Render5 mg vial · front

Gastric & thymosin peptides

TB-500

The N-acetylated 17–23 fragment of thymosin β4 (Ac-LKKTETQ), the compound anti-doping laboratories identified in products sold as TB-500.

Also known as Ac-LKKTETQ

Formula: C₃₈H₆₈N₁₀O₁₄
Average mass: 889.005 Da
Length: 7 residues

Lot Record

Sealed, crimp-capped vial with its lot number on the label.
Orders are packed once payment clears.

Research use only. TB-500 is supplied as a laboratory reagent. It is not a drug, food, supplement or cosmetic, and it is not for human or veterinary use.

Lot record

Check the lot before you buy.

Purity is the main peak’s share of the HPLC signal. Identity is the mass the sequence predicts, next to the mass measured. Move along either trace to read it.

Certificate of analysis

Loading the lot record

HPLC purity
Release minimum: 99.0%
Mass, calculated: 889.005 Da
Mass, observed
Difference: release rule: within ±1.0 Da
Tested
Laboratory
Method

How to read a certificate

HPLC RP · UV 220 nm

The chromatogram draws here from the lot’s numbers.

Mass spec ESI, positive

The mass spectrum draws here from the sequence and the lot’s numbers.

Every published lot

Published lots of TB-500
Lot	Tested	HPLC purity	Observed mass, Da	Status	Certificate

Overview

What it is.

Thymosin β4 is a 43-residue actin-binding protein. TB-500 is a synthetic, N-acetylated copy of its residues 17–23, the stretch that contains its actin-binding motif. Anti-doping laboratories identified this fragment as the content of products sold under the TB-500 name; some suppliers use the same name for full-length thymosin β4, which is a different molecule.

Research on the fragment includes cell studies of migration and proliferation and analytical work on detecting it and its metabolites. Most published biology concerns full-length thymosin β4 rather than this fragment.

We don’t summarize studies on product pages. Search PubMed for “TB-500” (opens in a new tab)

Sequence & properties

Computed from the sequence.

L1K2K3T4E5 T6Q7

Residue colors: Hydrophobic Polar Basic (+) Acidic (−) Non-standard

Three-letter sequence: Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-OH

Open in Sequence Studio

Molecular formula: C₃₈H₆₈N₁₀O₁₄
Average mass: 889.005 Da
Monoisotopic mass: 888.4916 Da
Length: 7 residues
Isoelectric point (pI): 7.36
Net charge at pH 7.0: 0.00
GRAVY (Kyte–Doolittle): −1.771
Extinction coefficient, 280 nm: No Trp or Tyr: measure at 205–220 nm
Modifications: N-terminal acetylation
Form: Lyophilized powder in a sealed glass vial
Purity: Measured per lot by HPLC: see the lot record

Calculated from the sequence with standard atomic weights and the EMBOSS pKa set, for the free peptide (not a salt form). The formula matches a chemical supplier’s datasheet (opens in a new tab); the mass agrees with it to within 0.05 Da.

HydropathyKyte–Doolittle · window 5

Above zero is hydrophobic; below is polar or charged. No window averages above zero. Least polar: residues 1–5 (average −1.6); most polar: residues 2–6 (average −2.5).

Storage & handling

Cold, dry and dark.

Sealed vial: Follow the released lot’s documented storage conditions and laboratory safety data.
In transit: Transport conditions must be supported for this material; ambient shipping is not assumed.
Before opening: Let the vial reach room temperature, so moisture doesn’t condense on the powder.
In solution: Use a validated in-vitro laboratory protocol. Stability depends on the compound, solvent and conditions; no general shelf life is promised.

Solution Calculator Storage and handling guide

Questions

Before you order.

All questions

How do I know what’s in the vial?

Every lot we sell has a certificate of analysis on file, showing HPLC purity and mass-spectrometry identity for that exact lot. It is linked on the product page before you buy.

The lot number printed on your vial opens the same record on our Verify page, so you can match the vial in your hand to its test results.

What does an HPLC purity figure tell me?

High-performance liquid chromatography separates a sample into its components. Purity is the main peak’s share of the total detected signal, usually measured by UV absorbance around 214–220 nm.

It measures the main component against peptide-related impurities; it isn’t net peptide content, which also accounts for water and counter-ions.

What HPLC purity means

How do I pay, and when does my order ship?

The available payment methods are listed at checkout. A research request first enters review, with no payment due. Payment instructions appear only after verification and approval. Sample requests cannot be paid or fulfilled.

Orders are packed once payment clears. You can follow every step on the order page or with your order number on Track an order.

What does “research use only” mean?

Our peptides are supplied as laboratory reagents for research by qualified buyers. None is approved as a drug, food, supplement or cosmetic in the form we supply it, and none is for human or veterinary use.

We don’t give advice about using peptides in people or animals, and product pages describe what each compound is and how it is studied, never what it does to a person.