Side-by-side · Research reference

HCGvsTB-500

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

AFDA-ApprovedHUMAN-REVIEWED12/52 cited

BPhase 2HUMAN-REVIEWED8/46 cited

HCG

Glycoprotein Hormone · LH Mimetic

2,000 IUTypical dose (2×/wk)Konsam 2026 Zachariou 2026

70–90%Sperm induction rateHuijben 2026 Zachariou 2026

12–24 moTime to sperm appearanceHuijben 2026 Nariyoshi 2025

IM or SQ · 2–3×/week

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

01Mechanism of Action

Parameter

HCG

TB-500

Primary target

LH receptors on testicular Leydig cellsSchröder-Lange 2025

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

Pathway

hCG → Leydig cell LH receptor → Intracellular cAMP → Steroidogenesis pathway activation → Testosterone synthesis

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

Downstream effect

Elevated intratesticular testosterone, restored spermatogenesis, virilization, secondary sex characteristic developmentKonsam 2026 Zachariou 2026

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

Feedback intact?

No — exogenous hCG bypasses hypothalamic-pituitary axis; endogenous LH remains suppressed

Endogenous protein at baseline; supplementation amplifies

Origin

Heterodimeric glycoprotein (alpha subunit shared with LH/FSH/TSH; beta subunit confers specificity). Available as urinary-derived or recombinant formulations.

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

Antibody development

Rare with recombinant; possible with urinary-derived formulations

—

02Dosage Protocols

Parameter

HCG

TB-500

Hypogonadotropic hypogonadism (monotherapy)

2,000 IU IM/SQ 2–3×/weekKonsam 2026 Zachariou 2026

Titrate to normalize testosterone (300–1,000 ng/dL) or achieve target AMH ~7.4 ng/mL.

—

Combined therapy (hCG + FSH)

hCG 2,000 IU 2×/wk + rFSH 75 IU 3×/wkKonsam 2026 Nariyoshi 2025

Preferred for azoospermia; FSH added after initial hCG phase or from outset.

—

Triple therapy (experimental)

hCG 2,000 IU 2×/wk + rFSH 75 IU 3×/wk + testosterone 100 mg IM q2wkKonsam 2026

May accelerate virilization; reduces hCG requirements (~30% lower cumulative dose vs monotherapy).

—

Cryptorchidism (pediatric)

500–4,000 IU IM 2–3×/week for 3–6 weeks

—

Evidence basis

RCT / Meta-analysis / FDA-approvedKonsam 2026 Huijben 2026

Animal-strong + Phase 2 dermal/ocular trialsGoldstein 2012

Duration to sperm appearance

12–24 months (median ~18 mo)Huijben 2026 Zachariou 2026

Congenital HH may require longer treatment; acquired HH responds faster.

—

Route

Intramuscular or subcutaneousKonsam 2026

—

Monitoring

Serum testosterone, semen analysis q3–6mo, testicular ultrasound

Thickened seminiferous tubules (>300 μm) on ultrasound predict imminent sperm appearance.Nariyoshi 2025

—

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)

Lower / starter dose

—

1 mg per injection

Duration

—

4–8 weeks loading; longer maintenance for chronic injury

Reconstitution

—

Bacteriostatic water, 1–2 mL per 5 mg vial

Timing

—

Evening or pre-rest preferred (anecdotal)

Half-life

—

~2 hours (estimated; tissue uptake longer)

04Side Effects & Safety

Parameter

HCG

TB-500

Injection site reaction

Pain, erythema (mild, transient)

Mild erythema, transient pain

Gynecomastia

Aromatization of elevated testosterone to estradiol; dose-dependent

—

Testicular discomfort / Edema

Rapid testicular growth in hypogonadal males; usually self-limiting

—

Polycythemia

Elevated hematocrit from supraphysiological testosterone; monitor CBC

—

Mood / Libido changes

Variable; usually positive with normalization of testosterone

—

Acne / Oily skin

Androgen-mediated; dose-dependent

—

Prostate concerns

Monitor PSA in older males; hCG restores physiological testosterone (not supraphysiological)

—

Antibody formation

Rare with recombinant; possible with urinary-derived

No data (no long-term human trials)

GI symptoms

—

Rare nausea (anecdotal)

Cancer risk

—

Theoretical via angiogenesis pathway

Lethargy / fatigue

—

Reported anecdotally during loading phase

Pregnancy / OB

—

Avoid

Long-term safety

—

Unknown beyond Phase 2

Absolute Contraindications

HCG

·Androgen-dependent malignancy (prostate, breast cancer)
·Hypersensitivity to hCG or excipients
·Precocious puberty

TB-500

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

Relative Contraindications

HCG

·Untreated obstructive sleep apnea
·Severe cardiovascular disease (polycythemia risk)
·History of thromboembolism

TB-500

·Cancer history
·Concurrent VEGF inhibitor therapy

05Administration Protocol

Parameter

HCG

TB-500

1. Reconstitution (if lyophilized)

Add sterile water or bacteriostatic water per manufacturer instructions. Typically 1–2 mL per 5,000–10,000 IU vial. Roll gently — do not shake. Solution should be clear.

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

2. Injection site

Intramuscular: ventrogluteal, vastus lateralis, or deltoid. Subcutaneous: abdomen, avoiding navel (2-inch radius). Rotate sites to prevent lipohypertrophy.

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

3. Timing

Administer 2–3 times per week. Consistent weekly schedule recommended (e.g., Monday/Thursday or Monday/Wednesday/Friday).

Evening or pre-sleep is most common anecdotal timing.

4. Storage

Lyophilized: room temperature, light-protected. Reconstituted: refrigerate 2–8 °C. Bacteriostatic water extends shelf life to ~30 days; sterile water use within 72 hours.

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

5. Needle selection

IM: 21–23G, 1–1.5 inch. SQ: 25–27G, 5/8 inch. Inject slowly (30–60 seconds for IM).

27–31G, 4–8 mm insulin syringe.

06Stack Synergy

HCG

— no documented stacks

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