Family G · 4 guides

Immune peptides

Arkham Labs editorial/Published 8 September 2026/Revised 12 September 2026/Corrections policy

Thymic peptides and antimicrobial host-defence peptides. The family contains the best-evidenced compound in the library and three with no trial of the administered peptide at all, which makes it the sharpest illustration of why a family label is not a quality signal.

State of the evidence

The largest trial in this family was negative, and it was not close.

Thymosin alpha-1‘s biggest double-blind placebo-controlled trial enrolled 508 patients with severe acute necrotising pancreatitis. Infected pancreatic necrosis occurred in 15.7% against 18.1%; the difference was −2.4% (95% CI −7.4 to 5.1), p = 0.48. The guide carries Mixed Evidence because the wider randomised record conflicts by trial design, not because that trial is in dispute. LL-37 is documented as cytotoxic to human cells, including osteoblasts, and as causing rapid transient disruption of the human colonic barrier. KPV‘s receptor mechanism was an open question in 2004 and remains one. Thymulin is biologically active only when coupled to zinc.

Guides in this family
4
Peer-reviewed sources
76
Grades represented
Preclinical 3 · Mixed 1
3 preclinical1 mixed evidence

Thymosin alpha-1 has extensive randomised human data and still grades Mixed Evidence, because more trials has not meant more agreement.

Standing notice

For laboratory research use only. Not for human consumption. Nothing here is medical advice.