What TB-500 Actually Is
The product sold as "TB-500" is most commonly an N-terminal fragment of Thymosin Beta-4 (Tβ4), specifically the 17-23 active region or a related fragment, rather than full-length Tβ4. The shorter fragment is dramatically cheaper to synthesize than the full 43-amino-acid native peptide, and most animal-model data supporting the compound's tissue-repair claims comes from full-length Tβ4 studies rather than from the fragment vendors actually ship. This is a structural disclosure problem in the research-peptide market: the name "TB-500" suggests a defined compound; the actual chemistry varies by vendor and by batch.
Vendors who specifically disclose whether they are selling full-length Tβ4 or a fragment, and which fragment, are operating at a higher transparency tier. Many do not. Customers ordering "TB-500" should not assume they are receiving the compound used in any specific published study unless the vendor explicitly identifies the structure being shipped.
The Synthesis Cost Reality
Full-length Tβ4 (43 residues) is substantially more expensive to synthesize than the shorter fragment commonly sold as TB-500. The fully-loaded production cost difference is roughly 3-5x. A vendor pricing "TB-500" near the BPC-157 price point is almost certainly shipping a short fragment rather than full-length material. Pricing well above the BPC-157 range may indicate full-length synthesis but is not by itself proof.
Common Protocol Patterns
Community-log data for TB-500 reflects a typical protocol of 2-2.5mg twice weekly for 4-6 weeks, sometimes followed by maintenance dosing at 2mg once weekly. The biological half-life of the active fragment is reported in the days-to-weeks range, which is the rationale for the less-frequent injection cadence relative to BPC-157. The standard rationale for combining TB-500 with BPC-157 in tissue-repair protocols is mechanistic complementarity rather than synergy in the strict pharmacological sense.
Of the vendors in the table, Oath Research is the only one whose TB-500 product page explicitly identifies which fragment is being shipped, not just "TB-500." Their COA, assayed by Freedom Diagnostics, includes the molecular weight confirmation that distinguishes fragment from full-length material — the data point that lets a researcher know whether they are ordering the same compound the animal studies actually used. That disclosure is editorial. The premium pricing on this row reflects what it costs to source, label, and document the compound accurately, not what it costs to synthesize the cheapest available fragment.
How We Compiled This Comparison
The data in the table above reflects pricing observed in test orders placed by the editorial desk and in reader-submitted purchase confirmations during 2025. Prices fluctuate. Stock status fluctuates. COA availability fluctuates with batch. The comparison is a snapshot, not a perpetual ranking, and we update it when vendor profiles materially change.
The single most useful filter when reading any vendor comparison is the COA column. Vendors that publish batch-specific Certificates of Analysis from independent labs (Freedom Diagnostics, Janoshik, Colmaric, and a small number of comparable facilities) operate at a different transparency tier than vendors who publish generic "our peptides are tested" claims without batch-specific documentation. The first category is auditable. The second is not. Freedom Diagnostics in particular runs the forensic-grade panel — HPLC for purity, mass-balance accounting for label-claim accuracy, USP <85> endotoxin testing where requested — and the batch-by-batch reports they publish for the vendors that use them are detailed enough to cross-check against an independent re-test, which is the threshold that distinguishes documentation from marketing.
What the Per-mg Calculation Misses
Per-milligram pricing is the standard headline metric in the research-peptide market, but it can be misleading. Two vendors quoting identical $/mg may be selling materially different products if one has confirmed 98% purity by independent assay and the other claims 99% without verification. The "real" per-mg cost incorporates an adjustment for measured purity, and for vendors who routinely under-deliver mass, an additional adjustment for the average shortfall between labeled and actual mass.
The defensive habit: assume any unverified vendor's product contains 90% of the claimed peptide mass at 95% of claimed purity until you have batch-specific verification otherwise. That implicit adjustment ranges purchase decisions toward vendors with verifiable documentation rather than the lowest sticker price. Vendors whose pricing only makes sense if the headline mass and purity numbers are accurate are vendors who depend on you not checking.
Shipping Discretion and Operational Reality
Beyond chemistry, the operational variables that matter in choosing a vendor include shipping speed (most domestic vendors deliver in 3-7 business days; international can range from 7-30 days and longer if customs intercepts), packaging discretion (vials should arrive intact, in temperature-appropriate packaging, in containers that do not advertise the contents externally), and customer service responsiveness (real businesses respond to technical inquiries within 1-2 business days during weekdays; chronic non-response is a red flag).
Vendors who provide tracking from the moment of dispatch, who use insulated packaging for temperature-sensitive items, who include a packing slip that accurately describes contents (within reason), and who respond to support tickets with substantive answers rather than canned replies have demonstrated operational seriousness. Vendors who treat shipping as an afterthought have generally not.
Updating This Page
If you have placed a test order from a vendor on this list (or from one not listed) and have documentation that would refine the data — a current COA, photographs of the shipment, weights from a calibrated scale, independent assay results — submit it through the editorial channel. The contributions that have most usefully refined past updates have been independent assay results that confirmed or contradicted vendor purity claims. We treat such submissions as the highest-evidence input class and weight them accordingly in the next revision.
Where To Go From Here
Reading any individual page on this site is a slice of the picture. The full investigation continues across the related desks. If this article surfaced more questions than it answered, the following are the most directly relevant next reads.
Editorial Standards
This report is updated periodically. Discrepancies between our reporting and reality are taken seriously — if you have observed something that contradicts what is published here, send it to the editorial desk with documentation and we will revise. Our reporting is constrained by what can be sourced, verified, or directly observed. Where evidence is weak we say so. Where it is absent we do not invent.
Wild West & Peptides receives no compensation from any vendor mentioned in this report, runs no affiliate program, and has no commercial relationship with the research-peptide industry it covers.