Side-by-side · Research reference

DihexavsHGH 191AA

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

AAnimal-StrongHUMAN-REVIEWED7/28 cited

BFDA-ApprovedHUMAN-REVIEWED0/75 cited

Dihexa

Angiotensin IV Analogue · Pre-Clinical

Pre-clinicalDevelopment stage

Rodent onlyEvidence basisBenoist 2014

HGF/c-MetTarget systemWright 2015

Not established — animal studies only

HGH 191AA

Recombinant hGH · FDA-Approved

0.024–0.034 mg/kg/dayPediatric GHD dose

2–4 hoursPlasma half-life

191 AASequence length

SQ · Daily · Evening preferred

01Mechanism of Action

Parameter

Dihexa

HGH 191AA

Primary target

c-Met receptor (HGF receptor tyrosine kinase)

Growth hormone receptor (GHR) — JAK2/STAT5 pathway

Pathway

HGF/c-Met receptor activation → downstream signaling cascade → synaptogenesis and dendritic arborization

GHR activation → JAK2/STAT5 → liver IGF-1 synthesis + direct metabolic effects

Downstream effect

Induction of dendritic arborization, synapse formation, neurogenesis, and neuroprotection in rodent models

Linear growth, lipolysis, protein synthesis, nitrogen retention, carbohydrate metabolism modulation

Feedback intact?

—

No — exogenous GH bypasses hypothalamic-pituitary axis, suppresses endogenous pulsatility

Origin

Small-molecule angiotensin IV analogue designed to activate HGF/c-Met systemWright 2015

Recombinant DNA technology — 191 AA, identical to pituitary hGH, no methionyl residue

Antibody development

—

Rare — <2% develop binding antibodies, typically non-neutralizing

02Dosage Protocols

Parameter

Dihexa

HGH 191AA

Human dosing

Not established — no human trials

—

Animal studies

Mouse/rat models only — dosing not translatable to humans

—

Evidence basis

Pre-clinical / Rodent models

FDA-approved / decades of RCT data

Clinical status

No Phase 1, 2, or 3 trials published

—

Pediatric GHD

—

0.024–0.034 mg/kg/day SQ

6–7× per week dosing typical. Brand-specific ranges.

Adult GHD

—

0.004–0.016 mg/kg/day SQ

Start low, titrate based on IGF-1 levels.

Turner syndrome

—

0.045–0.050 mg/kg/day SQ

Idiopathic short stature

—

0.037 mg/kg/day SQ

AIDS wasting

—

0.1 mg/kg/day SQ (high-dose)

Short-term indication. Monitor glucose.

Frequency

—

Once daily, typically evening

Evening administration mimics physiological GH pulse.

Monitoring

—

IGF-1, glucose, thyroid function, bone age (children)

Duration

—

Years (children until epiphyseal closure); indefinite (adult GHD)

03Metabolic / Fat Loss Evidence

Parameter

Dihexa

HGH 191AA

Primary fat target

—

Visceral and subcutaneous adipose tissue

Mechanism

—

Lipolysis via hormone-sensitive lipase activation, FFA oxidation

Effect on lean mass

—

Significant lean mass increase (protein synthesis, nitrogen retention)

Insulin sensitivity

—

Acute insulin resistance (anti-insulin effect); chronic neutral-to-improved via fat loss

IGF-1 elevation

—

Dose-dependent, significant — primary anabolic mediator

Glucose metabolism

—

Hyperglycemia risk, especially high doses (AIDS wasting)

Body composition

—

↓ fat mass, ↑ lean mass, ↑ bone mineral density (children)

Clinical context

—

FDA-approved for AIDS wasting (cachexia). Off-label use for body recomposition lacks long-term safety data.

04Side Effects & Safety

Parameter

Dihexa

HGH 191AA

Human safety data

None available — no human clinical trials

—

Theoretical c-Met risks

c-Met receptor activation has been implicated in tumorigenesis; unknown cancer risk profile

—

Pre-clinical tolerability

Not systematically reported in available studies

—

Injection site reaction

—

Lipohypertrophy, lipoatrophy, erythema (rotate sites)

Fluid retention / Edema

—

Peripheral edema, arthralgia, carpal tunnel syndrome (dose-dependent)

Glucose intolerance

—

Hyperglycemia, new-onset diabetes (anti-insulin effect)

Intracranial hypertension

—

Benign intracranial hypertension (pseudotumor cerebri) — headache, visual changes, papilledema

Slipped capital femoral epiphysis

—

SCFE risk in children — limp, hip/knee pain (requires surgery)

Scoliosis progression

—

Rapid growth may unmask/progress scoliosis (monitor spine in children)

Hypothyroidism

—

Central hypothyroidism unmasking or worsening (monitor TSH, free T4)

Cancer risk

—

Contraindicated in active malignancy. Theoretical risk in cancer survivors (controversial).

Antibody formation

—

Rare (<2%), typically non-neutralizing. Loss of efficacy if neutralizing antibodies develop.

Pancreatitis

—

Rare. Higher risk in children with certain syndromes (Prader-Willi).

Gynecomastia

—

Adolescent males (physiological during puberty, may be exacerbated)

Absolute Contraindications

Dihexa

·Not approved for human use — research compound only

HGH 191AA

·Active malignancy or history of cancer (especially childhood cancer survivors with risk factors)
·Acute critical illness (post-cardiac surgery, trauma, acute respiratory failure)
·Diabetic retinopathy (active proliferative or severe non-proliferative)
·Prader-Willi syndrome with severe obesity, sleep apnea, or respiratory impairment
·Closed epiphyses (for growth indications)

Relative Contraindications

Dihexa

·Theoretical contraindication: active or history of malignancy (c-Met pathway involvement in cancer)

HGH 191AA

·Diabetes mellitus (monitor closely, may require insulin adjustment)
·Intracranial lesions or history of intracranial hypertension
·Scoliosis (monitor curve progression)
·Untreated hypothyroidism (treat before GH initiation)
·Severe obesity (assess OSA risk, cardiovascular status)

05Administration Protocol

Parameter

Dihexa

HGH 191AA

1. Human administration

No established protocol. Dihexa has not been tested in human subjects. Animal studies used various routes (typically subcutaneous or intraperitoneal in rodents) not translatable to clinical use.

Add diluent (sterile water or bacteriostatic water per manufacturer) to vial. Swirl gently — do not shake. Solution should be clear, colorless. Concentration varies by brand (e.g., 5 mg or 10 mg per vial).

2. Legal status

Pre-clinical research compound. Not approved by FDA or any regulatory authority for human use.

Subcutaneous — rotate sites: abdomen, thigh, buttocks, upper arm. Avoid same site within 1 cm for 2 weeks to prevent lipodystrophy.

3. Timing

—

Once daily, evening preferred (6–8 PM or pre-sleep). Mimics physiological nocturnal GH secretion. Consistency is critical.

4. Storage

—

Unreconstituted: refrigerate 2–8 °C, protect from light. Reconstituted: refrigerate, use within 14–28 days (brand-specific). Do not freeze.

5. Needle

—

27–31G, 4–8 mm insulin syringe or pen device. Pinch skin, 45–90° angle depending on subcutaneous thickness.

6. Monitoring

—

Baseline and periodic: IGF-1 (target age/sex-adjusted midrange), fasting glucose, HbA1c, thyroid function (TSH, free T4), bone age (children), lipid panel. Fundoscopy if headache/visual symptoms.

06Stack Synergy

Dihexa

— no documented stacks

HGH 191AA

+ Ipamorelin

Moderate

View Ipamorelin →

Ipamorelin (GHRP) stimulates endogenous GH release, which is redundant when exogenous rhGH is administered. However, ipamorelin may still amplify pulsatility of remaining endogenous secretion in partial GHD or during GH dose titration. Not typically combined in standard clinical practice; more common in experimental or off-label protocols. Limited evidence for additive benefit.

HGH 191AA: Standard dose per indication
Ipamorelin: 100–200 mcg SQ · morning (if used)
Note: Monitor IGF-1 closely; avoid supraphysiological levels
Primary benefit: Theoretical enhancement of pulsatility; limited clinical rationale

+ Tesamorelin

Weak

View Tesamorelin →

Tesamorelin (GHRH analogue) stimulates endogenous GH secretion, which is unnecessary when exogenous rhGH is already provided. Combining both offers no mechanistic advantage and increases cost, side effects, and IGF-1 elevation risk. Not recommended in clinical practice.

Note: Combination not recommended — choose one GH modality
Primary benefit: None — redundant mechanisms