LL-37 vs Thymosin Alpha-1
Which should you choose? Here's what you need to know.
The short answer
LL-37 and Thymosin Alpha-1 are both immune / inflammation peptides, but they work differently. The only human cathelicidin antimicrobial peptide. Plays a key role in innate immune defense against bacterial, viral, and fungal infections. A thymic peptide that modulates immune function. FDA-orphan drug approved and used clinically in many countries for immune support. Compare vendor pricing and availability below.
On 20 Sep 2026 Peptide Compare tracked 39 vendors selling LL-37, cheapest in stock $5.40 per mg at Alpha Omega, and 37 selling Thymosin Alpha-1, cheapest $3.85 per mg at Step One.
LL-37
Immune / InflammationThe only human cathelicidin antimicrobial peptide. Plays a key role in innate immune defense against bacterial, viral, and fungal infections.
Thymosin Alpha-1
Immune / InflammationA thymic peptide that modulates immune function. FDA-orphan drug approved and used clinically in many countries for immune support.
Price & availability
Once you've decided which peptide fits your needs, here's how they compare on price and vendor options. Prices verified Sep 20, 2026.
LL-37
Thymosin Alpha-1
$34.99
Starting from
$37.00
$17.22
Avg. price per mg
$8.69
39
Vendors selling it
37
38 options
In stock now
38 options
9.0/10
Top trust score
9.0/10
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Where does this data come from?
We re-check vendor prices continuously and score vendors on Finnrick blind-test results — samples bought anonymously and sent to a lab, not vendor claims. No vendor can pay to rank higher. See our full methodology.