You've changed how you eat. But not how you supplement.
Most people are more careful about food than ever. Reading labels, choosing whole ingredients, avoiding ultra-processed products. But collagen powders and protein supplements rarely get the same scrutiny. Most are engineered from isolated ingredients, sweetened with stevia or sucralose, and bulked out with fillers.
If you wouldn't accept that from your food, it's worth asking why you'd accept it from your supplements.