Immune Peptides

Thymalfasin (trade name Zadaxin)

Thymosin Alpha-1 (trade name Zadaxin / Thymalfasin) is a 28 amino acid acetylated peptide corresponding to the N-terminus of prothymosin alpha. It is approved in more than 35 countries for hepatitis B and C treatment and as an immune adjuvant for vaccines and certain cancers, but is NOT FDA-approved in the US — Phase 3 HCV trials ended without approval. Research focuses on TLR2/TLR9-driven dendritic cell activation, T-cell maturation, NK cytotoxicity, and cytokine balancing of innate and adaptive immune responses. The Zadaxin label dose is 1.6mg SubQ twice weekly; grey-market research protocols often use 1.6–3.2mg SubQ 2x/week in 4–8 week cycles. Researchers track WBC, CD4/CD8 ratio, NK cells, and immunoglobulin panels (IgG, IgA, IgM) as primary response biomarkers. US regulatory status: was on FDA 503A interim Category 1 bulks list, moved to Category 2 in 2023, nominator withdrew in September 2024, and on December 4, 2024 the FDA Pharmacy Compounding Advisory Committee voted AGAINST inclusion on the 503A Bulks List.

Cathelicidin

LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide (starting with two leucines) cleaved from the hCAP-18 precursor. It has broad-spectrum antimicrobial activity and immunomodulatory roles, but is also implicated in the pathogenesis of autoimmune and inflammatory skin diseases including psoriasis, rosacea, and lupus. Not FDA-approved; research-use only.

VIP

Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide of the secretin/glucagon family, widely distributed in the CNS and peripheral nervous system. It is a potent vasodilator, bronchodilator, and immunomodulator. Synthetic VIP (aviptadil) has been investigated in clinical trials for COVID-19-associated acute respiratory failure; it is NOT FDA-approved. Intranasal compounded VIP is used off-label in the controversial 'CIRS' (Chronic Inflammatory Response Syndrome) / mold-illness protocol popularized by Ritchie Shoemaker — CIRS is not a mainstream medical diagnosis.

Facteur Thymique Serique (FTS)

Thymulin is a zinc-dependent nonapeptide (pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn) secreted by thymic epithelial cells, originally isolated by Bach and colleagues in the 1970s as 'facteur thymique sérique' (FTS). It is NOT the same compound as Thymalin (a Russian bovine thymus extract) or Thymosin alpha-1 (a separate 28-amino-acid thymic peptide). Thymulin is not FDA-approved; use is research/investigational only.

GSH

Glutathione is an endogenous tripeptide (gamma-L-glutamyl-L-cysteinyl-glycine) that serves as the principal intracellular antioxidant in mammalian cells. It is not FDA-approved as a drug in the US; parenteral glutathione is used off-label (and in some compounding settings) for oxidative stress, hepatic support, and — controversially — skin lightening. The FDA has warned against injectable glutathione for skin lightening (2019) due to reports of serious adverse events.

Gut Matrix

Enteric-coated oral capsule blend of palmitoylethanolamide (PEA), BPC-157 arginate, KPV, and N-acetyl larazotide, marketed for gut-barrier / GI support. A vendor-formulated combination; not clinically validated as a blend. Evidence is component-level only.

PNC27

An experimental p53-derived peptide studied for selective membrane disruption of cancer cells. Strictly preclinical; no approved or validated human use.

Bronchogen

A short synthetic peptide bioregulator (Ala-Asp-Glu-Leu) from the Khavinson family, marketed for bronchial/respiratory tissue support. Evidence is largely Russian-language and preclinical.

Chonluten

A short synthetic peptide bioregulator (Glu-Asp-Gly) from the Khavinson family, marketed for bronchial/lung epithelium support. Evidence is largely Russian-language and preclinical.

thymalinum

Thymalin is a heterogeneous polypeptide extract from calf thymus (a mixture, not a single defined peptide) developed in the 1970s by V. Kh. Khavinson and V. G. Morozov at the Military Medical Academy / St. Petersburg Institute of Bioregulation and Gerontology. Registered as a pharmaceutical in the USSR/Russia for immunocorrection. Distinct from Thymulin (Bach's zinc-dependent nonapeptide pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, originally called FTS) and from Thymosin alpha-1 (a 28-amino-acid synthetic peptide). Not FDA-approved in the US; research-use only.

Thymagen

Thymogen (also marketed as Thymagen) is a synthetic dipeptide, L-Glu-L-Trp (Glu-Trp), originally isolated by the Khavinson group from the calf-thymus polypeptide complex Thymalin and then synthesized. It is registered as a pharmaceutical in Russia for immunocorrection (nasal drops / IM injection). Not FDA-approved in the US; research-use only.

Lys-Glu-Asp-Ala

Livagen is a synthetic tetrapeptide (Lys-Glu-Asp-Ala / KEDA) from the Khavinson short-peptide 'bioregulator' series, developed at the St. Petersburg Institute of Bioregulation and Gerontology. Marketed in Russia primarily as a food-supplement-grade cytomax; not FDA-approved in the US; research-use only.

Lys-Glu

Vilon is a synthetic dipeptide (Lys-Glu / KE) from the Khavinson bioregulator series, originally derived from thymus extracts and studied in Russian preclinical models as an immunomodulator and geroprotector. Not FDA-approved; all published evidence originates from a single research group.

ta1thymalin

Vendor 'TA-1 Complex' blend combining Thymosin Alpha-1 (Zadaxin; approved in some countries for hepatitis B/C, not FDA-approved in the US) with Thymalin (a Russian calf-thymus polypeptide extract associated with the Khavinson research program). This blend is not clinically validated; no trials have studied the combination itself.