Consumers generally take for granted that the contents inside a bottle of supplement X matches exactly the label on the outside. Fortunately and for the most part, thanks to the rules currently in place, this is true. However, there are multiple opportunities during production where the contents of the bottle may no longer be represented correctly by the label. Somewhat analogous to bicycle frame builders, most brands of nutritional supplements are manufactured in a limited number of facilities, or contract labs. It's not economically feasible for a small company with a product line of nutritional supplements to have its own production facility.

Contract labs specialize in production of supplements, analytical testing, and packaging. These labs can be either cGMP or non-cGMP compliant at this time, and the resulting product could be affected by the way the company treats each batch of product being produced. Until 2010, supplements can be legally produced in non-cGMP facilities. The actual contract lab used by any given supplement company is usually a guarded secret as part of one's competitive advantage. Therefore, rather than looking to the name on the bottle, one must look at the actual contract lab as the source of the product, and the inherent production risks.

From start to finish at a contract lab

a) Starting Materials

Most contract labs source their raw materials from a wide range of outside suppliers, many of whom specialize in certain classes of materials, such as amino acids, protein powders, minerals, etc. Each supplier provides to the contract lab a certificate of analysis (COA) that is issued for each and every lot (batch) of raw material. Suppliers can be located overseas or domestically with the actual starting material produced anywhere around the world.

When raw materials are received by a contract lab, they should be positively identified. This is usually done easily and quickly by near infrared (NIR) spectroscopy. By matching a characteristic fingerprint spectrum of the raw material with a reference spectrum for the material, identity can be confirmed. Purity (the percent active content of the material) is not usually assayed at this time, depending on the COA of the material for this and any other details. This is the first intersection where impurities that originated in the starting material factory or packaging would enter the contract lab undetected. Note that the NIR identity confirmation is not sensitive to pick up foreign matter in the raw material and is a bulk test only.