How To Check Supplement Quality: A Guide To Avoiding Fakes and Scams

Shopping for vitamins online offers undeniable convenience, but it also presents a hidden danger: the rise of counterfeit, expired and improperly stored products. With the US Food and Drug Administration regulating food supplements differently from prescription medications, the burden often falls on consumers to verify the quality.

Whether you are buying magnesium, probiotics or protein powder, knowing how to spot a high-quality product versus a fake one is essential for your health. This guide breaks down exactly how to vet brands, interpret labels and avoid the pitfalls of third-party marketplaces.

Key takeaways: The quality checklist

• Check the seller: Avoid 'commingled' inventory on general marketplaces; prioritise retailers with climate-controlled warehouses.
• Review certifications: Look for products with third-party testing seals like USP, NSF or Informed Choice.
• Read the 'other ingredients': Watch for unnecessary fillers, artificial dyes or allergens.
• Verify the claims: If a product claims to 'cure' a disease or works 'immediately', it is likely a scam or non-compliant with FDA regulations.
• Inspect the bottle: Check for a lot number, expiry date and intact safety seals immediately upon arrival.

1. Understand the risks: The 'marketplace' problem

Inventory commingling

Recent investigations have highlighted a significant issue with buying supplements from general online marketplaces rather than dedicated health retailers. A major risk is inventory commingling.

On massive eCommerce platforms, third-party sellers can send their products to a central fulfilment centre. These products are sometimes thrown into the same bin as the 'official' brand’s inventory. Even if you click on 'buy' from a reputable brand page, you might receive a counterfeit bottle sent in by a fraudulent third-party seller.

The temperature trap

Heat destroys potency. Probiotics, omega-3s and proteins are sensitive to temperature. General marketplaces often store supplements in warehouses alongside lawnmowers and books, without climate control. If a probiotic sits in a 100°F warehouse in July, the bacteria are likely dead before they reach your doorstep.

The fix: Buy from retailers that utilise climate-controlled distribution centres and do not allow third-party sellers to touch the inventory.

2. Carefully read supplement labels

The US Food and Drug Administration (FDA) regulates food supplements as food, not drugs. This means the FDA does not approve supplements for safety or effectiveness before they hit the market. However, they do strictly regulate labelling.

What to look for:

• Supplement information panel: This is a mandatory requirement. It must list the serving size, amount per serving and the 'Percent Daily Value' (%DV).
• Proprietary blends: Be cautious here. Brands can list a 'blend' of ingredients without disclosing the exact dosage of each. This is often a way to hide that a formula is mostly cheap filler with a dusting of the expensive active ingredient.
• The 'FDA Approved' myth: If a supplement label says 'FDA Approved', put it back. The FDA does not approve supplements. Legitimate brands will use the disclaimer: 'These statements have not been evaluated by the Food and Drug Administration.'

3. Look for the gold standard: Third-party testing

Since the FDA does not test every batch of vitamins, you need to look for brands that pay independent labs to do it for them.

Look for these trusted seals on the bottle:

• USP Verified (United States Pharmacopeia): Confirms the product contains the ingredients listed and dissolves properly in the body.
• NSF International: Checks for contaminants like heavy metals and pesticides. Crucial for professional athletes (NSF Certified for Sport).
• ConsumerLab: An independent watchdog that tests products for potency and purity.
• iTested (exclusive to iHerb): A programme where products are tested by an independent third-party lab, with the Certificate of Analysis (COA) posted publicly for transparency.

4. Spot scams or 'miracle' claims

The New York Department of State’s Division of Consumer Protection recently issued warnings regarding deceptive marketing in the health and wellness space.

Red flags of a supplement scam

• 'Cures' disease: Supplements cannot claim to treat, cure or prevent diseases.
• Fake reviews: If a product has thousands of reviews, but they are all posted within the same week or use identical phrasing, they are likely to be bot-generated.

5. Do a physical inspection: What to do when it arrives

Quality control doesn't end at the checkout button. Once the package arrives, perform this 3-point inspection:

1. Check the safety seal: Under the cap, the inner seal should be tight and intact. If it is lifted, punctured or missing, do not consume it.
2. Find the lot number and expiration: Legitimate manufacturers print a Lot # (for tracking recalls) and an Expiration or Manufacturing Date (MFG) on the bottom or side of the bottle. If this is missing, the product is suspect.
3. The 'smell check': While B-vitamins and Valerian Root naturally smell strong, fish oil should not smell like rotting fish (a sign of rancidity/oxidation), and probiotics should not look discoloured due to moisture exposure.

Summary table: Where should you buy?

Final thoughts

Your health is an investment. While searching for the lowest price is natural, a 'cheap' supplement that contains no active ingredients – or worse, contaminants – is a waste of money and a health risk. Stick to transparent brands, verify third-party testing and purchase from retailers that prioritise supply chain integrity over speed.

References:

1. New York Department of State Division of Consumer Protection."Consumer Alert: Scams and Deceptive Marketing."dos.ny.gov
2. U.S. Food and Drug Administration. "Food Supplements: What You Need to Know." fda.gov