TB-500 pen: what it is, what it costs and where to buy it

The TB-500 pen is a pre-filled pen injector whose sealed cartridge already holds TB-500 in solution. AuraVia Research sells it under the name TB-500 Pen: 10 mg of TB-500 in 3 ml of solution. The design comes from insulin pens: a plastic body, a cartridge, a cap and a graduated dial mechanism. Unlike a vial of freeze-dried powder, there is nothing to reconstitute before an experiment.

The vendor's product page lists the following specifications:

The dial is part of the pen's mechanism, as on insulin pens. This page does not explain how to use it, because TB-500 is not an approved medicine and we give no usage advice. TB-500 itself is a synthetic peptide related to thymosin beta-4: it reproduces the active region of the protein, built around the LKKTETQ sequence (Sosne et al., 2010). The pen does not change the compound. It only changes the form in which it is stored and sold.

AuraVia Research sells TB-500 in two formats with the same amount, 10 mg, which makes the comparison direct. Prices checked on October 19, 2026, VAT included.

At list price, the pen costs 43% more than the vial. This is the smallest pen-to-vial gap in AuraVia's range, where the gap goes from 43% to 125% depending on the compound (see our comparison of pre-filled peptide pens and vials). With the vial's current promotion, the gap grows to about 67%. These prices change often: check the current price on the vendor's site before you order.

Price is not the only difference. In solution, proteins and peptides undergo more degradation reactions (oxidation, aggregation, hydrolysis) than in the dry state (Wang, 1999). This is why the pharmaceutical industry freeze-dries fragile proteins (Wang, 2000). These reviews cover proteins in general, not TB-500 specifically, but the principle applies to both formats.

• Vial: freeze-dried powder, more stable in the dry state. It has to be put into solution before an experiment, with the handling and sterility questions that this step brings.
• Pen: ready-made solution, no reconstitution. In exchange, the product is more sensitive to degradation and needs an unbroken cold chain (2 to 8 °C) from the warehouse to the refrigerator.

In short, the pen buys convenience, and the vial buys stability and a lower price per mg. For TB-500, the price of that convenience is lower than for most other compounds in the range.

In our checks on October 19, 2026, only one vendor sells a pre-filled TB-500 pen: AuraVia Research, in Europe. We found no other vendor that offers this format.

See the TB-500 Pen on AuraVia Research. This is an affiliate link: Klow Peptide may earn a commission on an order, at no extra cost to you.

Readers outside the EU cannot order this pen. They can compare TB-500 vial vendors, with their delivery areas and certificates of analysis, on our page where to buy TB-500. The same vendor also sells a BPC-157 pen.

TB-500 is a synthetic peptide derived from thymosin beta-4, a 43-amino-acid protein present in almost all nucleated cells. Thymosin beta-4 is the main protein that binds monomeric actin (G-actin) inside cells, which gives it a role in cell migration (Goldstein et al., 2012). TB-500 reproduces the region of the protein that carries much of this activity, built around the LKKTETQ sequence (Sosne et al., 2010).

Most published work concerns the full protein, thymosin beta-4, rather than the synthetic fragment. The best-known studies are preclinical and use animal models: cardiac repair after myocardial infarction in mice (Bock-Marquette et al., 2004), and skin wound repair in diabetic and aged mice with thymosin beta-4 and a synthetic peptide that contains its actin-binding domain (Philp et al., 2003). The most advanced clinical work uses a topical eye formulation of thymosin beta-4 (RGN-259), not TB-500.

Human data on TB-500 itself are limited, and its pharmacokinetics are poorly documented. TB-500 is not an approved medicine, neither in the EU nor in the United States. It is on the World Anti-Doping Agency (WADA) prohibited list, in category S2 (peptides, growth factors and related substances), in and out of competition. For mechanisms, studied areas and safety data, see our TB-500 guide.

You check a pen the same way as a vial, with extra points that come from the solution form.

• Batch and CoA match: the batch number on the certificate of analysis must match the one printed on the pen label or on the box.
• HPLC purity: the CoA should state the purity measured by HPLC and the date of the analysis. AuraVia Research states 99.1% for the TB-500 Pen.
• Cold chain: a product in solution should travel in insulated packaging. Ask the vendor how it ships, and check the parcel when it arrives.
• Complete label: content (10 mg), volume (3 ml), batch number and expiry date must appear on the label or the packaging.
• Sealed cartridge: the pen and its cartridge should arrive sealed, with no sign of opening, damage or leak.
• “Research use only” statement: a serious vendor does not present its pen as a medicine.

An unusually low price should make you cautious. A pen needs a cartridge, a mechanism and cold shipping, so it costs more to produce than a vial.

The TB-500 pen has the same status as the TB-500 vial. In the EU, it is sold for research use only. It has no marketing authorisation as a medicine, neither from the EMA in Europe nor from the FDA in the United States, and the vendor states that it is not for human use. The pen format looks like the pens of approved medicines, such as semaglutide pens, but it does not change this status.

For athletes, TB-500 is on the WADA prohibited list, in and out of competition. Rules on buying, importing and possessing research peptides differ from country to country: check the rules that apply to you before you order. This page is for information only: it gives no medical advice and no usage instructions.