Immune

Peptides that modulate immune and inflammatory signalling — including agents approved in specific countries and indications, alongside preclinical-stage molecules with promising models behind them.

Community-reported ranges are anecdotal and not clinically validated. Evidence grade shown reflects the strength of available human data. Not a prescription. Legal status varies by country and changes over time; verify locally.

5 peptides

Thymosin Alpha-1

Human RCT

Tα1, Zadaxin

An immunomodulatory peptide approved in several countries (e.g. as Zadaxin) for hepatitis and as a vaccine adjuvant. Approval status varies by region.

KPV

Animal / preclinical

Lysine-Proline-Valine

The anti-inflammatory business end of alpha-MSH, distilled to three amino acids. In cell and animal models — particularly colitis models — it damps inflammatory signalling, which is why gut-health protocols have adopted it; human trials are still to come.

LL-37

Animal / preclinical

Cathelicidin fragment

The body's own front-line antimicrobial peptide, with a large research literature on host defence and wound healing. Its biology is genuinely double-edged (context-dependent pro- and anti-inflammatory roles), and injectable product use runs ahead of the human trial base.

VIP (Vasoactive Intestinal Peptide)

Human observational

Aviptadil, Vasoactive Intestinal Polypeptide

A signalling peptide with broad anti-inflammatory and vasodilatory roles. Its synthetic form (aviptadil) has been investigated for lung conditions; intranasal VIP appears in off-label chronic-inflammatory (CIRS) protocols with limited formal evidence.

Thymalin

Human observational

Thymus peptide extract

A thymus-derived peptide preparation used clinically in Russia and some neighbouring countries as an immunomodulator. Independent evidence outside that setting is limited.