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Reviews

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Moderated for spam only — the critical ones stay up. Verified purchase badges mean the reviewer’s email matches a real order.

4.6
Average rating
74
Published
78%
Verified buyers
Clear
June 2026

Mass-spec confirmed the fragment

Expected vs found mass on the COA matched our own ESI-MS read. Good to see acetate content reported too — most vendors hide the counterion. Clean documentation.

Sofia AlvarezVerified purchase

TB-500 (Thymosin Beta-4)

July 2026

COA matched to the decimal

Being able to look up the certificate by lot number before ordering is the whole reason we switched. Documentation is impeccable.

Independent ResearcherVerified purchase

TB-500 (Thymosin Beta-4)

July 2026

COA matched to the decimal

Lyophilized cake dissolved fully in bacteriostatic water with no cloudiness or residue. Net peptide content on the COA let me hit exact working concentrations.

Dr. S. NakamuraVerified purchase

TB-500 (Thymosin Beta-4)

July 2026

Good — wish the vial had more headspace

Purity and identity were on point. Only nitpick is the vial is a touch small for larger diluent volumes — minor.

Dr. D. ReidVerified purchase

TB-500 (Thymosin Beta-4)

July 2026

Great product, shipping a day slow

Purity and identity were on point. Only nitpick is the vial is a touch small for larger diluent volumes — minor.

Dr. N. Duarte

TB-500 (Thymosin Beta-4)

July 2026

Reordering for the next cohort

Packaging was discreet and protective, labels crisp, and the lot resolved to a real report in the COA vault. Zero complaints.

Anders L.Verified purchase

TB-500 (Thymosin Beta-4)

June 2026

COA matched to the decimal

Ordered the 5-vial bundle — per-vial pricing is fair and the volume discount applied exactly as shown. Smooth checkout.

Mara M.Verified purchase

TB-500 (Thymosin Beta-4)

June 2026

Exactly what a supplier should be

Dispatched same day, arrived sealed with legible lot numbers. The batch report was already in the vault before the package landed.

Priya L.Verified purchase

TB-500 (Thymosin Beta-4)

June 2026

Good purity, cold pack intact

Arrived with the gel pack still cold and vials undamaged. HPLC purity as stated. Handling instructions on the insert were clear about −20 °C storage.

K. OseiVerified purchase

TB-500 (Thymosin Beta-4)

May 2026

Reliable, small label gripe

No issues with the material itself. The label print was slightly faint on one vial but still fully legible.

Liam K.

TB-500 (Thymosin Beta-4)

May 2026

No cloudiness, no residue

Being able to look up the certificate by lot number before ordering is the whole reason we switched. Documentation is impeccable.

Analytical Chemist

TB-500 (Thymosin Beta-4)

May 2026

Sealed, labeled, traceable

Ran our own analytical HPLC on the lot and it agreed with the published COA within tolerance. Identity confirmed by MS. This is what a research supplier should be.

Verified Buyer

TB-500 (Thymosin Beta-4)

May 2026

Fast, sealed, documented

Dispatched same day, arrived sealed with legible lot numbers. The batch report was already in the vault before the package landed.

Dr. M. Vance

TB-500 (Thymosin Beta-4)

May 2026

Reliable, small label gripe

No issues with the material itself. The label print was slightly faint on one vial but still fully legible.

Dr. N. NakamuraVerified purchase

TB-500 (Thymosin Beta-4)

May 2026

Batch data lines up

Packaging was discreet and protective, labels crisp, and the lot resolved to a real report in the COA vault. Zero complaints.

Rosa A.

TB-500 (Thymosin Beta-4)

May 2026

Purity confirmed in-house

Lyophilized cake dissolved fully in bacteriostatic water with no cloudiness or residue. Net peptide content on the COA let me hit exact working concentrations.

Mara S.Verified purchase

TB-500 (Thymosin Beta-4)

May 2026

Sealed, labeled, traceable

Being able to look up the certificate by lot number before ordering is the whole reason we switched. Documentation is impeccable.

Sean E.Verified purchase

TB-500 (Thymosin Beta-4)

April 2026

Reordering for the next cohort

Ran our own analytical HPLC on the lot and it agreed with the published COA within tolerance. Identity confirmed by MS. This is what a research supplier should be.

Dr. R. Halvorsen

TB-500 (Thymosin Beta-4)

April 2026

Reliable for repeat study designs

We qualify every batch and PepBiotech's COAs make that painless. Lot lookup on the site is exactly what our QA needs for traceability.

Lab Procurement

TB-500 (Thymosin Beta-4)

March 2026

The transparency I was looking for

Lyophilized cake dissolved fully in bacteriostatic water with no cloudiness or residue. Net peptide content on the COA let me hit exact working concentrations.

Anders B.Verified purchase

TB-500 (Thymosin Beta-4)

March 2026

Good — wish the vial had more headspace

No issues with the material itself. The label print was slightly faint on one vial but still fully legible.

Yuki N.Verified purchase

TB-500 (Thymosin Beta-4)

March 2026

Lab-grade and verifiable

Ran our own analytical HPLC on the lot and it agreed with the published COA within tolerance. Identity confirmed by MS. This is what a research supplier should be.

Liam W.Verified purchase

TB-500 (Thymosin Beta-4)

March 2026

The transparency I was looking for

Being able to look up the certificate by lot number before ordering is the whole reason we switched. Documentation is impeccable.

Verified Buyer

TB-500 (Thymosin Beta-4)

March 2026

Great product, shipping a day slow

Everything checked out against the COA. Shipping took a day longer than expected but arrived well packed.

Independent ResearcherVerified purchase

TB-500 (Thymosin Beta-4)

Longer stories

Why people switch to verified

I qualify incoming reference materials for a shared research facility, which means I re-test what vendors send. PepBiotech's COAs consistently match my own HPLC and mass-spec reads. That reproducibility is the entire point of a research supplier, and most don't clear the bar.

Dr. Sarah OkaforAnalytical chemist · academic core facility

For complex analogs like the incretin peptides, the fatty-acid side chain is where cheap material fails. Their mass-spec data accounts for it against the theoretical mass. I can hand a student a vial and a COA and trust the experiment starts from a known quantity.

David Chen, PhDPrincipal investigator · metabolic signaling

Traceability is non-negotiable for us — every material has to map to a lot and a certificate. The lot-number lookup and per-batch COA library make our QA audits painless. It's the transparency standard the research-peptide space badly needed.

Dr. Amelia RostovaLab manager · contract research