Side-by-side · Research reference

HexarelinvsTestagen

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

APhase 1HUMAN-REVIEWED19/45 cited

BAnimal-MechanisticHUMAN-REVIEWED11/41 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

Testagen

Bioregulator Peptide · Khavinson School

Lys-Glu-Asp-GlySequenceFedoreyeva 2011

NuclearLocalizationFedoreyeva 2011

TesticularTissue target

SQ · Abdomen · Cyclical

01Mechanism of Action

Parameter

Hexarelin

Testagen

Primary target

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

Testicular tissue; proposed nuclear DNA interaction

Pathway

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

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

Downstream effect

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

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

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

Unknown — no HPG axis data

Origin

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

Khavinson bioregulator school — isolated from testicular tissue peptide fractions

Antibody development

—

02Dosage Protocols

Parameter

Hexarelin

Testagen

Standard dose

100–200 mcg per injectionSmith 1996

—

Frequency

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

Once daily or alternate days

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

Animal mechanistic / in vitro onlyFedoreyeva 2011

Duration

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

—

Reconstitution

Bacteriostatic water

Sterile water or bacteriostatic saline

Timing

Pre-sleep + fasted preferred

—

Half-life

~70 minSemenistaya 2010

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

Hexarelin

Testagen

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)

—

Pregnancy / OB

Avoid

—

Injection site reactions

—

Erythema, mild irritation (potential)

Systemic effects

—

Unknown — no human safety data

Hormonal impact

—

No published data on testosterone, LH, FSH effects

Long-term safety

—

Unknown — no long-term studies

Absolute Contraindications

Hexarelin

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

Testagen

·Active testicular malignancy

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

Testagen

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

05Administration Protocol

Parameter

Hexarelin

Testagen

1. Reconstitution

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

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

2. Injection site

SQ — abdomen or thigh. Rotate sites.

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

3. Timing

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

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

29–31G, 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

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

Testagen

— no documented stacks