The directories every founder lands on first — Alibaba, ThomasNet, the back pages of Google — are not where the strong factories live. The strong factories don't need to advertise. They take work through trade shows, referrals, and registered-facility databases. The good news is that all three are public.

1. Trade-show exhibitor directories. SupplySide West and SupplySide East publish full exhibitor lists every year — that's the supplement and functional-food world's hiring pool. In-Cosmetics publishes the equivalent for skincare and color cosmetics. Pet category lives at SuperZoo. The exhibitor list is how you build a 200-name candidate pool in an afternoon.

2. The FDA registered facility database. Every U.S. facility producing dietary supplements is required to register with the FDA under 21 U.S.C. 350d. The FDA Food Facility Registration system is searchable and gives you a real list of who's actually licensed to produce. Cosmetics manufacturers register under MoCRA — the Modernization of Cosmetics Regulation Act of 2022 — and that registry is now live too.

3. NSF and NPA member directories. NSF publishes a searchable list of facilities they have certified to GMP, NSF Certified for Sport, or NSF/ANSI 173. The Natural Products Association publishes their GMP-certified facility list. Both are tighter pools than the FDA registration list because both involve real third-party audit.

4. Google Maps by category and metro. Search "supplement contract manufacturer Salt Lake City" or "cosmetics contract manufacturer Los Angeles." The results are mostly real factories with a physical presence. Cross-reference against the registered-facility databases.

5. Competitor COAs. Every Amazon supplement listing has a COA somewhere — sometimes on the brand's website, sometimes shared on request. The COA names the testing lab; the testing lab knows the factories that ship to it; if you can get to the factory name, you have a candidate that's already producing in your category.

None of these five sources is enough by itself. Together they give you 200-500 candidates and the data to filter to a workable shortlist.

Marketing is what factories tell you. Audit history is what regulators told them.

The FDA inspects registered facilities on a risk-based schedule. The inspection outcome — Form 483 observations, warning letters, import alerts — is published. If a facility you're considering has a recent warning letter for "failure to verify identity of dietary ingredient" or "failure to establish product specifications," you're looking at the kind of compliance gap that, six months from now, becomes your problem. The FDA Warning Letters database is searchable by company name and date.

NSF and NPA audit reports are not public, but the certifications themselves are. If a factory tells you they're "NSF certified" and the NSF directory does not list them, the conversation is over. We've seen this happen on first calls — factory claims a certification, candidate types the factory name into the certifying body's directory, no listing, call ends. Saved a lot of money.

For cosmetics, the audit framework is ISO 22716 — the international standard for cosmetic GMP. ISO certification is third-party. Ask for the certificate number, then verify it against the issuing body. ISO certificates are valid for three years; an expired one is the same as none.

For pet products, the FDA's Center for Veterinary Medicine sets the regulatory floor and AAFCO publishes ingredient and labeling standards. Audit posture across pet manufacturers is more variable than supplements; ask harder.

Send this in writing. The factories that respond fully are the ones worth scheduling a call with. The factories that respond partially are telling you something.

1. Audit history. "Please share your most recent FDA inspection date and outcome, your current third-party certifications (NSF, NPA, ISO 22716), and any active enforcement actions." A clean factory will answer in two paragraphs.
2. MOQ and lead time. "First-run MOQ, reorder MOQ, and current lead time for [your specific format] in [your specific category]." Specific number, not a range. Factories that quote ranges are signaling they don't have spare capacity to commit to a date.
3. Certifications and the formulation library. "Which of your current stock formulas in [category] are NSF / organic / vegan / gluten-free certified, and which require additional certification work to claim?" Tells you whether their library actually covers what you need to launch.
4. References. "Three brands currently in production, ideally with shelf presence I can verify." Strong factories give names. Weak ones give "we keep client lists confidential" — sometimes legitimate, often a hedge.
5. Quality control posture. "What in-process and finished-goods testing do you run on every batch, and which testing labs do you use?" The answer should reference identity testing, microbial testing, heavy metals testing, and a named third-party lab. The FDA's Dietary Supplement cGMP overview describes the floor.

This brief takes a factory 30-45 minutes to answer well. If the response comes back in 5 minutes with marketing copy, that's the answer.

The first 30 minutes of a first call tells you almost everything. Watch for these.

Red flag 1: pressure on signing before sampling. Strong factories know that buyers need samples and references before committing capital. Factories pushing you to sign a master service agreement before you've held a sample are optimizing for capacity utilization, not for your launch.

Red flag 2: vague answers on the formulation library. "We can do anything you want" is the wrong answer. The right answer is "we have 47 stock formulas in your category, here's the catalog, here's what we've certified, here's what we'd need to add." Specificity is competence.

Red flag 3: opacity on certifications. "GMP-aware" is not a certification. Some factories use the term to mean their facility runs to GMP standards but isn't third-party certified. That can be legitimate — but you should know the distinction. If a factory uses "GMP-aware" and "GMP-certified" interchangeably, ask which one applies to which line.

Red flag 4: no in-house QA team named. Quality assurance reports up to a named QA director, with credentials. If the factory can't name the person responsible for QA on your batches, the answer is no.

Red flag 5: refusal to share a reference COA. Every factory has dozens of COAs from prior runs. Asking to see one or two with brand names redacted is a normal request. Refusal means the COAs don't exist or don't pass scrutiny.

Red flag 6: pricing that doesn't add up. If a factory quotes you a per-unit number that is 30 percent below the next-cheapest quote on the same spec, something is wrong. Either they're cutting on ingredients, cutting on testing, or planning to come back with a "revised" quote after you've committed.

Domestic typically means the U.S. for U.S.-bound brands. Overseas typically means a sourcing relationship with an EU lab, a Korean cosmetics facility, or a Chinese manufacturer for non-supplement categories.

Domestic wins on regulatory simplicity. An FDA-registered, GMP-audited U.S. facility puts your supplement run inside one regulatory frame. Cosmetics under MoCRA, food under FDA, dietary supplements under 21 CFR Part 111 — domestic factories live in those frames every day. Overseas adds a customs brokerage layer and an import-alert risk that domestic doesn't have.

Domestic wins on lead time. Six to twelve weeks domestic versus 14-22 weeks overseas once you account for production, ocean freight, and customs. The differential matters when a launch window is tied to a retail meeting.

Overseas wins on certain category strengths. Korean labs lead on color cosmetics and complex skincare emulsions. EU labs (Italy, France, Spain) lead on prestige skincare and sun care under the strict EU cosmetics regulation framework. Indian labs lead on certain ayurvedic and herbal formats. If your formula is in one of those buckets, overseas is sometimes the only credible option.

Overseas wins on cost at scale. Below 5,000 units, the freight and customs overhead usually erase the per-unit savings. Above 50,000 units, overseas becomes meaningfully cheaper for many categories. The crossover point depends on category, weight, and value-density.

If you're below 5,000 units on the first run, default to domestic. Use overseas only when category strength, certification, or formula complexity forces it.

Newer founders assume the quote is the quote. Most of it isn't.

Reorder MOQ. Almost always negotiable after a successful first run. The factory has now amortized setup, has a label spec, and has demonstrated the SKU sells. A 1,500-unit first run can usually become a 750-unit reorder.

Sample fees. Many factories charge $100-500 per sample run. A common ask is to credit the sample fee against the first PO. Reasonable factories agree.

Payment terms. The default is 50 percent deposit, 50 percent on shipment. After the first or second successful run, this can shift to 30/70 or net-30 on reorders. Worth asking for explicitly.

Stability testing scope. If you're doing a custom formulation, the factory will quote a stability program — often $3,000-12,000 across 6-month, 12-month, 24-month checkpoints. The 24-month checkpoint is sometimes optional for a launch and can be deferred to year two of the brand. Ask whether you can defer it.

Exclusivity windows. On private-label runs with a real formula modification, a 6-month or 12-month exclusivity window is sometimes available for a 5-15 percent uplift on per-unit cost. Worth asking. Often refused, sometimes granted.

Certification additions. If you need NSF Certified for Sport on a stock formula that doesn't have it, the factory can sometimes add the certification — at your cost. The cost is usually a one-time $8,000-25,000 plus an annual maintenance fee. Worth knowing the price before you decide whether you need the certification at all.

The quote tells you what the factory is willing to commit. Three things you verify before you sign.

1. Facility verification. Pull the factory's address from the quote and run it against the FDA Food Facility Registration database, the NSF directory, and the NPA member list. Confirm the facility number on the quote matches what's registered. We've seen quotes come back with one address on the letterhead and another on the COA — that's a brokerage situation where the actual production happens elsewhere. Sometimes legitimate, always worth knowing.

2. Insurance certificate. Product liability insurance with a per-occurrence limit of at least $2 million is standard for supplement and cosmetics manufacturing. The factory should be willing to issue you a certificate of insurance naming your brand as additional insured. If they refuse, you're carrying the liability.

3. Reference call. Schedule a 20-minute call with one of the references the factory provided. Ask about lead-time predictability ("did they ship on the date they committed to?"), QA responsiveness ("when something went wrong, how did they handle it?"), and reorder pricing ("did the per-unit cost stay where it was quoted?"). One reference call is usually enough — the answers cluster.

Skip these three steps and you're trusting marketing. Run them and you've eliminated the bottom third of factories before signing anything.

If you've never sourced before, the realistic timeline from "I want to find a manufacturer" to "I'm holding a sample" is 6-10 weeks if you do the work yourself, 3-5 weeks if you delegate the discovery.

Doing it yourself: 1 week to build the candidate list, 2 weeks to send the vetting brief and receive responses, 1-2 weeks to schedule and run discovery calls, 1 week to receive sample-fee invoices and pay them, 2-4 weeks for samples to arrive. The bottleneck is usually scheduling — strong factories book discovery calls 2-3 weeks out.

Delegating: a sourcing partner who already knows the factories shortcuts the discovery and the vetting. We typically come back inside 36 hours with three matched factories, MOQ + lead time + indicative cost on each, and have samples in hand 2-3 weeks after the brief is signed.

Either way, start with the brief. Format, fill, target retail price, certification asks, target launch date. Without it the vetting questions don't have a frame.