HGH 191AA (Somatropin) Dosage Protocols: All Vial Sizes
HGH 191AA is recombinant human growth hormone — a 191-amino-acid polypeptide identical to endogenous pituitary GH. Used clinically for growth-hormone deficiency and studied for body composition, recovery, and aging. Choose your vial size below; each size has its own exact dosing table.
Choose Your Vial Size
| Vial | Final volume | Concentration | One U-100 unit | |
|---|---|---|---|---|
| 24 IU | 3 mL | 8 IU/mL | 0.08 IU in 0.01 mL | Open protocol → |
| 36 IU | 3 mL | 12 IU/mL | 0.12 IU in 0.01 mL | Open protocol → |
| 50 IU | 3 mL | 16.67 IU/mL | 0.1667 IU in 0.01 mL | Open protocol → |
Doses are the same research amounts across sizes; the vial size changes the concentration, so syringe units differ. Always use the table for your exact vial.
Storage Instructions
| State | Temperature | Duration |
|---|---|---|
| Lyophilized | −20°C (−4°F) | Up to 24 months, dry & dark |
| Reconstituted | 2–8°C (35–46°F) | Up to 14 days, protect from light |
Important Notes
How This Works
HGH 191AA is a 191-amino-acid recombinant peptide identical in sequence to native human pituitary GH (somatropin). After subcutaneous injection, GH binds the dimeric GH receptor on hepatocytes, adipocytes, myocytes, and chondrocytes. Receptor activation triggers JAK2/STAT5 signaling that drives IGF-1 production from the liver — IGF-1 mediates most of GH's anabolic effects.
Native GH release is pulsatile with the largest pulse during slow-wave sleep. Exogenous somatropin produces a single steady-state pulse per dose. Many protocols favor evening dosing to roughly approximate the natural overnight pulse.
Potential Benefits & Side Effects
Potential Benefits
- Reductions in adipose tissue, particularly visceral fat.
- Increases in lean body mass over 6–12 months.
- Improved exercise capacity and recovery in some studies.
- Improved skin thickness and dermal collagen content.
- Restoration of normal IGF-1 in deficiency states.
Side Effect Profile
- Fluid retention — peripheral edema, hands and feet.
- Joint pain and stiffness.
- Carpal tunnel syndrome.
- Insulin resistance and elevated fasting glucose at higher doses.
- Headache; rare intracranial pressure changes.
- Theoretical concerns with active malignancy.
Lifestyle Factors
- Evening dosing aligns with natural overnight GH pulse.
- Avoid eating for 1–2 hours after injection — insulin blunts GH efficacy.
- Resistance training amplifies anabolic effects.
- Aerobic exercise improves insulin sensitivity, offsetting glucose intolerance.
- Sleep 7–9 hours — most natural GH/IGF-1 work occurs in slow-wave sleep.
Injection Technique
- Subcutaneous into abdomen, thigh, or upper arm. Rotate sites daily.
- 90° angle with short (4–8 mm) insulin needle.
- Bring vial to room temperature 15 min before injecting.
- Reconstituted GH is fragile — swirl gently, do not shake.