Does Titan sell LL-37?

No — LL-37 is not a Titan catalog product. Titan's RUO line centers on in-house-tested research peptides such as BPC-157, TB-500, retatrutide, the CJC-1295 + Ipamorelin blend, and pre-mixed nasal-format peptides. Rather than list a 37-residue cationic peptide it does not verify in-house, Titan points researchers to what it does stock and to the COA standard that applies to any research compound.

Why does 'net peptide content' matter when buying LL-37?

LL-37 is highly cationic, so it is isolated as a salt — the counterion (often trifluoroacetate or acetate) plus bound water can make up a real fraction of the vial's weight. Net peptide content is the figure that subtracts the salt and water to state how much actual peptide you received, which can be meaningfully less than the labelled milligrams. A COA that reports only purity and a gross weight leaves this out. This is a verification and quantity point, not a claim about any effect.

What should a real LL-37 COA show?

A credible lot-matched certificate should confirm identity as the full-length 37-mer (HPLC chromatogram shown plus accurate-mass MS, since a long chain carries deletion-sequence risk), resolve purity from that chromatogram rather than a bare figure, state net peptide content and the salt/counterion form, note water content, and carry a lot number that matches the code on the unit you receive. A generic 'third-party tested, 99% pure' badge with none of that is not verification for a long, cationic peptide.

Is LL-37 for human use?

No. Anything discussed here is strictly for in-vitro laboratory research. LL-37 supplied as a research chemical is not for human or animal consumption, and no antimicrobial, wound, immune, dosing, or any other outcome is claimed for it. Nothing on this page is a dosing schedule or a human-use protocol — it is a sourcing and verification guide only.

Where to buy LL-37 (cathelicidin) · research sourcing & COA

Where to buy LL-37 for research — and why its release sheet has to prove length and net peptide content.

LL-37 is the most-studied human antimicrobial peptide, the C-terminal fragment of cathelicidin hCAP18, and demand for it as a research material has drawn a field of sellers whose evidence rarely goes past a '99% pure' line and a generic 'third-party tested' badge. The problem is that LL-37 is a very different sourcing proposition than a short peptide. It is 37 residues long and unusually cationic — packed with arginine and lysine — and those two facts change which questions actually matter. At 37 residues, a synthesis is far more likely to carry deletion sequences (a chain missing one amino acid) than a five- or six-mer, so full-length identity has to be proven, not assumed. And because the molecule is so basic, it is isolated as a salt whose counterion can make up a real fraction of the vial's weight — which means net peptide content, not gross milligrams, is what you actually received. This page is written for researchers sourcing LL-37 for laboratory use: what a real lot-matched COA should prove, why net peptide content and full-length verification are the questions bargain sellers skip, and where Titan's honest catalog fits. It is for in-vitro laboratory and research use only (RUO). No human-use, antimicrobial, dosing, or any other outcome is claimed anywhere on this page.

See what Titan actually stocks How to verify a COA

LL-37 is a 37-residue cationic cathelicidin

LL-37 takes its name from its first two residues (Leu-Leu) and its length — 37 amino acids, the C-terminal antimicrobial fragment of the cathelicidin precursor hCAP18. It is amphipathic and heavily cationic, carrying many arginine and lysine residues, which is what gives the molecule its character. That length and charge are the two properties that decide how it should be verified: a long chain raises the odds of synthesis deletions, and a highly basic peptide is handled as a salt. Neither is captured by a purity percentage on its own, so the first job of a real release sheet is to establish that the full 37-mer is present and how much of the vial is actually peptide.

How to read a COA →

Net peptide content, not gross milligrams

Because LL-37 is so cationic, it is isolated as a salt — typically with a trifluoroacetate or acetate counterion left over from purification — and that counterion plus bound water can account for a meaningful share of the vial's weight. A label that says '5 mg' may contain noticeably less than 5 mg of actual peptide once the salt and water are subtracted. That figure is called net peptide content, and it is the number a serious buyer wants stated on the COA. A certificate that reports only purity and a gross weight is quietly leaving out how much LL-37 you truly received.

Current-lot COA checklist →

At 37 residues, deletion sequences are the real risk

The longer the chain, the more chances a synthesis has to drop a single residue and produce a deletion sequence — a 36-mer that is one amino acid short of real LL-37. These impostors can sit close to the target on a purity trace and slip past a certificate that reports one purity peak without an identity mass. That is why a credible LL-37 release sheet shows the accurate-mass MS confirming the full-length molecule alongside the HPLC chromatogram, rather than assuming a single high peak equals the correct sequence. Length is precisely why identity verification matters more here than on a short peptide.

What COA-verified means →

LL-37 is not BPC-157 or TB-500 — a common basket mix-up

LL-37 often gets thrown into the same 'research peptide' basket as repair-associated compounds like BPC-157 or TB-500, but it is a different kind of molecule with different verification needs. LL-37 is a long, heavily cationic antimicrobial peptide where net peptide content and full-length identity dominate; the shorter compounds Titan stocks are checked as their own distinct sequences with their own concerns. Grouping them under one 'tested' badge misses that each has a specific question a real COA has to answer — and LL-37's questions are length and salt form.

Where to buy BPC-157 (in stock) →

Why generic 'tested' badges fail on LL-37

A one-size-fits-all 'third-party tested, 99% pure' stamp is designed for a simple, short peptide where a purity number carries the weight. LL-37 breaks that model twice over — its length demands full-length identity confirmation, and its charge demands a net-peptide-content figure — and a recycled badge mentions neither. A vendor that reuses the same stamp it prints for every SKU is signalling it has not thought about what a 37-residue cationic peptide requires. The right response is to ask for the chromatogram, the accurate-mass identity data, and the net peptide content, and to walk if all they can produce is a certificate with a different product name on top.

Supplier checklist →

What Titan actually stocks (honest)

Titan does not stock LL-37. Titan's RUO catalog is a focused set of in-house-tested research peptides — BPC-157, TB-500, retatrutide, the CJC-1295 + Ipamorelin blend, and a line of pre-mixed nasal-format peptides — not every compound the internet files under 'antimicrobial' or 'immune' research. Rather than list a 37-residue cationic peptide it does not verify in-house, Titan points researchers to what it does test and to the verification standard that applies to any research material, LL-37 included. The links here cover the honest sourcing context and the in-catalog options.

Best research peptides (in stock) →

The detail, in plain terms

LL-37 sourcing, in plain terms.

LL-37 is a 37-residue, heavily cationic cathelicidin peptide. Its length makes full-length identity the first thing to prove, and its charge makes net peptide content the number that tells you how much peptide is really in the vial. Confirm both — accurate-mass MS for the full 37-mer with the chromatogram shown, and a stated net-peptide-content figure — before you trust a purity percentage.

What it is: A 37-residue amphipathic, cationic antimicrobial peptide — the C-terminal fragment of cathelicidin hCAP18.
First question: Is the full 37-mer present? Long chains carry deletion-sequence risk a purity peak alone can miss.
Second question: Net peptide content — the counterion salt and water reduce how much of the labelled weight is peptide.
Identity check: HPLC chromatogram shown + accurate-mass MS confirming the full-length molecule.
Also confirm: Salt/counterion form, water content, and a lot number matching the code on the unit received.
Titan stocks: Not a SKU — honest redirect to in-stock, in-house-tested research peptides.

Questions researchers ask

Before you order.

Does Titan sell LL-37?: No — LL-37 is not a Titan catalog product. Titan's RUO line centers on in-house-tested research peptides such as BPC-157, TB-500, retatrutide, the CJC-1295 + Ipamorelin blend, and pre-mixed nasal-format peptides. Rather than list a 37-residue cationic peptide it does not verify in-house, Titan points researchers to what it does stock and to the COA standard that applies to any research compound.
Why does 'net peptide content' matter when buying LL-37?: LL-37 is highly cationic, so it is isolated as a salt — the counterion (often trifluoroacetate or acetate) plus bound water can make up a real fraction of the vial's weight. Net peptide content is the figure that subtracts the salt and water to state how much actual peptide you received, which can be meaningfully less than the labelled milligrams. A COA that reports only purity and a gross weight leaves this out. This is a verification and quantity point, not a claim about any effect.
What should a real LL-37 COA show?: A credible lot-matched certificate should confirm identity as the full-length 37-mer (HPLC chromatogram shown plus accurate-mass MS, since a long chain carries deletion-sequence risk), resolve purity from that chromatogram rather than a bare figure, state net peptide content and the salt/counterion form, note water content, and carry a lot number that matches the code on the unit you receive. A generic 'third-party tested, 99% pure' badge with none of that is not verification for a long, cationic peptide.
Is LL-37 the same kind of compound as BPC-157 or TB-500?: No. LL-37 is a long (37-residue), heavily cationic antimicrobial peptide whose verification is dominated by full-length identity and net peptide content. BPC-157 and TB-500 are different, and are checked as their own distinct sequences with their own concerns. They often land in the same 'research peptide' basket, but a single 'tested' badge cannot answer the specific question each one raises — LL-37's questions are length and salt form.
Is LL-37 for human use?: No. Anything discussed here is strictly for in-vitro laboratory research. LL-37 supplied as a research chemical is not for human or animal consumption, and no antimicrobial, wound, immune, dosing, or any other outcome is claimed for it. Nothing on this page is a dosing schedule or a human-use protocol — it is a sourcing and verification guide only.