Lab Testing for USA Dietary Supplements

This page outlines laboratory testing considerations for USA manufacturers of Dietary Supplements.

Vivariant can assist producers of dietary supplements with the following types of tests:

Nutritional information analysis required to generate a portion of the supplement facts label
Batch testing the levels of each dietary ingredient in the finished product
Batch testing for product safety including heavy metals and microbial contaminants
Identity testing for input materials where required

The specific lab testing requirements for dietary supplements are outlined in the Code of Federal Regulations (CFR) Title 21, Part 111. This part covers Current Good Manufacturing Practice (CGMP) in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements.

One of the first points of consideration is the nutritional content of the supplement listed on the supplement facts label. This is very similar to food labels and is typically generated with a one-time analysis per formulation which measures Fat and fat composition, Protein, Carbohydrate, Cholesterol, Sugar (laboratory measures total sugar, manufacturer indicates how much is ‘added sugar’), Dietary Fiber, Iron, Calcium, Sodium, Potassium, Energy (calories), Vitamin D. If any of these are not present in significant portions they do not need to be listed on the label but a study must be done to show that the formulation was analyzed to determine this.

Regarding finished product testing, 21 CFR 111.75 (Testing and examination of dietary supplement products) states that manufacturers must perform appropriate tests or examination to verify the finished product. This includes testing for contaminants such as microbes and heavy metals and ensuring that the product contains the ingredients that are listed on the label at a dosage that is within defined specification levels for the product.

Regarding testing/verification of inputs, 21 CFR 111.76 (Testing and examination of dietary ingredients) states that manufacturers must conduct appropriate tests or examination to verify the identity of any dietary ingredient before it is used in a dietary supplement.

When designing their specifications, manufacturers need to decide whether a dietary ingredient listed on the supplement facts label is quantified by testing the final product (“assay”) or “quantification by input”. Identity testing is of particular importance for herbal ingredients such as whole herbs, powdered herbs or herbal extracts. These types of materials are “quantified by input” whereby the identity test/CofA on the input material, combined with the batch record for how much was added, serves as the documentation to confirm the level in the final product.

One of our most frequent questions at we receive from dietary supplement customers, knowing when to quantify an ingredient by input and when to quantify by testing of the finished good. For example:

In the above product, a laboratory test would be conducted on each batch of product to test that the listed amino acids are present at the levels indicated plus or minus a defined acceptance criteria. This is because amino acids are single molecular targets for which laboratories have methods to perform testing, even if they are combined with other ingredients. As described above the caloric content is usually determined only once per formulation during the nutritional analysis.

In this supplement the herbal materials Chamomile flower and Hyssop leaf would be quantified by input, not by testing of the final product. The reason for this is that these are “complex herbal materials” which themselves consist of numerous chemicals and there are no valid laboratory methods that can confirm their levels in a finished good once they have been combined with other materials. In this case, the manufacturer would validate their label claim with a) a test report or vendor CofA confirming the identity of the raw material and b) their batch records showing how much of the herbal material was added. As discussed above the calories and carbohydrate portion of the label is determined from a one-time nutritional study on the product formulation.

21 CFR 111.75(2)(D) also calls for periodic re-confirmation of test results from supplier certificates of analysis.

Note that in all cases, safety testing such as heavy metals analysis and microbial testing occurs on the finished good. This is because even if input materials are tested for these contaminants they can still be introduced during the manufacturing process.

Many of our clients use a third party manufacturer to white label or contract manufacture their supplement. This is an effective business practice to save on capital costs, we strongly advise requesting that your manufacturing partner provide you with: 1) the certificate of analysis for the finished product, 2) the batch records for that lot # of your supplement and 3) the certificate of analysis for each lot # of raw material that was used in it’s manufacture. Having these on hand will assist with navigating regulatory inquiries from the FDA and, if you chose to list there, Amazon dot com will also ask for some of these documents.

It is important to note that these regulations are subject to change, and manufacturers should consult with the FDA to ensure that they are in compliance with the latest requirements.