Summary (Key takeaways)
- Don't start with a factory tour—start with a screen. Shortlist by format capability, MOQs, lead times, and rough pricing first.
- Use a three-gate process: (1) detailed questionnaire, (2) document review, (3) on-site or virtual audit. Each gate filters fast.
- Evaluate both doing (what they say they do) and proving (how they document it). FDA cares about both.
- Your product concept drives the bar: claims, allergens, "free-froms," and date codes change what the co-man must prove.
- Build verification into the relationship (testing, audits, KPIs). Trust—but verify.
Who this approach is for (and how to adapt it)
- National / fast-growing brands: You're choosing a partner for multi-year growth. Run the full, gated process.
- Brand-new launchers: Your first orders are transactional. You can simplify—but still use the gates to avoid obvious risks.
Step 0 — Pre-screen to a top 3
Before any deep vetting, filter on the basics:
- Formats & capabilities (capsules, powders, gummies, liquids; blending, encapsulation, filling; in-house vs. outsourced testing)
- MOQs & lead times (be honest about your run size)
- Rough pricing (same spec basis when you compare)
- Location (local/regional is easier to visit and manage)
If the basics don't fit, don't waste time "vetting."
Gate 1 — The screening questionnaire
Purpose: confirm there's a real quality system—not just marketing.
What I ask about:
- GMP program (21 CFR 111): training, deviations/CAPA, change control
- Environmental Monitoring: zones, swab frequency, organisms, actions
- Allergen control: segregation, labeling checks, dedicated tools/lines
- Food defense & security: access control, CCTV, visitor policies
- Supplier qualification: raw-material vetting, approval/denial criteria
- Testing philosophy: every-lot vs. skip-lot; component vs. finished-product; third-party labs and accreditation
- Stability approach: release overages, date-code rationale, studies
- Packaging controls: component approval, line clearance, tamper-evident
Pass criteria: Specific, consistent answers that show mature systems (not "we do as needed").
Gate 2 — Document request (prove it)
Now we ask for redacted copies. "We have it" isn't enough.
Request list (redacted is fine):
- Finished-product specification (identity, purity, strength, composition + micro/chemical limits)
- Sample COA for a similar product (methods, acceptance criteria, lab accreditation, lot traceability)
- Key SOPs/Policies: deviations/CAPA, recalls, allergen control, environmental monitoring, sanitation, change control, training
- Registrations/Certs: FDA registration, dietary supplement GMP audit reports/cert letters, any retail/customer approvals
- Terms & Conditions: payment, label responsibilities, indemnities, retention samples, storage fees, rework rules
What I look for:
- Procedures that guide action (not "notify manager" and stop).
- Specs that include fit-for-purpose methods and acceptance ranges.
- COAs that tie to the spec and show accredited labs.
- T&Cs that don't shove all risk and cost to you.
Gate 3 — Audit & tour (virtual or on-site)
Two lenses: design and discipline.
Design (reducing risk by layout):
- Material & people flows, zoning, air handling, allergen segregation
- Line clearance and label control (UPC/lot/date, over-label risks)
- Storage conditions, pest prevention, tamper-evident features
Discipline (are they living the SOPs?):
- Batch records filled in real time; corrections per SOP
- Sanitation logs, swab results, corrective actions with root cause
- Release documentation that matches COAs/specs
- Ingredient receiving: ID tests, status tagging, quarantine controls
Deliverable: an observation report with severity, required corrections, and due dates. How they respond tells you a lot.
Match the co-man to your product
Bring a draft label (yes, before production). Your claims and callouts drive the bar:
- "Gluten-free," "vegan," "sugar-free," "non-GMO," sports-tested? The plant must prove it.
- Sensitive populations (e.g., pregnancy, diabetes) require tighter controls.
- Date codes? Then we need a stability plan and overages.
Verification plan (trust, but verify)
Bake this into your PO/Master Service Agreement:
- Release tests and acceptance criteria (potency, micro, heavy metals, any claim-critical "free-from" tests)
- Lab accreditation and method class (e.g., HPLC/ICP-MS)
- Retention samples: quantity, storage, access
- Ongoing verification: periodic third-party testing, annual audit cadence, CAPA follow-up
- Performance KPIs: on-time release, deviation rate, right-first-time lots
If it's not in the PO, it probably won't happen.
Quick red flags vs. green lights
Red flags
- "We only test when a customer asks."
- No finished-product spec (or potency-only spec).
- Vague methods on COAs; non-accredited lab.
- Skip-lot micro on high-risk botanicals.
- SOPs that are one page and manager-dependent.
- Indemnity/T&Cs that push all risk to you.
Green lights
- Mature environmental monitoring with trends & CAPA.
- Clear allergen zoning and documented line clearance.
- Product-specific specs with fit-for-purpose methods.
- Every-lot micro for risk-prone inputs; validated ID testing.
- Transparent documentation access and prompt corrective action.
Summary
A good manufacturer is more than shiny equipment. Vet for systems, documentation, and behaviors—then align quality expectations in writing. Your label and claims set the bar; your gates and verification keep it there.