In Plain English
Your body makes a protein called thymosin beta-4 that helps tissue rebuild after injury. TB-500 is a short piece of that protein, made synthetically, on the theory that the fragment carries the useful part of the signal. Most of the encouraging research is on the full protein, not the fragment being sold — that gap is the single most important thing to understand about this compound.
What people use it for. Recovery and soft-tissue repair, usually alongside BPC-157 rather than on its own — the pairing is what most people mean by a recovery stack.
What to know before you buy. This is the compound where the certificate of analysis matters most. Because there is no agreed definition of what TB-500 is, two vials with the same label can contain genuinely different molecules. Ask for the sequence and the molecular weight, not just the purity percentage. There is also an unresolved theoretical question about whether a compound that promotes tissue growth could also support the growth of tissue you would rather not grow. Nobody has studied that in TB-500 either way.
What It's Used For
| Goal | What that rests on |
|---|---|
| Soft-tissue recovery | Repair and cell-migration signalling reported for thymosin beta-4, the larger parent protein |
| Flexibility and tissue quality | Reported in animal models of the parent protein |
| Stacking with BPC-157 | The most widely used recovery pairing; the two act through different mechanisms |
The left column lists goals people commonly pursue with this compound; the right column states what that rests on. These are described uses and research findings, not proven outcomes or treatment claims. Individual results vary and no outcome is promised.
Pricing & Sizes
Ships sealed and lyophilized — stable for years at room temperature, reconstitute before use, or ask and it will be reconstituted free at the volume shown below. Free shipping on every order, no minimum. Third-party COA available for every batch — HPLC purity and mass spec verification.
At a Glance
- Class
- Synthetic peptide fragment, typically described as a 17-amino-acid sequence from thymosin beta-4 (Tβ4)
- Key distinction
- Tβ4 is a 43-amino-acid protein with its own research literature. TB-500 is a fragment and is not interchangeable with it
- Preclinical
- Repair and angiogenesis signals reported in animal models, largely attributed to Tβ4 rather than the fragment
- Human data
- No completed randomised controlled trial of TB-500
- Reviewed for
- Wound healing
- Regulatory (US)
- Not FDA-approved. PCAC recommended for 503A listing 23 July 2026; no FDA action taken
- Format
- Sold within blends; also as a standalone vial
Regulatory status — read this first
On 23 July 2026 the FDA Pharmacy Compounding Advisory Committee voted 8-6-1 to recommend TB-500 (free base and acetate) for the Section 503A bulk drug substances list. That vote is advisory only. As of 4 August 2026 the FDA has taken no action on it, has not opened rulemaking, and has not moved the substance to the interim Category 1 list. FDA’s own scientific reviewers had recommended against all seven peptides; the committee voted against staff on six consecutive votes, so the usual assumption that a PCAC recommendation predicts the agency’s decision is weaker here than normal. Several outlets have reported this as the FDA “clearing”, “approving” or “adding” these peptides to the bulks list. That is inaccurate. Nothing has been added and nothing is legally cleared.
The Characterisation Problem
This is the issue FDA returned to repeatedly, and it is a practical buying concern rather than an abstract one. “TB-500” is a common name, not a defined substance. FDA noted that exact sequences and molecular weights vary between vendors, and asked the panel directly: when a prescriber writes for TB-500, does anyone actually know what the patient is receiving?
FDA’s Russ Wesdyk compared it to buying a car for a teenager on the manufacturer’s name alone and ending up with “a Volvo with NASCAR specs” — same nameplate, different specification underneath. The agency also stated it lacks authority to define what TB-500 is.
What this means for sourcing
Because there is no settled sequence, a certificate of analysis is doing more work here than with most compounds. Verify the stated amino acid sequence and molecular weight on the COA rather than relying on the product name. Two vials both labelled TB-500 can legitimately contain different molecules.
What the Research Shows
The cancer question
Several panellists raised a possible cancer signal, on the mechanistic reasoning that a compound promoting angiogenesis and cell migration could in principle also support tumour progression. FDA acknowledged during the hearing that there are no studies on TB-500 itself addressing this. The concern is therefore theoretical and unresolved rather than demonstrated — but “unstudied” is not the same as “shown to be safe”, and FDA asked the panel to treat the absence of information as its own data point.
Why it is recommended anyway
The 8-6-1 vote is best read as a judgement about access rather than evidence. Members in the majority described bringing a decision patients are already making into a regulated framework of licensed pharmacies and testing. Dissenters cited the paucity of efficacy data, the tumour-progression overlap, and the proposed use as an injectable.
The bottom line
TB-500 has the weakest direct evidence base of the compounds recommended in July 2026. The supportive research largely belongs to a different, larger molecule. If you are evaluating this compound, the honest framing is a plausible mechanism inherited from Tβ4, no direct human trials, an unresolved theoretical cancer question, and real vendor-to-vendor variability in what is actually in the vial.
Also in the Range
Sold within Wolverine, GLOW and KLOW. All three already contain it, so these are alternatives to one another rather than additions.