Question 1

How does L-leucine differ from BCAAs?

Accepted Answer

L-leucine is one of three BCAAs (along with isoleucine and valine), but it is the only one that directly activates the mTOR signaling pathway. A BCAA blend typically contains leucine, isoleucine, and valine in a 2:1:1 ratio. Standalone leucine provides greater mTOR activation, while a BCAA blend supports broader recovery.

Question 2

How much L-leucine should I take per day?

Accepted Answer

To maximally stimulate muscle protein synthesis, you need 2-3 grams of leucine per meal. The total daily dose for athletes typically ranges from 5-10 grams. As a standalone supplement, 3-5 grams is often taken immediately after training, especially if the post-workout meal does not contain enough protein.

Question 3

Do I need L-leucine if I already drink protein shakes?

Accepted Answer

Quality whey protein already contains about 2.5 grams of leucine per 25-gram serving. If you drink a protein shake after training, additional leucine may not be necessary. Standalone leucine benefits those using low-leucine proteins (such as plant protein) or wanting to reach the leucine threshold with a smaller meal.

L-Leucine — Key Amino for Muscle Synthesis

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