5 supplement-buying mistakes that could cost you

Buying supplements online couldn’t be easier. Search for what you want, compare prices and reviews, click a button and a bottle can be on your doorstep within days.

But supplements aren’t quite like ordering socks or printer paper.

You’re buying something you intend to put inside your body — sometimes every day for months or years. And when you purchase through an online marketplace, you may not always know as much as you think you do about where that bottle came from.

Counterfeit supplements are a real problem. ConsumerLab has documented reports involving well-known products and brands sold through Amazon and other online marketplaces and recommends purchasing directly from a brand’s website when possible.

That’s not a reason to stop shopping online. It’s a reason to shop more carefully.

Here are five common supplement-buying mistakes to avoid — plus five reasons going directly to the brand may be the safer, better choice.

5 reasons to be careful buying supplements online

1. Counterfeits can look surprisingly convincing

In 2023, NOW Foods discovered 11 counterfeit versions of its supplements being sold on Amazon by one seller.

At first glance, the products looked like NOW supplements. But there were differences in the bottles and labels, and some were missing UPC or lot numbers. When NOW tested the capsules, the company reported finding primarily white rice flour — and trace amounts of sildenafil, the active ingredient in Viagra, in some samples.

Other counterfeit supplement cases have involved products from Pure Encapsulations, PreserVision and additional brands.

The lesson? Recognizing the label isn’t necessarily enough.

2. You need to know who’s actually selling it

One of the easiest details to miss on a marketplace is the name next to “Sold by.”

The page may feature the brand you recognize while the actual seller is another company entirely.

That company could be a legitimate authorized reseller. But when you’re buying something you’re going to swallow, it’s worth checking.

ConsumerLab recommends buying directly from the brand when possible or checking whether a third-party retailer is an authorized seller. GoodRx similarly recommends going directly to the brand’s website and, when using Amazon, verifying who is actually selling the product.

3. A great price isn’t always a great deal

Everyone loves saving money.

But if a supplement normally costs $40 and an unfamiliar seller suddenly offers it for $17, that’s a reason to do a little homework before celebrating your bargain.

An unusually low price doesn’t prove a product is fake.

But if the manufacturer and established retailers are charging considerably more, it’s worth asking how an unfamiliar seller can offer such a steep discount.

4. Reviews can’t tell you what’s in your bottle

Reviews can tell you whether people liked a product, thought the capsules were easy to swallow or had problems with delivery.

They can’t authenticate the bottle that’s going to arrive at your house.

That’s an important distinction.

So don’t let thousands of positive reviews substitute for checking who is actually selling the supplement and whether the manufacturer recognizes that seller.

5. The supply chain may be harder to trace

There has been particular concern over the years about Amazon’s practice of “commingling,” in which identical products belonging to different sellers could be used to fulfill an order.

Amazon has announced an end to commingling. As of March 31, 2026, its rules require resellers to use Amazon barcodes so their inventory can be tracked separately. Amazon’s own guidance also notes that older stickerless inventory already in its fulfillment network before the change does not have to be relabeled.

The changes are encouraging. But they don’t change one of the simplest ways to take uncertainty out of the equation: Go directly to the source.

5 reasons to buy supplements directly from the brand

If you take a particular supplement regularly, consider purchasing from the manufacturer’s own website.

Here are five reasons why.

1. You have greater confidence it’s authentic

This may be the biggest advantage of all.

When you purchase directly from the brand, there’s no third-party seller standing between you and the company whose name is on the bottle.

GoodRx calls purchasing from the brand’s website directly the safest way to buy supplements online, while ConsumerLab similarly recommends buying directly from a brand as the best way to avoid counterfeit products when possible.

Authorized retailers can certainly be legitimate sources, too. Many brands list them on a “Where to Buy” page.

2. Guarantees and return policies may be better

Buying direct also means you’re dealing with the brand’s own guarantee, refund or replacement policy.

Some supplement manufacturers offer satisfaction guarantees that provide more flexibility than marketplace return policies.

That’s worth checking before you buy. Amazon, for example, marks many vitamins and supplements as non-returnable because of the potential safety risks involved with returning ingestible products, although damaged or defective products may qualify for a refund or replacement.

A company’s guarantee can be especially valuable if you’re trying a supplement for the first time.

3. You can learn more about what you’re buying

A reputable manufacturer’s website can give you far more information than a marketplace listing.

You may find details about ingredients, sourcing, testing, allergens, manufacturing standards, certifications and quality control.

That’s also where you can investigate claims like “third-party tested.”

Don’t stop at the phrase. Look for information about who performed the testing and what was tested.

4. You can go straight to the company with questions

Suppose you’ve taken the same supplement for two years and suddenly the capsules look different.

Or the label has changed. The seal seems unusual. You can’t find a lot number.

Buying direct gives you an immediate line back to the people responsible for the product.

Even if you purchased elsewhere, contact the manufacturer using information from its official website if something seems wrong. In the NOW counterfeit case, consumers reporting suspicious products helped alert the company to the problem.

5. Buying direct may come with its own perks

Don’t automatically assume Amazon or another marketplace has the best deal.

Supplement brands may offer subscription discounts, loyalty rewards, bundles, promotional offers or free shipping. Some also reserve certain guarantees or benefits for customers who purchase directly or through authorized retailers.

It’s worth comparing.

You may discover that going directly to the source gives you both greater peace of mind and a competitive price.

Before you add the product to your cart

None of this means every supplement purchased through Amazon or another online marketplace is suspect.

Legitimate supplement companies and authorized retailers sell genuine products online every day.

But supplements deserve a little more scrutiny than an ordinary online purchase.

Check the seller. Compare the price with the manufacturer’s own site. Find out whether the seller is authorized. And when your bottle arrives, look at the seal, label, lot number and product itself.

Better yet, when it’s practical, consider buying directly from the company behind the bottle.

Convenience matters. Saving money matters.

But when you’re buying something that’s going into your body, knowing exactly where it came from matters even more.

FAQ: Buying Supplements Online