Protein powder is the most widely consumed supplement for good reason: it's a convenient, cost-effective way to increase daily protein intake when food alone doesn't cover requirements. Understanding the different types allows you to choose the one that best suits your goals, dietary preferences, and budget.
Whey protein (derived from milk) is the most studied and widely used protein powder. It's fast-digesting, high in leucine (the key amino acid for triggering muscle protein synthesis), and available as concentrate (80% protein, cheaper), isolate (90%+ protein, less lactose), or hydrolysate (pre-digested for maximum absorption speed). Whey is ideal for post-workout when fast protein delivery is beneficial.
Casein protein (also from milk) digests slowly, delivering amino acids over 5-7 hours. It's ideal before bed or between meals when sustained amino acid release is beneficial. Plant-based proteins (pea, rice, hemp, soy) are appropriate for vegans and those with dairy intolerances. Pea + rice protein combination provides a complete amino acid profile comparable to whey. They're slightly lower in leucine content, so consume a slightly higher dose (30-40g rather than 25g) to trigger the same protein synthesis response. Collagen protein is excellent for joint health, gut repair, and skin but is not a complete protein - use it as a supplement to, not replacement for, complete protein sources.