BPC-157 vs TB-500
7 min read
BPC-157 and TB-500 are the two compounds most often weighed against each other in recovery research, and they are the two most requested items in that part of our catalog. They are not two versions of the same thing. One is a fifteen-amino-acid fragment of a human gastric protein. The other is a forty-three-amino-acid synthetic thymosin beta-4, three and a half times heavier. That gap shows up on the certificate, in the vial you receive, and in how much diluent each one takes. This guide sets the two side by side using the figures printed on our own certificates of analysis, and covers what actually changes at the bench when you move between them. For in-vitro laboratory research only.
On this page
The two side by side
Every figure below is the same data our certificate of analysis carries for the lot in your hand, not a general reference value.
What each molecule is
BPC-157 is a synthetic pentadecapeptide, meaning a chain of fifteen amino acids: Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. The sequence corresponds to a partial fragment of a protein found in human gastric juice, which is where the name Body Protection Compound comes from. It is widely referenced in tissue-repair, angiogenesis and gut-model research.
TB-500 is a synthetic form of thymosin beta-4, supplied here as the full forty-three-amino-acid N-acetylated sequence rather than a short fragment of it. Thymosin beta-4 is an actin-binding protein, and TB-500 is studied in cell-migration and regenerative research. The trade name and the protein name are used interchangeably across the literature, which is why our specification sheet lists Thymosin Beta-4 and Timbetasin as synonyms for the same item.
So the two are not related sequences, they do not share a fragment, and nothing about handling one tells you how the other will behave in solution.
ConcentrationThree and a half times the mass, and what it changes
At 4963.44 against 1419.56, a TB-500 molecule weighs roughly three and a half times what a BPC-157 molecule weighs. Milligrams are a measure of mass, not of molecules, so equal milligrams of the two are not equal quantities of anything.
Stack that on top of the vial sizes and the gap widens. If you put the same 2 mL of diluent into a 10mg BPC-157 vial and a 5mg TB-500 vial, you get 5 mg/mL in one and 2.5 mg/mL in the other, which is a two-fold difference in mass concentration and close to a seven-fold difference in molar concentration. Anyone carrying a working volume across from one compound to the other without recalculating is not running the comparison they think they are.
The arithmetic itself is not judgement, so do not do it in your head. Enter the vial strength and your diluent volume in the reconstitution calculator and it returns the concentration and the exact draw for each vial separately.
At the benchHandling: what is the same, and what is not
Most of the handling is identical, and that is worth stating plainly because the differences are easy to over-think:
- Both arrive as lyophilized powder and both are stored the same way before reconstitution, at -20°C, with a 36 month shelf life on the unopened vial.
- Both are reconstituted with the same technique. Diluent runs down the glass wall, the vial is never shaken, and the cake is left to dissolve on its own.
- Once in solution, both follow the same rule: refrigerated at 2 to 8°C, upright, out of light, and used within roughly 28 days when bacteriostatic water was the diluent.
What genuinely differs is the volume decision. A 10mg vial and a 5mg vial reconstituted to the same concentration need different amounts of diluent, and a 5mg vial reaches a given concentration in half the volume. That is the one number to work out per compound rather than per order. The step-by-step method is in how to reconstitute research peptides, and the temperature and shelf-life detail is in how to store research peptides.
Research contextWhy the two appear together
The reason these two names turn up in the same sentence so often is not that they are chemically related. It is that the published preclinical literature places them in overlapping subject areas: BPC-157 in tissue-repair, angiogenesis and gut models, TB-500 in cell-migration and regenerative models. Two different molecules, two different mechanisms described in that literature, one broad research area.
That is also the limit of what can honestly be said here. These are research reagents supplied for in-vitro laboratory work, and nothing on this page is a claim about outcomes, a protocol, or a recommendation to use either compound in any living subject.
VerificationTelling them apart on the certificate
The mass difference that complicates the arithmetic makes verification straightforward. LC-MS reports an observed mass, and 1419.56 against 4963.44 is not a distinction anything can blur. If a certificate reports a mass that does not sit where the named compound should, the label and the contents disagree, and that is the whole point of reading the document before you open the vial.
This matters more for TB-500 than for BPC-157, because the TB-500 name is used in the market for two different things: the full forty-three-amino-acid sequence, and a much shorter fragment of it that weighs a fraction as much. The name on the vial will not tell you which one you have. The observed mass on its certificate will.
Every lot we release is assayed by reverse-phase HPLC and mass spectrometry, and the certificate is matched to the batch number printed on the vial. Look any batch up on the verify a certificate page, and how to read a certificate of analysis explains what each result on it means.
QuestionsBPC-157 and TB-500 questions
Are BPC-157 and TB-500 the same kind of peptide?
No. They have different origins, different sequences and different masses. BPC-157 is a fifteen-amino-acid fragment corresponding to a human gastric protein. TB-500 is a forty-three-amino-acid synthetic thymosin beta-4. They share a research area, not a chemistry.
Why is TB-500 sometimes listed with a much smaller molecular weight?
Because the name is applied to two different products. Some suppliers sell a short fragment of the thymosin beta-4 sequence under the TB-500 name, and it weighs a fraction of the full molecule. Ours is the complete forty-three-amino-acid N-acetylated sequence at 4963.44, and the LC-MS mass on the lot certificate is what settles which one is in any given vial.
Does one need more bacteriostatic water than the other?
It depends on the vial strength and the concentration you are working at, not on the compound itself. Our BPC-157 ships as a 10mg vial and our TB-500 as a 5mg vial, so the same diluent volume lands them at different concentrations. Work each vial out separately in the reconstitution calculator.
Do they store differently once reconstituted?
No. Both follow the same rule: refrigerated at 2 to 8°C, upright, protected from light, and worked within roughly 28 days when bacteriostatic water was used. Lyophilized, both keep at -20°C with a 36 month shelf life on the unopened vial.
Which vial sizes do you supply?
BPC-157 is listed at 10mg, with 5mg and 20mg also available from the dosage selector on its product page. TB-500 is supplied as a 5mg vial. Both are in stock and dispatch the next business day, and both carry a per-batch certificate of analysis.
Both compounds are released lot by lot, each with its batch number on the vial and its HPLC and LC-MS certificate on file. Read the specification and current lot for BPC-157 or TB-500, or look up any batch on the verify page before you order.