Quick Comparison
| HGH 191AA | Livagen | |
|---|---|---|
| Half-Life | 2-3 hours | Approximately 30 minutes (acute pharmacology); proposed gene-expression effects outlast plasma exposure |
| Typical Dosage | Clinical (GH deficiency): 0.2-0.6 mg subcutaneous once daily. Anti-aging: 1-2 IU subcutaneous once daily, typically before bed. Bodybuilding: 2-4 IU subcutaneous once daily (up to 6-8 IU in advanced protocols). All doses injected subcutaneously, preferably in the evening to coincide with natural GH pulse timing. | Oral (capsule): 100-200 mg once daily for 10-30 day cycles, repeated 2-3 times per year. Subcutaneous injection: 1-5 mg per dose, alternate days for 10-20 day cycles. Standard Khavinson cycling rather than continuous use. |
| Administration | Subcutaneous or intramuscular injection (daily) | Oral capsule or subcutaneous injection (cycled) |
| Research Papers | 0 papers | 5 papers |
| Categories |
Mechanism of Action
HGH 191AA
Human Growth Hormone is a 191-amino-acid single-chain polypeptide secreted by somatotroph cells of the anterior pituitary gland. It exerts its effects through two distinct pathways: direct action via GH receptors and indirect action through insulin-like growth factor 1 (IGF-1). When HGH binds to the GH receptor (a type I cytokine receptor), it induces receptor dimerization and activates the JAK2/STAT5 signaling cascade, which directly stimulates gene transcription for protein synthesis, cell proliferation, and lipolysis.
The indirect pathway is equally important. GH receptor activation in hepatocytes stimulates the production and secretion of IGF-1, a 70-amino-acid peptide that circulates bound to IGF binding proteins (primarily IGFBP-3 and the acid-labile subunit). Circulating IGF-1 acts on virtually every tissue in the body — promoting amino acid uptake and protein synthesis in skeletal muscle, stimulating chondrocyte proliferation in growth plates, enhancing osteoblast activity for bone formation, and supporting neuronal survival and myelination.
GH also has profound effects on metabolism independent of IGF-1. It directly stimulates lipolysis in adipocytes by activating hormone-sensitive lipase, mobilizing stored fat as free fatty acids for energy. It antagonizes insulin action in peripheral tissues (hence the diabetogenic risk), shifting the body's fuel preference from glucose to fatty acids. In muscle, GH promotes nitrogen retention and positive protein balance. The pulsatile pattern of natural GH secretion — with the largest pulse during deep sleep — is important for its physiological effects, which is why exogenous GH protocols often try to mimic this pattern.
Livagen
Livagen is a short tripeptide (Lys-Glu-Asp) within the Khavinson bioregulator family — peptides hypothesised to regulate gene expression in tissue-specific ways by binding to gene promoter regions. Livagen is positioned as the liver-targeted member of this family, intended to modulate hepatocyte gene expression in ways that support liver regeneration and counteract age-related decline in hepatic function.
Proposed mechanisms include modulation of chromatin condensation states in hepatocyte and lymphocyte nuclei, upregulation of genes involved in hepatic detoxification pathways (cytochrome P450 enzymes, glutathione synthesis), and immunomodulatory effects in liver-resident immune cells. Russian research has reported livagen-induced increases in hepatocyte regeneration markers in animal models of liver injury and changes in lymphocyte chromatin organisation consistent with cellular rejuvenation.
As with all Khavinson tripeptides, the proposed action model is that livagen acts as a transient signalling molecule triggering longer-lasting changes in gene expression. Plasma exposure is brief (around 30 minutes) but downstream transcriptional effects are claimed to persist for weeks, justifying pulse-dosing protocols of 10-30 day courses repeated periodically. The evidence base for clinical efficacy is dominated by Russian gerontology research with limited independent Western replication, and clinical use outside Russia remains largely anecdotal. Livagen should not be used as a substitute for evidence-based liver disease management.
Risks & Safety
HGH 191AA
Common
joint pain, wrist pain/numbness (carpal tunnel), water retention and swelling, headache, tingling in hands/feet.
Serious
can make your body less responsive to insulin (raising blood sugar), may accelerate growth of existing tumours, enlarged jaw/hands/feet with long-term overuse.
Rare
increased pressure in the skull, breast tissue growth in men, underactive thyroid. Not suitable for people with active cancer or severe illness.
Livagen
Common
generally reported as well tolerated.
Serious
very limited Western clinical data; long-term safety in the context of pre-existing liver disease is not established.
Rare
allergic reactions. Like other Khavinson bioregulators, the evidence base is significantly thinner than the marketing suggests.
Full Profiles
HGH 191AA →
Synthetic human growth hormone, identical to what your body naturally produces. FDA-approved for growth hormone deficiency and sold under brand names like Norditropin and Genotropin. Widely used in anti-aging medicine and bodybuilding because it helps build muscle, burn fat, speed up recovery, and improve skin and sleep quality. One of the most well-studied performance peptides available.
Livagen →
A Khavinson tripeptide (Lys-Glu-Asp) developed in Russia as a tissue-specific bioregulator targeting the liver. Promoted for supporting liver regeneration, age-related liver decline, and as part of broader anti-ageing protocols. Sits in the same family as epithalon (pineal), cortagen (brain), and pinealon (pineal/brain). Most evidence is from Russian preclinical work — rigorous Western clinical trials are essentially nonexistent.