Hormonal

Supplementing plant-based proteins (specifically soy or pea) with extra leucine or essential amino acids can equalize the muscle protein synthesis response to whey protein, but long-term supplementation with leucine alone does not increase muscle mass or strength in older adults.

Do not rely on leucine supplements alone to build muscle. While adding leucine to a small plant-protein meal can make it work as well as a larger animal-protein meal for immediate muscle signaling, taking leucine pills on top of your normal diet has not been shown to increase muscle mass or strength in older adults. Focus on eating enough total protein from whole foods or complete plant proteins instead.