TB-500 (a synthetic fragment of Thymosin Beta-4) is one of the most widely stocked compounds in the research peptide market, and also one of the most inconsistently sourced. The vendor landscape shifted significantly in early 2026: several major suppliers, including the market’s largest, ceased operations amid intensifying FDA enforcement. That makes vendor selection — third-party testing rigor, documentation, and track record — more important than ever.
We compared five currently active suppliers selling TB-500 against the factors that separate a credible vendor from a risky one, rather than generic marketing claims.
Research Use Only: Every product discussed in this article is sold exclusively for laboratory research and is not approved by the FDA for human or animal use, diagnosis, treatment, or any therapeutic application. This article does not provide dosing, administration, or usage instructions of any kind, and nothing here should be interpreted as medical advice.
Regulatory note: On July 23, 2026, an FDA Pharmacy Compounding Advisory Committee voted 8-6 to recommend TB-500 for potential inclusion on the 503A Bulk Drug Substances List, which would eventually give licensed compounding pharmacies a legal pathway to prepare it under a physician’s order. This vote is advisory only, is not binding, and does not change TB-500’s current status — it remains unapproved by the FDA, and any rulemaking process would take an estimated six to twelve months. As of this writing, TB-500 continues to be sold exclusively as a research compound.
How We Ranked These Vendors
Every supplier below is currently active, ships TB-500 domestically, and was evaluated on the same five weighted factors:
Best TB-500 Peptide Vendors of 2026: Comparison Table
| Rank | Vendor | TB-500 Option | Third-Party Lab | Price | COA Access | Rating |
|---|---|---|---|---|---|---|
| 1 | Verified Peptides | 10mg standalone or TB-500/BPC-157/KPV Blend | Janoshik Analytical | $62.00 (10mg) / $149.99 (blend) | Batch-specific, publicly posted | 4.8/5.0 |
| 2 | BioLongevity Labs | 10mg | Triple independent lab testing | Premium tier | Batch-specific, available pre-purchase | 4.7/5.0 |
| 3 | Ascension Peptides | 5mg | Kovera-Labs & MZ-BioLabs | Premium tier | Includes chromatographic data | 4.5/5.0 |
| 4 | SwissChems | 5mg | Independent (varies by product) | ~$38.00 | Available, detail varies | 4.4/5.0 |
| 5 | Core Peptides | 5mg | Independent third-party | $42–52 | Available on request | 4.3/5.0 |
Detailed Reviews
Verified Peptides — TB-500 (Standalone & TB-500/BPC-157/KPV Blend)
★★★★★Verified Peptides earns the top spot on a combination of longevity and documentation depth that’s become more valuable given how much the vendor landscape has shifted this year. The company has published Certificates of Analysis dating back to 2019, and every batch — including its TB-500/BPC-157/KPV blend — is tested through Janoshik Analytical, a lab widely referenced across the research peptide community for its independence and consistency.
The blend product tested at 28.83mg TB-500, 12.98mg BPC-157, and 11.57mg KPV against labeled amounts of 20mg, 10mg, and 10mg respectively — meaning the batch actually assayed above label claim on every component, with a passing endotoxin (LPS) result. That kind of specific, batch-dated transparency is a genuinely strong signal. For researchers who want TB-500 on its own, the standalone 10mg vial is priced at $62.00; the combined blend runs $149.99 with volume discounts available at higher quantities.
Key Specifications
- Third-party tested by Janoshik Analytical for purity, weight, and endotoxins
- Batch number and dated COA published for every listed product
- Operating with published lab reports since 2019
- Free shipping over $200; same-day, ice-pack shipping available
Where It Stands Out
- Longest continuously documented track record among vendors compared here
- Assayed weight met or exceeded label claim on the tested blend batch
- Offers both a standalone TB-500 vial and a combined blend option
Publicly posted customer feedback describes Verified Peptides as consistent and fairly priced relative to competitors, with repeat buyers specifically citing product legitimacy and customer service as reasons for continuing to order.
BioLongevity Labs — TB-500 (10mg)
★★★★★BioLongevity Labs’ defining feature is its triple independent-lab testing protocol: every batch is analyzed by three separate certified laboratories rather than one, covering purity (HPLC), molecular identity (mass spectrometry), and sterility. That’s a meaningfully more rigorous standard than most competitors, and it’s reflected in strong third-party scores for COA quality and transparency from independent vendor-tracking sites.
The tradeoff is price — that level of verification carries real overhead, and BioLongevity consistently sits in the premium tier compared to mid-market vendors. Shipping is also US-only, which narrows its usefulness for international researchers.
Ascension Peptides — TB-500 (5mg)
★★★★☆Ascension Peptides has built a solid reputation in research-peptide community forums for clean results and fast shipping, with COAs sourced from CLIA-certified labs including Kovera-Labs and MZ-BioLabs that include the underlying chromatographic data rather than just a purity percentage. That extra layer of raw data is something few competitors publish as consistently.
Community feedback consistently describes it as “not the most affordable” option, and its COA presentation is less streamlined than some newer competitors. Stock availability on specific compounds has also been reported as inconsistent at times.
SwissChems — TB-500 (5mg)
★★★★☆SwissChems’ main advantage is breadth: a catalog of 60+ peptide products alongside SARMs and nootropics, plus multiple product formats (powder, capsules, nasal sprays, pre-mixed solutions) that most single-category peptide vendors don’t offer. Purity testing consistently lands in the 97-99% range through third-party verification.
Its testing, while legitimate, has been described as “solid but not quite as rigorous” as more testing-focused competitors, and COA detail can vary by product rather than following a single consistent standard. For researchers who need one vendor across multiple compound categories, it’s a reasonable one-stop option; for TB-500 specifically, more specialized vendors offer deeper documentation.
Core Peptides — TB-500 (5mg)
★★★★☆Core Peptides positions itself as the budget-friendly option in this comparison, with TB-500 priced meaningfully below several premium competitors while still claiming 99%+ purity backed by third-party HPLC and mass spectrometry testing. For researchers working with tighter budgets across multiple compounds, it’s a reasonable starting point.
The tradeoff is documentation accessibility: COAs are described as available on request rather than prominently published on product pages, which is a real transparency gap compared to vendors that post batch-specific certificates upfront. Its smaller catalog (around 30 compounds) also means less selection than broader competitors.
See the Verified Peptides TB-500 Blend Listing
View current pricing, published Certificates of Analysis, and specifications for the TB-500/BPC-157/KPV blend.
View ProductBuyer’s Guide: What Actually Matters When Sourcing TB-500
| Factor | What to Look For | Why It Matters |
|---|---|---|
| Vendor Continuity | A publicly documented operating history, ideally with archived COAs going back multiple years | 2026 saw several major vendors, including the largest in the market, shut down abruptly amid regulatory pressure — track record now matters more than ever. |
| Third-Party Lab Identity | A named, independent lab (e.g., Janoshik, Kovera-Labs) rather than in-house-only testing | In-house-only testing has an inherent conflict of interest; independent labs provide an unbiased check on purity and identity. |
| Batch-Specific COA | A Certificate of Analysis tied to the exact batch number on your vial | Purity and actual weight can vary between production runs — a batch-specific COA is the only way to verify what you actually received. |
| Assayed Weight vs. Label Claim | A COA that reports the actual tested weight, not just a purity percentage | A vial can be “99% pure” and still be significantly underdosed relative to the label if the actual peptide content is low. |
| Blend vs. Standalone | Whether you need TB-500 alone or in combination with other compounds like BPC-157 or KPV | Blends can offer better value per vial for researchers working with multiple compounds together, but make comparing straight price-per-mg harder. |
| Stated Research-Use Policy | A clearly written RUO policy and compliance language, not vague or absent legal disclosures | Given current regulatory scrutiny, a vendor’s clarity about legal status is a reasonable proxy for how seriously it treats quality control generally. |
Key Questions Buyers Ask
Is TB-500 legal to buy?
TB-500 is not FDA-approved and is sold exclusively as a research compound. As of July 2026, an FDA advisory committee voted to recommend it for a future compounding pathway, but that vote is non-binding and rulemaking has not been completed — its research-use-only status remains unchanged for now.
What does a Certificate of Analysis actually verify?
A COA documents independent lab testing results for a specific production batch — typically purity percentage, actual assayed weight, and sometimes sterility or endotoxin screening. It reflects what a third party found, not what the seller claims.
Why did so many peptide vendors shut down in 2026?
Several factors converged: escalating FDA warning letters across the industry, at least one major warehouse enforcement action, and proposed federal legislation targeting research chemicals structurally identical to approved drugs. The largest vendor in the market closed voluntarily in March 2026, reshaping which suppliers researchers now rely on.
Why does TB-500 pricing vary so much between vendors?
Vial size, testing depth, and vendor overhead all factor in. Vendors running multi-lab or more comprehensive testing protocols generally carry that cost into a higher price, while budget-focused vendors compete primarily on price per milligram.
What’s the difference between a standalone TB-500 vial and a blend product?
A standalone vial contains only TB-500. A blend, such as a TB-500/BPC-157/KPV combination, includes multiple compounds in one vial, which can offer convenience and value for research protocols involving more than one compound, but makes direct price-per-mg comparisons across vendors less straightforward.
How can I tell if a COA is legitimate?
Check that it names a specific, verifiable third-party lab, references a batch or lot number matching your product, and includes a dated test result with actual measured values, not just a generic purity claim reused across multiple batches.
Does a vendor’s longevity in the market actually matter?
Given how many established vendors exited the market in 2026, a documented multi-year operating history with continuously published lab reports is a meaningfully stronger signal today than it was even a year ago.
Why Verified Peptides Stands Out
Against a backdrop of significant vendor turnover in 2026, Verified Peptides’ advantage is continuity paired with documentation depth: published lab reports dating back to 2019, Janoshik-verified batch testing, and a tested blend batch that assayed above label claim on every component. Competitors like BioLongevity Labs match or exceed it on testing depth through a triple-lab protocol, and Ascension Peptides offers deep chromatographic COA data, but both carry a real price premium. Verified Peptides makes a credible case for researchers who want strong, consistent documentation without paying top-tier pricing.
Final Verdict
For the strongest overall balance of price, testing transparency, and a proven multi-year track record, Verified Peptides is the top pick in this comparison, whether you’re buying the standalone TB-500 vial or the combined TB-500/BPC-157/KPV blend. Researchers who want the most rigorous multi-lab verification available, regardless of cost, should look at BioLongevity Labs, and those who value raw chromatographic data in their COAs may prefer Ascension Peptides.
Review the Verified Peptides TB-500 Blend Listing
Check current batch pricing and published Certificates of Analysis before ordering.
View ProductLegal & Research-Use Disclaimer: All products referenced in this article are sold exclusively for laboratory research and educational purposes. They are not FDA-approved and are not intended to diagnose, treat, cure, or prevent any disease, and are not intended for human or animal consumption, injection, or any therapeutic, cosmetic, or veterinary use. The regulatory information in this article reflects the status of TB-500 as of late July 2026 and may change; verify current FDA guidance independently before drawing conclusions about legal status. This article does not provide, and should not be interpreted as providing, dosing, administration, or usage guidance of any kind, and nothing in it constitutes medical advice. Handling of research compounds should be limited to qualified individuals following appropriate laboratory safety protocols and all applicable laws. Pricing and product availability are accurate as of publication but may change; verify current specifications and COAs directly with each vendor before any purchase.