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Whey protein
Strong evidenceWhey protein concentrate / isolate
MuscleStrengthRecovery
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
- International Society of Sports Nutrition Position Stand: protein and exerciseJ Int Soc Sports Nutr · 2017 · Position stand
- A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adultsBr J Sports Med · 2018 · Meta-analysis
- Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysisAm J Clin Nutr · 2012 · Meta-analysis
- No Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance ExerciseInt J Sport Nutr Exerc Metab · 2018 · Meta-analysis
Related
Supplements
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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