Ever since I started Relentless Improvement way back in January of 2005, I've avoided "proprietary formulations" because they exist almost exclusively to cheat the consumer. By disguising doses of individual ingredients it is impossible to form an informed objective buying decision. When you look at a Relentless Improvement product label, you'll find over-disclosure in most cases. Cis or trans-form, percent of standardization, amount of active content broken out. For those that choose to be an informed consumer it's the only way to go.
Here is what ConsumerLab had to say in response to one of their subscriber's questions:
take a supplement containing a "proprietary formula" which lists many
ingredients. Can ConsumerLab test the contents so I'll know the amounts
of each ingredient?
ConsumerLab.com has long cautioned against purchasing supplements with proprietary formulas
and typically does not test them. We may, however, check listed amounts
of other key, individually listed ingredients in the same supplement.
In some cases, we have found high levels of contaminants which, we
suspect, originated from ingredients in a proprietary formula.
The major problem with "proprietary formulas," as well as with
proprietary "blends" and "complexes," is that they permit manufacturers
to withhold important information about what's really in a product. The
company only has to list the total amount of formula, not the amount of each ingredient
in the formula. The formula's ingredients only have to be listed in
weight order, i.e., based on their relative contribution to the weight
of the formula. Furthermore, the formula may change over time without
you necessarily knowing.
Proprietary formulas are often developed around an expensive ingredient, like CoQ10,
because this allows a company to use less of the expensive ingredient,
creating a formula in which the expensive ingredient is just a small
part of the formula. We have seen this with ingredients such as chondroitin in joint supplements, and SAMe. We also see proprietary formulas marketed for uses such as cognitive enhancement, nerve pain, or weight loss
where a company may try to impress the consumer with a laundry list of
ingredients having only shreds of evidence relating to the intended use.
In most cases, the formulas themselves have not been clinically tested."