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Judging supplement quality

Many consumers are concerned about the quality of dietary supplements they buy -- from vitamins and minerals to sports nutrition, dieting aids and herbal remedies. The following question is typical of those we receive most often here at SupplementQuality.com:

I looked for [three specific brands of supplements] in your search box and came up empty. What can you tell me about the quality of these three companies and their supplements? They have great prices, but I am concerned that I may be buying low quality supplements as a result.

There are approximately 1000 producers of dietary supplements in the US -- all of whom make more than one product. The task of evaluating them all is monumental in scope, technically challenging, and financially expensive.

Some companies research, manufacture, and sell their own formulations through retail stores, catalogs, and/or the Web. However, most dietary supplements are produced by a few dozen companies -- and are then repackaged or "rebranded" by other companies, ranging from supplement-focused businesses to large "drugstore" chains to local health-food stores.

Manufacturing quality

The quality of any supplement product depends primarily on the quality of the original manufacturer, and secondarily on the distribution-and-storage methods of the reseller and/or wholesale-and-retail distribution system. For details of judging quality, check out these questions you can ask the supplier. Or . . .

A simpler approach to judging quality was supplied by Allison Sarubin, a registered dietitian and author of The Health Professional's Guide to Popular Dietary Supplements, in our interview with her on 8 June 2000.


Some products are being tested by independent labs for purity, potency, and effectiveness of ingredients. Check out our news about testing.


A low price does not necessarily mean low quality. Some producers have chosen to pursue "high volume" strategies -- just as grocery supermarkets make their money by selling a larger volume than the corner convenience stores. They have lower profit margins, but sell many many many more things. Also, repackagers that don't have large advertising budgets find it easier to keep their prices low.

On the other hand, sometimes a low price is due to low quality.

Quality indicators

Here are some strategies for learning about the quality of any dietary supplement.

1. If it carries the ConsumerLab.com quality seal or appears on the list of brands on their www.ConsumerLab.com website that passed their random independent testing program, you can be assured the supplement is high quality and should perform as expected.

2. If it carries the USP or NF seal, the producer is claiming that it meets the US Pharmacopoeia or National Formulary standards for that product. Among other things, these standards cover potency, minimum dosage, and purity from contamination.

3. If it carries the NNFA's "GMP" seal, the manufacturer has passed a comprehensive, independent inspection of its manufacturing process. (This gives solid assurance of a well made product, but says nothing about the manufacturer's choices of which ingredients and potency levels to use.)

4. If it carries the BioFIT trademark, the product has passed "biological assay" testing, which means that it displays biochemical activity that is consistent with having the corresponding effect in the human body.

5. SupplementWatch.com uses a subjective, 100-point system for rating brands. Up to twenty points are awarded for each of five categories: health claims, scientific theory, scientific research, safety and side effects, and value (relative cost).

6. Call the supplement's producer and ask for the head of their quality control or assurance program. (Be prepared to ask a few questions!) This will tell you if they actually have a quality control program. If they don't (they might be a reseller or rebrander), ask how they deal with quality control issues.

Two key questions to ask about quality

1. How do they choose which ingredients and formulas and potency levels to use in a product?

If the company doesn't do their own research (which few supplement companies can afford to do), the ideal answer involves some combination of using monograph information for herbs, doing literature reviews of clinical research, and staying abreast of current research reports.

Procuring quality ingredients involves a combination of testing raw materials and developing relationships with suppliers whose products are of consistent quality.

2. How do they test their products for quality control?

Here, the ideal answer involves sending a sample of each batch to an independent testing lab, using testing methods developed through the Institute for Nutraceutical Advancement. Or, equally ideal, having the independent lab procure random samples "off the shelf".


Sources: Wyn Snow.




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