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cGMP Guidelines for Dietary Supplements

cGMP Guidelines for Dietary Supplements

pile of dietary supplements

Current Good Manufacturing Practices (cGMP) are a set of guidelines maintained by the United States Food and Drug Administration (FDA) to help promote consumer safety. There are different cGMP guidelines for pharmaceutical drugs, foods, as well as dietary supplements.

The FDA’s cGMP guidelines area nasty business to wrap one’s head around— legally-worded, immense in size, and covering a great number of concerns. These guidelines describe how to produce safer more efficacious products but aren’t enforced or verified by the FDA before products ship.


  • cGMP Guidelines help ensure product safety
  • The FDA doesn’t actively enforce cGMP compliance
  • Third-party agencies such as NSF & NPA offer GMP-Certification
  • Buying third-party GMP-certified products helps to better assure safety


Dietary supplements exist in a somewhat grey-area of regulation in the United States. They don’t require the same safety and quality assurance standards of foods and pharmaceuticals. In the FDA’s own wordsThat means that these firms are responsible for evaluating the safety and labeling of their products before marketing.

The FDA maintains a series of cGMP guidelines for dietary supplements but doesn’t play an active role in enforcing them prior to product distribution. They will take action upon reports of violations but do not require inspections prior to selling products.

That means a supplement company could be selling products with unlabeled ingredients, toxins such as mold and heavy metals, and even omit the active ingredients long before the FDA would take any action.

This system is better than nothing but leaves a lot of room for disaster. Many of the highest-quality supplement brands use third-party cGMP-Registration services to help demonstrate their commitment to quality.

The Problem

The biggest shortfall of the FDA’s cGMP for dietary supplements is its retroactive role in protecting consumers. On the one hand, having more lax regulations allows consumers a greater degree of access to products. On the other hand, it leaves them at risk to companies that ignore safety standards for any number of reasons (usually money, for one reason or another.)

FDA cGMP Violations

The FDA maintains a list of products and/or manufacturers that have received warning letters for violations of cGMP. These warning letters may be related to trace amounts of toxins, adulterated products, products containing unapproved ingredients, and several other concerns.

The FDA maintains a holistic database of cGMP warning letters, but it’s a bit nasty to sort through. The Council for Responsible Nutrition (CRN) has a much more streamlined database that is specific to warning letters issued to supplement manufacturers. This is an ideal place to search to see if your favorite supplement brand has received cGMP violations in the past.

It’s important to realize that just because a company appears in this database doesn’t mean they should be avoided forever. Violations come in many shapes and sizes and can range from innocent misunderstandings of advertised health claim phrasing to full-fledged inclusion of unlabeled ingredients.

The Solution

Fortunately, there are third-party groups such as the NSF that provide manufacturers a certification process. These services allow manufacturers to have their products, facilities, and ingredients certified as being in accord with the FDA’s cGMP guidelines. This

NSF GMP-Registered

The National Sanitation Foundation (NSF) is an international organization that—essentially—helps ensure consumer products don’t post a health risk. The NSF is not an enforcement agency and only offers certification services to manufacturers.

NSF GMP-Certification helps consumers recognize brands and products that have undergone an added stage of safety precautions. In addition to GMP-Certified, NSF offers a Certified For Sport service that guarantees products to be free of substances banned in many competitive sports.

NSF Certified For Sport is an advisable requirement for any supplement purchased by a professional athlete.

NPA GMP Certification

The Natural Products Association (NPA) has been around since the 1930s and serves as a trade association for—you guessed it—natural products. Within their purview are supplements, foods, probiotics, and even non-consumable health products.

The NPA offers several certification services for products that include those certifying products to contain only “natural” ingredients, their Informed Choice certification to certify products free of banned substances, and also a GMP certification program. Any or all of these can be used by manufacturers to help consumers know their products are safe and have been tested prior to sale.

The Guidelines

Below you’ll find a basic outline of what the cGMP guidelines detail. This summary has been condensed from descriptions available from the NSF and NPA both. This summary is only meant to offer consumers a general idea of what cGMP means. If you’re considering starting a supplement company please consult the NSF, NPA, or FDA websites for a fuller description.

Raw Materials Testing

When a manufacturer orders new raw ingredients they must test them upon receipt to ensure they are as expected. This includes testing for impurities, contaminants, and identity testing. The FDA does allow a company to petition for exclusion of 100% identity testing based on where the ingredients come from. Basically, if the source is cGMP compliant assuming the ingredients are pure can speed things up.

In-Process Testing

Currently, finalized FDA-stated cGMP guidelines do not specify an in-process protocol. Proposed rulings (likely to be adopted in some capacity) do mention the requirements of manufacturers to establish in-process control points wherever necessary to limit contaminants, assert identity, and verify potency.

Finished Product Testing

Every batch of supplements meet product specification for purity, strength, and identity as well as being free of contaminants or unlabeled ingredients. Manufacturers are required to develop and maintain documentation of this process which describes the steps taken to assure its effectiveness.

Testing Requirements

The FDA does not maintain a list of specific testing that must be done for every ingredient approved for use in dietary supplements. Their official stance is to allow manufacturers to choose the analysis methods most appropriate on an ingredient-by-ingredient basis.

Expiration Dating

The FDA’s cGMP guidelines do not require manufacturers to list product expiration dates. However, if a date is listed, manufacturers are required to provide scientific support for that date. This includes “best buy,” “use by,” and “best before” type phrasing on products. While not required, including a best-buy date helps signify a product has had an extra degree of stability testing prior to sale.


In addition to testing for the identity of ingredients, pre-production, post-production, and in-process testing, and label auditing, cGMP sets forth guidelines to help manufacturers deal with other aspects of their business in a way to better serve consumers. These include the following:

  • Procedures for inspections by the general public or authorities
  • Procedures for product recall
  • Guidelines for maintaining required documentation
  • Guidelines for employee training and/or certification on cGMP requirements
  • Guidelines for labeling and qualified health claims


I think it’s important to assess the GMP status of any supplement product one buys. The major shortfall of the FDA cGMP guidelines is that it creates an assumption that the FDA is actively enforcing it before products reach the shelf. I remember feeling like I’d misread something when I first learned that.

Looking for products with trusted third-party GMP certifications such as NSF and NPA is a great step to assure your products don’t contain junk. I consider NSF Certified for Sport and NPA Informed Choice certifications as “no-brainers” for competitive athletes that choose to take supplements. For everyone else, my opinion is basically why wouldn’t you choose GMP-Certified if available?