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Whey protein

Strong evidence

Whey protein concentrate / isolate

Strong evidenceMuscleStrengthRecovery

Dose

20-40 g/serving

Daily total

1.6-2.2 g/kg/day

Timing

Flexible

Need it?

Only if short on protein

Does it work?

  • -Yes. It's the most reliable, best-studied way to hit your daily protein target, and protein intake is what drives muscle and strength gains alongside training. But it's a convenience, not a magic powder: if you already get enough protein from food (roughly 1.6 g/kg/day), an extra scoop does almost nothing.

How much · when

  • -Aim for a daily protein total of about 1.6-2.2 g/kg of body weight. Whey is just a convenient way to close the gap food doesn't fill.
  • -Use 20-40 g per serving (roughly 0.25-0.4 g/kg) to maximally trigger muscle protein synthesis. More per sitting isn't wasted, but it isn't extra useful.
  • -Timing is forgiving: anywhere in a window around your workout is fine, but total daily protein matters far more than the exact minute you drink it.
  • -Spread protein across 3-4 meals through the day rather than loading it all at once.

Safety

  • -Whey is safe at typical intakes for healthy people; high protein diets do not harm normal kidneys.
  • -If you have existing kidney disease, talk to your doctor before raising protein intake.
  • -Whey contains lactose; if you're lactose intolerant, a whey isolate or hydrolysate is usually easier to tolerate. Plant blends work just as well if you prefer to skip dairy.

Key research

Related

Educational information, not medical advice. Talk to a healthcare professional before starting a supplement — especially if you're pregnant, nursing, or managing a health condition.

Reviewed Jun 2026

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