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Specimen Atlas of Research Peptides81 plates · MIT
Side-by-side · Research reference

HGH 191AAvsPancragen

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

AFDA-ApprovedHUMAN-REVIEWED0/75 cited
BAnimal-StrongHUMAN-REVIEWED23/39 cited
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
Pancragen
Bioregulatory Tetrapeptide · Khavinson School
50 μgPrimate doseGoncharova 2014
10 daysTreatment cycleGoncharova 2015
3+ weeksEffect persistenceGoncharova 2014
IM · 10-day cycleGoncharova 2014

01Mechanism of Action

Parameter
HGH 191AA
Pancragen
Primary target
Growth hormone receptor (GHR) — JAK2/STAT5 pathway
Pancreatic acinar and islet cell differentiation pathwaysKhavinson 2013
Pathway
GHR activation → JAK2/STAT5 → liver IGF-1 synthesis + direct metabolic effects
Transcription factor activation → Pdx1/Pax6/Pax4/Ptf1a/Foxa2/NKx2.2 upregulation → Cell differentiationKhavinson 2013
Downstream effect
Linear growth, lipolysis, protein synthesis, nitrogen retention, carbohydrate metabolism modulation
Enhanced pancreatic beta-cell function, normalized insulin/C-peptide dynamics, improved glucose clearanceGoncharova 2014
Feedback intact?
No — exogenous GH bypasses hypothalamic-pituitary axis, suppresses endogenous pulsatility
Yes — preserves physiological glucose-insulin response
Origin
Recombinant DNA technology — 191 AA, identical to pituitary hGH, no methionyl residue
Synthetic tetrapeptide derived from pancreatic tissue extracts (Khavinson bioregulator methodology)
Antibody development
Rare — <2% develop binding antibodies, typically non-neutralizing

02Dosage Protocols

Parameter
HGH 191AA
Pancragen
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.
Once daily for 10 daysGoncharova 2014
Evidence basis
FDA-approved / decades of RCT data
Non-human primate RCT, in vitro cell cultureGoncharova 2015Khavinson 2013
Monitoring
IGF-1, glucose, thyroid function, bone age (children)
Duration
Years (children until epiphyseal closure); indefinite (adult GHD)
Primate dose (rhesus macaque)
50 μg / animal / dayGoncharova 2014
20–25-year-old females, 10-day IM protocol.
Effective concentration (in vitro)
0.05 ng/mLZakutskiĭ 2006
Organotypic tissue culture, both young and aged rat explants.
Route
IntramuscularGoncharova 2015
Treatment cycle
10-day course, effects persist 3+ weeks post-withdrawalGoncharova 2014
Diabetes model
STZ-induced diabetes (rat)
Evaluated via metabolic markers characterizing apoptosis.

03Metabolic / Fat Loss Evidence

Parameter
HGH 191AA
Pancragen
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
HGH 191AA
Pancragen
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)
Reported adverse events
None documented in primate studies
Tolerability
Well-tolerated in aged rhesus monkeys (n=9)Goncharova 2015
Human safety data
No published human trials; clinical use limited to Russian gerontology protocols
Absolute Contraindications
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)
Pancragen
Relative Contraindications
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)
Pancragen
  • ·Active pancreatic malignancy (proliferation marker upregulation)

05Administration Protocol

Parameter
HGH 191AA
Pancragen
1. Reconstitution (if lyophilized)
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).
Lyophilised tetrapeptide reconstituted in sterile saline or water per manufacturer protocol. Concentration not specified in literature.
2. Injection site
Subcutaneous — rotate sites: abdomen, thigh, buttocks, upper arm. Avoid same site within 1 cm for 2 weeks to prevent lipodystrophy.
Intramuscular injection. Primate studies used daily IM dosing for 10 consecutive days.Goncharova 2015
3. Timing
Once daily, evening preferred (6–8 PM or pre-sleep). Mimics physiological nocturnal GH secretion. Consistency is critical.
No specific timing constraints documented. Administered once daily in primate protocols.
4. Storage
Unreconstituted: refrigerate 2–8 °C, protect from light. Reconstituted: refrigerate, use within 14–28 days (brand-specific). Do not freeze.
10-day treatment course. Restorative effects on pancreatic function persist for at least 3 weeks post-discontinuation.Goncharova 2014
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

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
Pancragen
— no documented stacks