"Proprietary Blend" is a standard, legal labeling category — but it's worth understanding what it does and doesn't tell you, since you'll see it on far more than just this product.
What A Proprietary Blend Legally Requires
US labeling rules require the total weight of the blend and every ingredient inside it listed in descending order by amount. They do not require individual milligram amounts for each ingredient — that's the legal gap that makes proprietary blends possible.
What You Can Infer
The listing order is a real clue: ingredients are required to be listed from most to least abundant. On Vasoryn's label, L-Citrulline is listed first, meaning it's present in the largest amount within the blend — though you still can't know the specific number.
What You Can't Infer
You cannot back-calculate individual amounts from the total weight and the ingredient list alone. A blend could be 90% one ingredient and 2% each of the rest, or split more evenly — the label alone doesn't tell you which.
A Practical Approach
When you see a proprietary blend, check the total weight against research doses for the ingredients you care about most (as we've done on our ingredients page). If the total blend weight is smaller than the studied dose of even one key ingredient, that's useful information — even without an exact breakdown.
