Why qualify a supplier
Research results are only as reliable as the materials behind them. Qualifying a supplier up front saves you from finding out mid-project that a lot can't be traced, a certificate can't be verified, or the next order won't match the last.
1. Where it's made
- Does the supplier manufacture, or resell material made elsewhere? Ask for the facility address.
- What is the fill environment? Look for a classified cleanroom, such as ISO 5 filling inside an ISO 8 room, with environmental monitoring.
- Are there written procedures and a batch record for each lot?
2. Lot traceability
- Is every vial labeled with a lot number?
- Can you get the CoA for a specific lot quickly, without emailing and waiting?
- Does the CoA name an independent testing lab you can contact?
3. Published specifications
A supplier should state its acceptance limits before you buy: minimum purity, content tolerance, endotoxin limit and the methods used. Results without published specifications can't be compared from lot to lot.
4. What ships with an order
- Packing list matching lot numbers
- Safety Data Sheet (SDS)
- Research-use-only declaration
- Access to each lot's CoA
5. Commercial terms
- Minimum order, pack size and whether volume pricing applies per item or across the order
- Accepted payment methods
- Order cutoff and typical ship time
- Policy for damaged or incorrect shipments, and the reporting window
- Whether the supplier vets buyers. A supplier that checks who it sells to takes compliance seriously.
Checklist
| Question | What good looks like | PepDistro |
|---|---|---|
| Manufacturing | Named facility, classified cleanroom | Phoenix, AZ · ISO 5 fill in ISO 8 room |
| Traceability | Lot on every vial, CoA per lot | QR code on every vial → lot CoA |
| Testing | Independent lab, published specs | Third-party lab named on each CoA |
| Minimums | Clear, per item | None; packs of 10 vials |
| Volume pricing | Transparent tiers | Pack tiers, per item, applied in account |
| Shipping | Stated cutoff | 3 pm Arizona time, usually same day |
Ready to compare? See wholesale terms or apply for an account.