Do you really need protein powder?

Short answer

No. Protein powder adds about 0.3 kg of extra muscle when your daily protein falls short, and that's it. Getting your daily total from foods like meat, eggs and milk (about 113 g a day for a 70 kg person) works just as well.

Do you really need protein powder?
'No protein shake, half the gains' — is that true?
At the gym, a protein shake after training looks like a given. We checked whether skipping powder really stops muscle growth, starting with how big the effect actually is.
Extra protein does help
But the extra muscle is 0.30 kg
An analysis that pooled 49 studies with 1,863 people found that those who added protein while training gained 0.30 kg more lean mass (muscle and everything except fat). The heaviest weight they could lift once went up 2.49 kg more.
But training itself did far more
Of a 27 kg strength gain, protein's share was 2.49 kg
In the same analysis, training raised the heaviest weight people could lift once by 27 kg on average. Extra protein added 2.49 kg on top, about 9%. Training builds the muscle and strength. Protein plays a supporting role.
So when does it help?
When your daily total falls short
In the 49-study analysis, once daily protein passed about 113 g for a 70 kg (154 lb) person, eating more added no extra muscle. Another analysis of 5,402 people found that below 91 g a day for a 70 kg person, every extra 7 g added 0.39 kg of lean mass. Above that, it added 0.12 kg.
It's the protein, not the powder
Milk worked too
20 people were split in two for 12 weeks. Right after training and 1 hour later, one group drank 500 mL of fat-free milk and the other a carb drink with the same calories. The milk group gained more lean mass (1.9 kg vs 1.1 kg). An analysis of 1,552 people found milk (1.18 kg) nearly matched whey powder (1.24 kg).
A recent analysis points the same way
Powder made no difference to lean mass
A 2026 analysis pooling 12 studies with 261 people found no difference in lean mass between those who took whey or soy powder and those who didn't. The whey group gained 8.87 kg more on the bench press and 9.60 kg more on the squat.
Bottom line: powder is a convenience
Just one way to hit your daily total
Protein powder adds muscle only when your daily protein falls short, and even then its share is small next to training. For a 70 kg person, about 113 g a day from meat, eggs, milk and other foods is enough. Powder works when getting there with food is a hassle.