Side-by-side · Research reference

HexarelinvsThymosin α-1

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

APhase 1Reviewed19/45 cited

BPhase 3Reviewed8/39 cited

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

SQ · Multiple sites · 1–3×/day

Thymosin α-1

Immune modulator · Approved (some countries)

1.6 mgPer doseIyer 2007

Phase 3Evidence levelIyer 2007 Camerini 2001

~2 hrHalf-life

SQ · 2× weekly · 6+ months for chronic indications

01Mechanism of Action

Parameter

Hexarelin

Thymosin α-1

Primary target

Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996 Ghigo 1997

Toll-like receptor 9 (TLR9) + T-cell maturation pathwayCamerini 2001

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997

TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturationIyer 2007

Downstream effect

Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997

Restored T-cell function, improved viral clearance, anti-tumour adjuvant effectsIyer 2007

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

—

Origin

Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996

Synthetic 28-AA peptide identical to natural Tα-1 isolated from thymus extractCamerini 2001

Antibody development

—

02Dosage Protocols

Parameter

Hexarelin

Thymosin α-1

Standard dose

100–200 mcg per injectionSmith 1996

—

Frequency

1–2× per day max (tachyphylaxis with chronic 3× daily)

2× weekly (Mon/Thu typical)

Lower / starter dose

50 mcg per dose

0.8 mg per injection

Evidence basis

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

Phase 3 + approved (35+ countries as Zadaxin)Iyer 2007

Duration

4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)

6–12 months for chronic indications

Reconstitution

Bacteriostatic water

Sterile water for injection per vial label

Timing

Pre-sleep + fasted preferred

No specific time

Half-life

~70 minSemenistaya 2010

~2 hours plasma; tissue effect days

Standard dose (HBV/HCV)

—

1.6 mg SQ 2× weekly × 6–12 monthsIyer 2007

04Side Effects & Safety

Parameter

Hexarelin

Thymosin α-1

Cortisol elevation

Modest at high dosesGhigo 1997

—

Prolactin elevation

Modest at high dosesGhigo 1997

—

Hunger

Strong appetite increase via ghrelin agonism

—

Tachyphylaxis

Receptor desensitisation with chronic dosingGhigo 1997

—

Cardiac effects

Direct cardio-tropic; potential benefit in MI but unstudied in humansGhigo 1997

—

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy (GH/IGF-1 axis)

No signal — used as adjuvant in oncology

Pregnancy / OB

Avoid

Injection site reaction

—

Erythema, mild discomfort

GI symptoms

—

Rare nausea

Fatigue

—

Common during initial weeks

Fever / flu-like

—

Mild interferon-like response possible

Autoimmune

—

Theoretical risk; caution in active autoimmune disease

Absolute Contraindications

Hexarelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Thymosin α-1

·Pregnancy / breastfeeding
·Hypersensitivity to peptide
·Concurrent immunosuppressant therapy (transplant patients)

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

Thymosin α-1

·Active autoimmune disease
·Severe immunocompromised state without supervision

05Administration Protocol

Parameter

Hexarelin

Thymosin α-1

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

Add 1 mL sterile water per 1.6 mg vial → 1.6 mg/mL.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

SQ — abdomen, thigh, or upper arm. Rotate sites.

3. Timing

Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.

2× weekly, e.g. Monday + Thursday.

4. Storage

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

Lyophilised: refrigerate. Reconstituted: refrigerate, use within 24 h.

5. Needle

29–31G, 4–8 mm insulin syringe.

27–31G, 4–8 mm insulin syringe.

06Stack Synergy

Hexarelin

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

Hexarelin (GHRP) + CJC-1295-no-DAC (GHRH analogue) is the higher-amplitude variant of the standard GHRH+GHRP stack. Hexarelin produces a stronger pulse than ipamorelin but with cortisol + prolactin signal — choose this stack for maximum GH amplitude when side-effect tolerance is acceptable. Cycle aggressively.

Hexarelin: 100 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Maximum GH pulse amplitude (with side-effect signal)

Smith 1996 Teichman 2006

Thymosin α-1

— no documented stacks