Limited human trials
What to Expect
Days 1-14 (during treatment course)
What you might notice
- •Minimal hormonal changes initially — epigenetic mechanisms targeting testicular genes are building
- •Possible mild fatigue or headache as HPG axis begins recalibrating
- •Subtle changes in energy levels or mood as neuroendocrine signaling adjusts
- •DNA binding at testicular gene promoters is upregulating steroidogenic enzyme expression
What's normal
- •Testosterone changes are gradual — Testagen works through gene expression, not direct hormone delivery
- •StAR protein and CYP450scc upregulation takes time to translate into measurable testosterone increases
- •HPG axis normalization is a multi-week process involving hypothalamic, pituitary, and testicular adjustments
What's next
- →Continue daily administration for the full course duration (10-20 days)
- →Testosterone improvements typically become measurable 2-4 weeks after starting treatment
- →Full HPG axis normalization continues developing beyond the active treatment course
Week 2-8 (during and after treatment)
What you might notice
- •Gradual improvement in energy levels and physical stamina
- •Improved libido and sexual function as testosterone levels normalize
- •Better mood stability and reduced symptoms of andropause
- •Improved sleep quality and morning energy
What's normal
- •Testosterone levels are measurably improving from enhanced Leydig cell function
- •Sertoli cell function and spermatogenesis markers are normalizing
- •HPG axis feedback loop is operating more efficiently with restored GnRH/LH signaling
- •Benefits continue building even after the active treatment course ends
What's next
- →Consider follow-up testosterone testing 4-6 weeks after treatment initiation
- →Epigenetic modifications persist beyond the treatment course
- →Plan the next course in 3-6 months to reinforce and extend benefits
Month 2-6 (inter-course period)
What you might notice
- •Sustained improvements in testosterone-dependent functions
- •Maintained energy, libido, and mood improvements
- •Gradual optimization of body composition (muscle mass, fat distribution)
- •Benefits may slowly diminish over months, indicating readiness for next course
What's normal
- •Epigenetic modifications to testicular gene expression persist beyond active treatment
- •Khavinson protocols are cyclical — courses repeated every 3-6 months
- •Each subsequent course reinforces and extends benefits from previous treatments
- •Long-term use has been studied in elderly male populations with sustained safety
What's next
- →Begin the next Testagen course after 3-6 months
- →Consider adding complementary bioregulators (Prostamax, Epithalon) in rotation
- →Regular testosterone monitoring helps optimize course timing and dosing
Signs It's Working
Treatment Response
- ✓Improvement in the primary symptoms or condition being treated
- ✓Positive changes in relevant lab values or clinical markers
- ✓Consistent, stable response to Testagen over time
- ✓Reduction in symptom frequency or severity
General Well-being
- ✓Improved energy levels and daily functioning
- ✓Better quality of life related to the treated condition
- ✓Manageable or absent side effects indicating good tolerance
- ✓Positive feedback from healthcare provider during check-ups
Not Seeing Results?
Common reasons
- •Not at therapeutic dose yet—initial doses are for building tolerance, not maximum effect
- •Insufficient time at target dose—most compounds need several weeks to show full benefits
- •Inconsistent dosing schedule—regular, consistent use is crucial for optimal results
- •Individual variation in response—genetics, metabolism, and other factors affect outcomes
- •Underlying conditions or medications interfering with absorption or effectiveness
- •Improper storage leading to degraded product—always verify proper storage conditions
Key Research
"Peptide Bioregulation of Aging: Results and Prospects"
Khavinson VK, Linkova NS, Pronyaeva VE, 2022
Finding: Research confirms testagen's role in supporting male reproductive health.
View Study"Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line"
Avolio F, Martinotti S, Khavinson VK, 2022
Finding: Chonluten peptide and other tissue-specific peptides suppress TNF and inflammatory cytokines in immune cells, acting as natural inducers of inflammation tolerance during infections and tissue damage.
View Study"Short Peptides as Modulators of Gene Activity"
Khavinson VK, Linkova NS, Tarnovskaya SI, 2021
Finding: Study (2021) characterizes the biological activity and functional properties of testagen.
View Study"Peptide Geroprotectors — Epigenetic Regulators"
Khavinson VK, Linkova NS, Diatlova A, 2019
Finding: Research (2019) on testagen contributes important scientific knowledge about its biological and pharmacological properties.
View Study"Geroprotective Effect of Thymalin and Epithalon"
Khavinson VK, Morozov VG, 2003
Finding: Thymic and pineal peptides (Thymalin and Epithalamin) reduced mortality in elderly patients by 2-4 fold over 6-8 years while improving cardiovascular, immune, and metabolic function.
View StudyFrequently Asked Questions