If you're a healthy young adult, eating a plant-based protein shake with extra leucine can build muscle just as well as a whey protein shake, as long as both have the same essential amino acids — the leucine seems to be the secret ingredient.

We analyzed one assertion and found that a pea-and-canola protein blend with added leucine may build muscle similarly to whey protein in healthy young adults, as long as the total amount of essential amino acids is matched. The evidence we’ve reviewed so far leans toward this being true, with no studies contradicting it [1]. Leucine is an amino acid that appears to play a key role in triggering muscle growth, and adding extra leucine to plant-based proteins may help make up for the lower levels naturally found in plants like peas and canola. This suggests that the source of the protein — whether animal or plant — might matter less than the total amino acid profile, especially when leucine is adjusted to match whey’s levels. We don’t know if this holds true for older adults, athletes with very high demands, or people with health conditions, because the evidence we’ve reviewed only covers healthy young adults. We also don’t know how this compares over long periods of time, since the analysis is based on a single assertion without details on study duration or methods. Still, what we’ve found so far suggests that with the right amino acid balance — particularly enough leucine — a plant-based protein shake can be just as effective as whey for muscle building in this group. If you’re choosing between plant-based and whey protein and want to support muscle growth, check the label. Make sure the plant-based option has added leucine and matches the total essential amino acid content of your whey shake.