It depends on the brand, but most combine two or more of WPI, WPC and casein, sometimes with added collagen, creatine or vitamins mixed in. The exact formula varies from product to product.

Neither is strictly better, it comes down to what you're after. A blend gives you a mix of fast and slower digesting protein in one scoop, while straight WPI or WPC each lean into one specific benefit, whether that's purity or value.

Generally yes. Blends are often cheaper than pure WPI while still offering a higher protein percentage and faster digestion than a WPC-only formula, so you're not paying isolate prices for every scoop.

Whey blends are designed to be versatile, so they work well post-workout, between meals, or even before bed depending on how the blend is formulated. Check the label if you want to match it to a specific time of day.

Yes, many blends are formulated specifically with lean muscle in mind, combining fast-digesting protein for recovery with a lower carb and fat profile.

Most do, since they're built from dairy-based proteins like whey and casein. If you're avoiding lactose, a plant-based protein would be a better fit.