Side-by-side · Research reference

TB-500vsTestagen

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED8/46 cited

BAnimal-MechanisticHUMAN-REVIEWED11/41 cited

TB-500

Thymosin β4 fragment · Healing

2 mgPer doseGoldstein 2012

Phase 2Evidence levelGoldstein 2012

~2 hrHalf-life

SQ or IM · Multiple sites · 2–3×/week

Testagen

Bioregulator Peptide · Khavinson School

Lys-Glu-Asp-GlySequenceFedoreyeva 2011

NuclearLocalizationFedoreyeva 2011

TesticularTissue target

SQ · Abdomen · Cyclical

01Mechanism of Action

Parameter

TB-500

Testagen

Primary target

G-actin (sequestering) + cell-surface integrinsGoldstein 2012

Testicular tissue; proposed nuclear DNA interaction

Pathway

Actin remodelling → cell migration; integrin-linked signaling → angiogenesis; anti-inflammatory cytokine modulationGoldstein 2012 Malinda 1999

Nuclear penetration → DNA/oligonucleotide binding → gene expression modulation (bioregulator hypothesis)Fedoreyeva 2011

Downstream effect

Accelerated wound healing, endothelial migration, hair follicle regeneration, cardiac repair (preclinical)Goldstein 2012

Proposed support for spermatogenesis and testicular function; mechanistic data limited to nuclear localization and DNA interactionFedoreyeva 2011

Feedback intact?

Endogenous protein at baseline; supplementation amplifies

Unknown — no HPG axis data

Origin

17-AA active fragment of endogenous 43-AA thymosin β4 (TMSB4X gene)Goldstein 2012

Khavinson bioregulator school — isolated from testicular tissue peptide fractions

Antibody development

—

02Dosage Protocols

Parameter

TB-500

Testagen

Standard dose

2 mg per injectionGoldstein 2012

Anecdotal community range; clinical Phase 2 trials used 70–840 mcg/kg IV.

—

Frequency

2× per week (loading); then 1× per week (maintenance)

Once daily or alternate days

Lower / starter dose

1 mg per injection

—

Evidence basis

Animal-strong + Phase 2 dermal/ocular trialsGoldstein 2012

Animal mechanistic / in vitro onlyFedoreyeva 2011

Duration

4–8 weeks loading; longer maintenance for chronic injury

—

Reconstitution

Bacteriostatic water, 1–2 mL per 5 mg vial

Sterile water or bacteriostatic saline

Timing

Evening or pre-rest preferred (anecdotal)

—

Half-life

~2 hours (estimated; tissue uptake longer)

Unknown — likely minutes (short peptide)

Typical protocol (anecdotal)

—

100–200 mcg / day

No published human dosing studies; derived from Russian bioregulator practice.

Cycle length

—

10–20 days on, 10–14 days off

Bioregulator tradition uses pulsed cycles; no controlled data.

Route

—

Subcutaneous

04Side Effects & Safety

Parameter

TB-500

Testagen

Injection site reaction

Mild erythema, transient pain

—

GI symptoms

Rare nausea (anecdotal)

—

Cancer risk

Theoretical via angiogenesis pathway

—

Lethargy / fatigue

Reported anecdotally during loading phase

—

Antibody formation

No data (no long-term human trials)

—

Pregnancy / OB

Avoid

—

Long-term safety

Unknown beyond Phase 2

Unknown — no long-term studies

Injection site reactions

—

Erythema, mild irritation (potential)

Systemic effects

—

Unknown — no human safety data

Hormonal impact

—

No published data on testosterone, LH, FSH effects

Absolute Contraindications

TB-500

·Active malignancy (theoretical angiogenesis concern)
·Pregnancy / breastfeeding

Testagen

·Active testicular malignancy

Relative Contraindications

TB-500

·Cancer history
·Concurrent VEGF inhibitor therapy

Testagen

·Hormone-sensitive cancers (no data; theoretical caution)
·Pregnant or breastfeeding (no data)

05Administration Protocol

Parameter

TB-500

Testagen

1. Reconstitution

Add 1–2 mL bacteriostatic water to 5 mg vial → 2.5–5 mg/mL. Roll gently.

Add 1–2 mL sterile or bacteriostatic water to lyophilised vial. Swirl gently; do not shake. Solution should be clear.

2. Injection site

SQ near injury site (preferred), or systemic SQ (abdomen). Rotate sites.

Subcutaneous — abdomen or thigh. Rotate sites daily. Use standard insulin syringe (27–31G).

3. Timing

Evening or pre-sleep is most common anecdotal timing.

Morning or evening; no established optimal timing. Anecdotal preference: evening to align with circadian testosterone patterns.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate, ≤30 days.

Lyophilised: room temp, dark. Reconstituted: refrigerate 2–8 °C, use within 14–21 days if bacteriostatic water used.

5. Needle

27–31G, 4–8 mm insulin syringe.

10–20 days on, 10–14 days off. Bioregulator tradition uses pulsed exposure; rationale: prevent receptor/pathway desensitisation.

06Stack Synergy

TB-500

+ BPC-157

Strong

View BPC-157 →

TB-500 and BPC-157 cover complementary halves of tissue repair: BPC-157 upregulates VEGFR2-driven angiogenesis and fibroblast outgrowth; TB-500 sequesters G-actin to enable endothelial / epithelial migration. The anecdotal canonical "healing stack" — pairs especially well for tendon and ligament injuries.

TB-500: 2 mg SQ · 2× per week
BPC-157: 250–500 mcg SQ · daily
Primary benefit: Combined angiogenesis + cell migration for tendon/ligament/muscle repair

Testagen

— no documented stacks