I tend to steer clear of protein supplements (specifically whey) for three basic reasons. The first is that it is cow’s milk protein (20%) and I tend to avoid such things because a) cows are fed all sorts of things other than grass, b) dairy products tend to lead to excessive mucous production, and c) I suspect they are complicit in inflammation.
Second, there is the concept of agni or digestive fire which can, in many people, be like an ember of a fire. When a full throttle of logs is tossed onto an ember it is often extinguished leading to digestive issues. This is especially applicable in the morning after waking.
Third, there seems to be some connection (perhaps more) between reduced or obstructed bile flow through the liver (cholestatic liver injury) as a result of the organ having to work to process excess protein and amino acids.
As if this weren’t enough I prefer to be able to find out something about the supplements like who’s actually making them, what processes they are using in production, and in what concentrations, not to mention their corporate behavior patterns. Many supplements are poorly formulated and are produced by a single company then branded for the brick and mortar operations. You can often see the phrase "produced and bottled for (merchant name). It is not their formula, their product, their manufacturing.
I do believe that we’ve tainted our food, air, and water supply over the last 70 years to the point where quality supplementation is necessary, however I prefer to do that through food-grade herbs whenever possible.
I take too many things to list but it includes neem, supercritical turmeric and several products from the sunrider line. Since we don’t see the sun but seven weeks a year here in Seattle I take several thousand IU’s of Vitamin D. And since I’ve had a round or two of antibiotics in my lifetime I take probiotics.