Disclosure: We earn a commission from vendors on this page. Rankings are based on price, COA availability, and reputation.

Best Immune Peptides (2026)

Immune peptides strengthen your body's defense systems — from T-cell activation to antimicrobial action. Here are the best vendors for each.

At a Glance

1

Gold standard immune peptide. FDA orphan drug for hepatitis B. Activates T-cells and dendritic cells. Well-tolerated even long-term.

Gold standard immune peptide. FDA orphan drug for hepatitis B. Activates T-cells and dendritic cells. Well-tolerated even long-term.

VendorPriceAmount$/mgCOA
EZ Peptides$58.0010mg$5.80/mgYesBuy →
Ascension Peptides$75.0010mg$7.50/mgYesBuy →
Ion Peptide$42.005mg$8.40/mgYesBuy →
See all Thymosin Alpha-1 vendors →
2
KPV3 vendors

Potent anti-inflammatory tripeptide derived from alpha-MSH. Strong gut and skin inflammation data. Very few side effects.

Potent anti-inflammatory tripeptide derived from alpha-MSH. Strong gut and skin inflammation data. Very few side effects.

VendorPriceAmount$/mgCOA
EZ Peptides$38.0010mg$3.80/mgYesBuy →
Ascension Peptides$79.9910mg$8.00/mgYesBuy →
Ion Peptide$49.0010mg$4.90/mgYesBuy →
See all KPV vendors →
3
LL-373 vendors

Natural antimicrobial peptide — kills bacteria, viruses, and fungi directly. Also modulates immune response.

Natural antimicrobial peptide — kills bacteria, viruses, and fungi directly. Also modulates immune response.

VendorPriceAmount$/mgCOA
Ion Peptide$45.005mg$9.00/mgYesBuy →
BioLongevity Labs$94.975mg$18.99/mgYesBuy →
Swiss Chems$71.995mg$14.40/mgYesBuy →
See all LL-37 vendors →
4
Thymulin2 vendors

Thymus hormone that matures T-cells. Age-related decline makes supplementation logical but limited modern research.

Thymus hormone that matures T-cells. Age-related decline makes supplementation logical but limited modern research.

VendorPriceAmount$/mgCOA
BioLongevity Labs$64.9710mg$6.50/mgYesBuy →
Limitless Biotech$19.9910mg$2.00/mgYesBuy →
5
VIP3 vendors

Vasoactive intestinal peptide — broad anti-inflammatory. Used in CIRS/mold illness protocols. Complex dosing.

Vasoactive intestinal peptide — broad anti-inflammatory. Used in CIRS/mold illness protocols. Complex dosing.

VendorPriceAmount$/mgCOA
Ion Peptide$79.0010mg$7.90/mgYesBuy →
BioLongevity Labs$74.975mg$14.99/mgYesBuy →
Royal Peptides$465.0010mg$46.50/mgYesBuy →
See all VIP vendors →

How We Rank Vendors

Every vendor is scored on three factors: price per mg (40%), third-party COA testing (30%), and community reputation (30%). Scores floor at 8.0 — if a vendor is on our site, they are worth buying from.

Price (40%)

Normalized to $/mg for fair comparison across vial sizes.

COA Testing (30%)

Third-party lab results confirming purity and identity.

Reputation (30%)

Community feedback, shipping reliability, and track record.