How to find a reliable supplement manufacturer

Finding the right contract manufacturer is one of the hardest steps in launching a supplement brand. Many founders face slow responses, pushy sales reps, or glossy promises that hide weak compliance systems. Websites all say the same things—“GMP-certified,” “FDA registered,” “quality is our priority”—yet those claims often fall apart under scrutiny.

In this article, we’ll break down how to use FDA inspection data and warning letters to spot red flags. You’ll see why “trust but verify” is the only safe strategy, what common violations look like, and how to avoid being blindsided by poor practices.

Key takeaways

• Don’t trust marketing jargon. Every manufacturer claims to be FDA registered and GMP compliant. That doesn’t prove day-to-day quality.

• FDA inspections are a data point—not a guarantee. They only show conditions at one point in time.

• Warning letters reveal recurring compliance failures. Specs, testing, complaint handling, and labeling issues come up again and again.

• Startups are most at risk. Big brands negotiate stronger processes, leaving smaller clients vulnerable.

• Work with experts. Independent audits and programs like Blue Ocean’s set process help brands avoid costly mistakes.

The problem with “FDA inspected” claims

Many manufacturers advertise that they’ve been inspected by FDA. On the surface, this sounds like a badge of honor—but it’s not. FDA doesn’t “approve” supplement manufacturers. Registration is just filling out a form. And inspections are snapshots in time.

Some facilities pass one year, then fail the next. Others prepare paperwork only when inspectors visit, then slip back into old habits. A manufacturer might tell prospects, “We’ve been FDA inspected every year and passed.” But a deeper look can reveal warning letters and repeat violations.

That’s why “FDA inspected” should be treated as a data point, not proof of reliability.

Case study: Far East Summit LLC

To illustrate, let’s look at an FDA warning letter issued to Far East Summit LLC in 2024.

This company had multiple inspections dating back to 2016. For years, they could legitimately tell clients, “We’ve been FDA inspected.” Yet in 2024, FDA issued a warning letter citing serious violations.

Violations included:

• Unapproved drug claims — products marketed for treating depression, coughs, joint pain, and swelling.

• Failure to establish specifications — no clear identity, purity, or strength requirements for raw materials and finished products.

• No proper complaint investigations — one return involved hallucinations and mood changes, but no investigation was conducted.

• Inadequate raw material testing — pesticides, heavy metals, and microbes were not properly checked.

• Weak foreign object controls — no adequate systems to prevent metal fragments during processing.

• Missing master manufacturing records — no documentation of blend times, processing temperatures, or lot codes.

• Labeling issues — disease claims, inaccurate supplement facts, unsupported expiration dates.

For years, brands working with this manufacturer may have assumed everything was fine—until FDA caught up. By then, those brands were already exposed to recalls, retailer delistings, or enforcement action.

Lessons for supplement brands

1. Specifications matter

Every product needs written specifications for identity, purity, strength, and composition. Without them, testing is incomplete and compliance collapses. Always request product specifications from your manufacturer—and don’t settle for vague assurances.

2. Complaint handling must be real

If a consumer reports an adverse effect, your manufacturer should investigate. Discarding returns without testing is a major violation. As a brand, you need your own system for tracking complaints and ensuring they’re followed up.

3. Labeling reviews are not enough

Some manufacturers say they’ll handle “regulatory checks” for your labels. In reality, it’s usually a quick review. The fine print in contracts always shifts liability back to you. Brands should always commission their own independent label review.

4. Shelf-life must be substantiated

“Best by” dates can’t just be placeholders. FDA expects data to prove them. If your manufacturer can’t provide stability data, your brand is at risk.

5. Big brands get better treatment

Large clients like Costco or Life Extension can demand extra testing and tighter processes. Startups usually don’t get the same unless they negotiate—or have a partner who negotiates for them.

Q&A: Common founder concerns

Q: If a manufacturer is GMP certified, isn’t that enough?
A: No. Certifications are often checklists, and audits can be gamed. You need to verify specifications, complaint handling, and ongoing compliance.

Q: What’s the biggest red flag in a manufacturer pitch?
A: Extremely fast lead times for custom formulas. Proper ingredient qualification and testing take weeks. If someone promises finished product in under four weeks, they’re likely skipping steps.

Q: How should small brands vet manufacturers if they can’t afford a full audit?
A: Start with document requests—product specs, testing protocols, complaint procedures, and master manufacturing records. An experienced consultant can review them quickly and flag issues.

Q: Why not just trust private label catalogs?
A: Many include unsubstantiated or even illegal claims. Use the formulas if they’re sound, but create your own claims and marketing content based on independent substantiation.

Final thoughts

Finding the right contract manufacturer is not just about price or lead times—it’s about protecting your brand from recalls, lawsuits, and retailer bans. FDA inspections and warning letters show us that problems repeat year after year. The lesson: trust but verify.

For startups, the safest path is to work with experienced partners who can translate regulatory language into clear action steps and connect you with manufacturers who truly follow the rules.

Next Steps

Book a 1:1 Consultation (Startups & Emerging Brands)
Two focused hours to review your concept, claims, formula, labeling, and testing plan—plus concrete next steps. Perfect if you’re evaluating manufacturers and want a second set of expert eyes before you commit.

Enroll in SSET — Supplement Startup Essentials Training (Pair it with a consult for best value)
On-demand training that teaches you how to vet manufacturers, set testing & stability programs, build substantiation files, and avoid costly missteps. Includes our vetted contract manufacturer list so you’re not starting from scratch.

Contact Us (Established Brands / Due Diligence & Retail Readiness)
Need an end-to-end compliance tune-up before investor diligence or retail expansion? We’ll audit your systems, fix gaps, and package your dossier so your manufacturing partners—and your business—are investor-ready.

About Blue Ocean Regulatory

Blue Ocean Regulatory helps supplement and functional food brands launch and scale compliance. Core specialties include FDA/FTC label & claims review, substantiation dossiers, cGMP programs, manufacturer vetting, test & shelf-life strategies, and retailer/investor readiness. Our goal: build brands that last—and pass.