Side-by-side · Research reference

HexarelinvsTeriparatide

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

BFDA-ApprovedHUMAN-REVIEWED10/62 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

Teriparatide

PTH (1-34) Fragment · FDA-Approved

20 mcgDaily dose

12-18 moAnabolic windowFerrari 2026

SQRoute

SQ · Thigh/Abdomen · Once Daily

01Mechanism of Action

Parameter

Hexarelin

Teriparatide

Primary target

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

Parathyroid hormone 1 receptor (PTH1R) on osteoblastsXue 2026

Pathway

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

PTH1R activation → cAMP/PKA signaling → osteoblast differentiation and activity

Downstream effect

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

Stimulates osteoblast formation and bone matrix deposition; increases bone mineral density at trabecular and cortical sites

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

Yes — intermittent dosing preserves anabolic effect; continuous exposure causes catabolic bone resorption

Origin

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

Recombinant 34-amino-acid N-terminal fragment of 84-amino-acid human PTH

Antibody development

—

02Dosage Protocols

Parameter

Hexarelin

Teriparatide

Standard dose

100–200 mcg per injectionSmith 1996

—

Frequency

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

Once daily

Intermittent administration preserves anabolic effect.

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

RCT / FDA-approved

Duration

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

—

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

Morning or evening (flexible)

Half-life

~70 minSemenistaya 2010

—

Standard dose (osteoporosis)

—

20 mcg / day

FDA-approved regimen for severe osteoporosis.

Maximum duration

—

24 months lifetime

Anabolic effect wanes after 12-18 months; FDA recommends max 2-year cumulative exposure.

Hypoparathyroidism dose

—

20 mcg / day

Used off-label for chronic hypoparathyroidism.

Pelvic fragility fractures

—

20 mcg / day × 8-12 weeks

Accelerates fracture healing; reduces time to union.Crooks 2026

Route

—

Subcutaneous (thigh or abdomen)

Storage

—

Refrigerate 2-8 °C; pen device stable at room temp for 28 days after first use

Pharmacogenetics

—

ALDH2 polymorphisms may influence BMD responseObara 2026

ALDH2*2 variant carriers show altered PTH receptor expression.Obara 2026

03Metabolic / Fat Loss Evidence

Parameter

Hexarelin

Teriparatide

Fat loss application

—

None — teriparatide is a bone anabolic agent without direct lipolytic activity

04Side Effects & Safety

Parameter

Hexarelin

Teriparatide

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

—

Hypercalcemia

—

Transient serum calcium elevation 4-6 hours post-injection

Monitor serum calcium; usually asymptomatic.

Orthostatic hypotension

—

Dizziness, lightheadedness within hours of injection

Nausea

—

Common, usually mild and transient

Leg cramps / Arthralgia

—

Musculoskeletal pain reported in clinical trials

Hypercalciuria

—

Increased urinary calcium excretion; monitor for nephrolithiasis risk

Osteosarcoma (black box warning)

—

Rat studies showed dose-dependent osteosarcoma; not observed in humans to date; contraindicated in Paget's disease, skeletal malignancy, prior radiation

Injection site reaction

—

Erythema, bruising, pain (uncommon)

Absolute Contraindications

Hexarelin

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

Teriparatide

·Paget's disease of bone (increased baseline osteosarcoma risk)
·Unexplained elevated alkaline phosphatase
·Prior skeletal radiation therapy
·Skeletal malignancies or bone metastases
·Hypercalcemic disorders (primary hyperparathyroidism)
·Pregnancy / lactation

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

Teriparatide

·Active or recent nephrolithiasis
·Severe renal impairment (CKD G4-G5)
·Hypercalciuria without adequate monitoring

05Administration Protocol

Parameter

Hexarelin

Teriparatide

1. Reconstitution

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

Teriparatide is supplied in pre-filled pen injectors (Forteo pen). Store refrigerated at 2-8 °C until first use. After first injection, pen may be kept at room temperature for up to 28 days. Do not freeze.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Subcutaneous injection into thigh or lower abdomen. Rotate sites daily to avoid lipodystrophy. Avoid areas with scars, bruises, or active skin conditions.

3. Timing

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

Once daily, at approximately the same time each day. Morning or evening administration is acceptable. Take while sitting or lying down to minimize orthostatic hypotension risk.

4. Storage

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

Clean injection site with alcohol swab. Pinch skin, insert needle at 90° angle, and inject full dose (20 mcg). Hold for 5 seconds before withdrawing needle. Do not rub injection site.

5. Needle

29–31G, 4–8 mm insulin syringe.

Baseline and periodic monitoring of serum calcium, urinary calcium, serum PTH (if hypoparathyroidism), and bone mineral density (DXA scan). Monitor for hypercalcemia 4-6 hours post-dose if symptomatic.

6. Calcium and vitamin D supplementation

—

Ensure adequate calcium (1000-1200 mg/day) and vitamin D (800-1000 IU/day) intake unless contraindicated by hypercalcemia or hypercalciuria.

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

Teriparatide

— no documented stacks