What SuppCo’s Amazon Testing Reveals (and Why Buying American-Made Vitamins Matters)

For SuppCo’s original lab report and full dataset, see their 2025 testing retrospective .

If you’ve ever tossed a “best-seller” supplement from Amazon into your cart and just trusted the reviews, the latest independent lab data from SuppCo should be a wake-up call.

Across four rounds of testing on 44 best-selling Amazon supplements, SuppCo found that half of the products failed to deliver what their own labels promised. That’s not a small problem—it’s a sign that where you buy your supplements, and which brands you trust, matters more than ever.

In this article, we’ll walk through what SuppCo uncovered and why choosing American-made supplements from reputable brands like Mt. Angel Vitamins is one of the most important quality decisions you can make.

What SuppCo Tested (and Why It Matters)

SuppCo is an independent consumer health platform that buys supplements the same way you do—off the shelf, with no heads-up to the brand—and sends them to third-party labs for testing. For this Amazon project, they:

• Purchased 44 best-selling supplements on Amazon.com anonymously.
• Focused on four hot, high-demand categories: creatine, NAD⁺, urolithin A, and berberine.
• Measured whether the products actually contained the active ingredient at the level claimed on the label.
• Re-tested failing products to confirm that bad results weren’t just a fluke batch.

What came back from the lab would make any quality-focused manufacturer cringe.

The Big Red Flag: A 50% Failure Rate

When SuppCo compared lab results to label promises, the picture was blunt:

• 22 out of 44 products failed to meet their label claim for the main active ingredient.
• In 20 of those 22 failures, the product contained only about 0–3% of the claimed dose.

In other words, many of these supplements weren’t “a little off.” They were effectively empty—almost none of the ingredient you thought you were paying for was actually there.

That’s not a labeling typo. That’s a breakdown of quality control from raw material sourcing all the way through finished product testing.

Where Are These Failing Products Coming From?

SuppCo dug deeper to understand what kind of companies were behind the worst offenders.

Foreign-Registered Amazon Brands: 100% Failure in This Sample

SuppCo identified a group of supplements on Amazon sold by companies registered outside the U.S. (including mainland China, Hong Kong, and Vietnam). In this subset:

• Every single foreign-registered product in the sample failed the active-ingredient test.

While the sample size is still limited, a 100% failure rate in that group is a serious red flag about oversight and consistency for products being shipped directly into the U.S. market.

The Alibaba → Amazon “Copy-Paste” Pipeline

SuppCo then looked on Alibaba.com (a wholesale marketplace) to see if the same products showed up there as private-label “templates.”

By searching for terms like “creatine gummies,” “NAD+ supplements,” “urolithin A capsules,” and “berberine supplements,” they found that:

• 17 of the 22 failing Amazon products had matching label art or product photos on Alibaba.
• In many cases, it appeared you could simply choose your bottle, upload a logo, and start selling.

That suggests a common pattern: generic formulations made for whoever wants to slap a brand name on the label, with minimal evidence of a real company standing behind the product and its quality.

Gummy Vitamins: Candy First, Active Ingredient… Maybe

If you love gummy supplements, this part may sting:

• 6 out of 8 gummy products tested (75%) failed the active-ingredient test.

Formulating a gummy that both tastes like candy and delivers a full, stable dose of nutrients is technically difficult and expensive. The more focus goes into taste and texture, the easier it becomes to cut corners on the actual active ingredients.

SuppCo even noted that the few gummies which did test accurately tended to taste less like candy—because real, meaningful doses of certain nutrients simply don’t taste like sugar.

The “Too Cheap” and “Too Strong” Warning Signs

SuppCo’s retrospective pulled out two patterns that any shopper can use when evaluating supplements online:

1. Failing Products Were About 38% Cheaper

On average, the products that passed testing on Amazon were significantly more expensive than the ones that failed. When SuppCo averaged the numbers:

• Passing products were around $44 per bottle.
• Failing products were around $27 per bottle.

That’s roughly a 38% price gap. While price alone doesn’t guarantee quality, “suspiciously cheap” is often a sign that something—typically raw material quality or real testing—is being sacrificed.

2. Mega-Dose Labels Were More Likely to Fail

SuppCo also found that, outside of creatine, the failing products were often the ones bragging about huge “mega-dose” amounts on the front of the label.

• For NAD⁺ supplements in the Amazon sample, every product claiming more than 1,000 mg per serving failed lab testing.

The bigger the number on the label, the more it seemed to signal marketing hype instead of real, verified content. That’s the opposite of how supplement labels should work.

When There’s No Real Brand Behind the Label

SuppCo added one more simple test: can you even find the brand online?

• For 13 of the 44 products, they could not locate a real direct-to-consumer website for the brand.
• All 13 of those “no-website” brands failed the lab test.

If there’s no real company you can research—no story, no manufacturing information, no contact details—that’s usually not a brand planning to be around in 10 years. It’s just a logo on a bottle.

SuppCo even found that several failing products were being sold directly by Amazon’s own wholesale channel (“Sold by Amazon.com”), which shows that even large platforms aren’t catching all the bad actors for you.

What SuppCo’s Checklist Means for You

Based on the patterns in the data, SuppCo highlighted several risk factors that often showed up in failing products:

• Stock-looking products also sold on wholesale platforms with generic label templates.
• No real brand website or company presence you can research.
• Prices far below other products in the same category.
• “Miracle” mega-doses that seem out of line with what most reputable brands use.
• Gummies that focus on tasting exactly like candy instead of delivering real doses.

In other words: when you can’t see who is behind the product, and the label promises the moon for a bargain price, your odds of getting what you paid for drop dramatically.

Why Buying American-Made From Reputable Brands Matters

None of this means that everything made overseas is low quality, or that everything made in the U.S. is perfect. But SuppCo’s findings confirm a simple reality:

Products from anonymous, short-lived brands are much more likely to disappoint you—and your health—than products from established, reputable companies committed to long-term trust.

When you choose American-made supplements from brands like Mt. Angel Vitamins, you’re not just supporting domestic manufacturing:

• You’re choosing products that are designed with real science behind them, not just label claims.
• You’re buying from a company that expects to be held accountable by informed customers.
• You’re more likely to get transparent labels, realistic dosages, and meaningful quality control.

Mt. Angel Vitamins: How a Reputable Brand Approaches Trendy Ingredients

Take NAD⁺ support as an example—a category that exploded on Amazon and was part of SuppCo’s testing focus.

Instead of chasing “biggest number on the front of the bottle” claims, Mt. Angel Vitamins has built NAD⁺ support formulas with a systems approach:

• Using well-studied NAD⁺ precursors like NMN and NR to feed the body’s natural NAD⁺ salvage pathway, rather than just slapping “NAD+ 1500 mg” on a label.
• Including methylation support (such as TMG, also known as betaine) because aggressively driving NAD⁺ pathways increases demand on the body’s methylation system.
• Adding complementary nutrients like resveratrol and zinc, along with absorption support, to help tie NAD⁺ increases to real cellular processes such as mitochondrial function and DNA repair.
• Listing clear, specific ingredient amounts on the label instead of hiding everything in vague “proprietary blends.”

This is the opposite of the anonymous, “max-dose, lowest-price” pattern that showed up again and again in the Amazon products that failed testing.

How to Protect Yourself as a Supplement Shopper

You don’t need a lab in your garage to make smarter supplement choices. If you take away nothing else from SuppCo’s Amazon testing and the broader NAD⁺ and methylation science, remember these guidelines:

1. Start with the brand, not the algorithm.
   Don’t just click the top “Best Seller” or “Sponsored” product. Look for a real company with a website, product education, and a track record.
2. Be skeptical of ultra-cheap products.
   Quality ingredients and real testing cost money. If something is significantly cheaper than the rest of the category, that’s a red flag, not a bargain.
3. Be cautious with huge “miracle” doses.
   If one NAD⁺ supplement claims doses far beyond what you see from reputable brands, remember that in SuppCo’s testing, every ultra-high-dose NAD⁺ product failed.
4. Treat gummies as a special case.
   Gummies can be great for taste and convenience, but 75% of the gummies in the SuppCo sample failed testing. If you use gummies, make sure they’re from a brand you genuinely trust.
5. Prefer American-made, science-driven formulations.
   Choose brands that can explain why each ingredient and dose is there, not just shout a big number on the front of the bottle.

The Bottom Line

SuppCo’s Amazon testing didn’t just catch a few “bad apples.” It revealed a deeper problem:

• High failure rates among popular products.
• Generic, private-label formulas being pumped into the market with minimal transparency.
• Gummies and mega-dose labels that often look exciting but don’t deliver.
• A clear pattern: anonymous, ultra-cheap brands are far more likely to fail basic quality checks.

In that environment, choosing American-made supplements from reputable brands like Mt. Angel Vitamins becomes more than a preference—it’s a practical safety and quality strategy.

This article is for educational purposes only and is not medical advice. Always talk with your healthcare provider about which supplements are right for you. But as a shopper, you can absolutely demand more: real ingredients, real testing, and real brands that stand behind every bottle.

To dive deeper into the lab data behind these findings, you can read SuppCo’s full 2025 supplement testing retrospective .