Purity isn't a promise.
It's a published number.
Every lot is third-party verified and released with a Certificate of Analysis you can pull up in seconds.PureX Bio supplies research-grade peptides for the researcher who reads the data before the marketing. Every lot is third-party verified and released with a Certificate of Analysis you can pull up in seconds.
- ≥ 98.0%
- RP-HPLC purity spec per lot
- COA
- Published for every lot shipped
- 1,000+
- Researchers supplied
- 7 days
- Live support, 7am–7pm ET
Best sellers
Top researched
The PureX standard
Six commitments. Zero exceptions.
Independently verified
Every lot goes to an independent U.S. laboratory for RP-HPLC purity and LC-MS identity confirmation before release.
Documented, not claimed
Lot-level Certificates of Analysis are published in the COA library. Check the numbers before you open the vial.
Screened beyond purity
LAL endotoxin (≤ 0.05 EU/mg), sterility to USP <71>, total yeast & mold to USP <61>/<62>, heavy metals by ICP-OES and pH.
Handled like it matters
Lots held at −20 °C, desiccated and light-protected, shipped in an insulated shipper — frozen gel packs are an optional add-on at checkout.
Released against a specification
A lot is only offered for sale once its analytical results have been reviewed against the applicable specification and its Certificate of Analysis is published.
Same-day fulfillment
Orders placed by 5pm ET ship the same day in a shipper designed to arrive research-ready.
Lot release
Nothing ships until the release results say it can
Supplier documentation, independent U.S. laboratory testing and a specification review — every step recorded against the lot number printed on your vial.
- RP-HPLC purity ≥ 98.0% with the chromatogram published
- LC-MS identity and HPLC potency in mg/vial
- Endotoxin, microbial, heavy metals and pH where the lot panel includes them
- Cold-chain packed and dispatched same day before 5 PM EST
Testing methods
Release testing, published per lot
Identity, potency and purity are confirmed by an independent laboratory before a lot is released, alongside endotoxin, microbial, heavy-metal and pH testing. The exact panel varies by lot — review the lot-specific Certificate of Analysis for the tests and results that apply.
Identity by LC-MS
Liquid chromatography–mass spectrometry confirms the material in the vial is the compound named on the label.
Compound confirmed
Potency by HPLC assay
Quantitative HPLC assay reports how many milligrams of peptide are actually in the vial, printed on the certificate.
mg/vial reported
Purity by RP-HPLC
Reverse-phase separation with area-percent integration of the main peak against all eluted species.
Spec ≥ 98.0%
Endotoxin by LAL
Quantitative LAL screen for bacterial endotoxin in the finished lyophilised material.
Spec ≤ 0.05 EU/mg
Sterility to USP <71>
Finished-product sterility assessment for viable microorganisms, reported as growth or no growth.
No growth
Total yeast & mold
Microbial enumeration to USP <61>/<62> so fungal bioburden is measured, not assumed.
Within limits
Heavy metals by ICP-OES
Arsenic, cadmium, lead and mercury measured against action limits, each analyte reported individually.
Within limits
pH of the reconstituted sample
pH is measured and reported for the lot; many lots also carry water activity and residual solvent results.
Spec 5.0 – 8.0
- Peptide content disclosed
- Independent U.S. third-party testing · Fulfilled and shipped from the USA
- Same-day dispatch before 5 PM EST
- Every lot HPLC tested
Verified buyers
What buyers say about PureX Bio
Reviews are limited to sourcing, documentation and service. We do not publish research outcomes.
4.9 / 5
800+ verified purchases
“The ordering process was straightforward, and the product documentation was detailed. The material arrived well-packaged and met our expectations for laboratory use.”
“PureX Bio delivered our order quickly, and every item was well protected during shipping. Their support team answered our technical questions promptly, which made the entire process hassle-free.”
“We appreciated the consistent documentation and clear product specifications. The overall purchasing experience was smooth and professional.”
FAQ
Answers before you order
Still unsure about a compound, a lot, or a shipment? Our team answers technical questions 7am–7pm ET.
Contact the teamBuying for a lab or clinic-adjacent study?
Wholesale pricing, lot reservations, and bulk COA packages for qualified institutions and distributors.