TL;DR
Short answer: The factory is the product, so vet documents before you compare prices. This guide lists twelve red flags, each one paired with the green-light behaviour you should demand instead. NDA-gated documentation is normal commercial practice; documentation you cannot obtain at all is the strongest warning sign in this category.
01. No verifiable facility registration
The supplier says "registered" but cannot produce confirmation under NDA. Green light: registration confirmed on request, before any money moves.
02. GMP certificate without scope
A certificate that does not state the audit scope or the dosage forms covered. Green light: the certificate names your dosage form (gummies, softgels, liquids...) and its dates.
03. "FDA approved" claims
Supplement facilities are not "FDA approved" — they register and comply. Green light: precise language — registration, cGMP, audit scope.
04. Anonymous lab on the COA
COAs with no identifiable ISO 17025 laboratory or methods. Green light: lab identity, methods and spec ranges on every certificate.
05. Sample COA instead of batch COA
Refusing lot-specific COAs and offering "the same COA for every batch." Green light: a COA with your batch number, dates and results ships with each lot.
06. No subcontractor disclosure
Key steps (filling, bottling, testing) quietly outsourced with no GMP status shared. Green light: the supplier names subcontracted steps and their compliance.
07. Refusal of NDA documentation
Willing to take money but not to sign an NDA for registration details. Green light: NDA-gated disclosure is offered proactively.
08. Advertised low MOQ, hidden costs
Low entry tier advertised, then film, tooling or label minimums appear. Green light: itemized quote covering formula, packaging, testing and freight.
09. Label errors as a pattern
Panels with unit mistakes, wrong %DV or missing allergens in samples. Green light: FDA-format proofing offered before printing (free in our workflow).
10. No stability or dating logic
Expiry dating that is decorative, or no storage/heat guidance for your route. Green light: clear dating policy and routing guidance per format.
11. One-way communication
Quotes by autoresponder, no named contact, no direct channel when questions get hard. Green light: a named human answers technical questions in the same day.
12. Price that is too clean
A quote so low it implies quality arbitrage somewhere unseen — usually documentation. Green light: transparent line items; the cheapest transparent quote wins.
How do I verify a GMP certificate is real?
Look at who issued it, whether the auditor is an accredited third party, whether the certificate names a scope covering your dosage form, and the audit dates. A scan with no issuer, no scope or no dates proves nothing — see the FDA vs cGMP guide for the full check.
What should I ask for before signing a manufacturing agreement?
The file set: third-party GMP certificate with scope, FDA facility registration confirmation (under NDA), a redacted COA from a recent lot in your dosage form, subcontractor disclosure, and a written statement of what ships with each lot.
Is it normal that a factory will not publish registration numbers?
Yes — for contract manufacturers, registration and certificate details are usually disclosed under mutual NDA to protect supply-chain agreements. Refusal to share them under NDA is the red flag; NDA-gated disclosure is the green light.
Are low-MOQ offers a red flag?
Not by themselves — low entry tiers exist for stock formulas (ours start at 200 bottles). The red flag is a low advertised MOQ with hidden costs appearing later: film or tooling fees, label minimums, or per-line surcharges. Ask what the quoted price includes.
How do I check batch quality after ordering?
When the batch arrives: match lot codes on bottles to the COA, verify the panel matches the formula, check fills and seals, and keep a sealed bottle for records. Every batch should ship with its own COA — if yours does not, that is red flag #13.
Should I compare suppliers on price alone?
Never on price alone. Compare the landed file set: documentation, audit scope, COA standard, communication and freight terms. The cheapest quote that cannot produce paperwork is more expensive than a transparent quote every time.
Request the free sample kit and the full file set — GMP scope, registration under NDA, and a redacted lot COA. Judge us by the same twelve flags.