Building muscle is a numbers game: and protein is the headline figure. To trigger maximum muscle protein synthesis you need at least 24g of complete protein per serving, with roughly 2.5–3g of leucine to flip the anabolic switch. The picks below are filtered for high per-serving protein, complete amino profiles, and proven brands lifters trust. We've ranked them by value score (grams of protein per dollar) so you get the most muscle-building fuel for your budget: across whey blends, isolates, mass gainers and casein.
Meta-analyses by Morton et al. (2018) and the International Society of Sports Nutrition position stand both converge on the same number: lifters in a calorie surplus maximise muscle gain at roughly 1.6 to 2.2 grams of protein per kilogram of bodyweight per day: that's about 0.7 to 1.0g per pound. Going higher offers no additional benefit for hypertrophy.
Split this across 4–5 meals of 30–40g each, ideally including one within 2 hours after training. A 24g+ scoop of whey makes hitting that target far easier than food alone.
Whey is better for almost everyone. Mass gainers are only the right choice if you genuinely struggle to eat enough calories: most of their bulk is cheap maltodextrin. If you can hit a calorie surplus with food, stick to a whey blend or isolate and you'll build leaner muscle.
One to two scoops (24–48g) is plenty for most lifters. Use it to fill the gap between what you eat and your daily target of 1.6–2.2g per kg bodyweight. Whole-food protein from chicken, eggs, fish and dairy should still make up the majority of your intake.
Within 2 hours after training is the practical sweet spot. The classic "30-minute anabolic window" has been debunked: what matters most is total daily protein and consistency, not timing to the minute. A pre-bed casein scoop also helps with overnight recovery.
Creatine monohydrate (3–5g/day) is the single most evidence-backed muscle-building supplement after protein itself. It works through a completely different mechanism (ATP regeneration, not amino acids) so the two stack perfectly. Many top picks above are sold by brands that also produce excellent creatine.