Vegan BCAAs: Don't Eat Human Hair and Duck Feathers

Branched-Chain Amino Acids

Ah yes, workout supplements. They make you strong and sexy


The supplement in today's topic are BCAAs. Most are made out of human hair or duck feathersR


  1. Basics
  2. Benefits
  3. Glucose Metabolism
  4. Cons
  5. Buy BCAAs
  6. When to Use BCAAs
  7. More Research








A BCAA is an amino acid having aliphatic side-chains with a branch (a central carbon atom bound to three or more carbon atoms). Among the proteinogenic amino acids, there are three BCAAs: leucine, isoleucine and valine. R

Enzymes involved are branched chain aminotransferase and 3-methyl-2-oxobutanoate dehydrogenase.

Enzymes involved are branched chain aminotransferase and 3-methyl-2-oxobutanoate dehydrogenase.


Degradation of branched-chain amino acids involves the branched-chain alpha-keto acid dehydrogenase complex (BCKDH). Degradation of branched-chain amino acids involves the branched-chain alpha-keto acid dehydrogenase complex (BCKDH). R


1. Triggers Muscle Protein Synthesis


Leucine, one of the amino acids in BCAAs, can active the mTOR pathway. R 

mTORC1 activation is required for myofibrillar muscle protein synthesis and skeletal muscle hypertrophy in response to both physical exercise and ingestion of certain amino acids or amino acid derivatives. R R

So after a hard workout, supplementing with Leucine may increase your muscle mass...word

2. Increases Exhaustion Time

In untrained or lightly train individuals, the time to get to exhaustion was longer when supplementing BCAAs. R R R R

During cycling, there was a 17.2% increased time to exhaustion with supplementing BCAAs. R

Supplementing BCAAs during a a marathon may help slower runnersR

3. May Decrease Fatigue

Mental fatigue after workouts were reduced when receiving BCAAs. R R R R R R R R

BCAA supplementation increased resistance to fatigue. R

Glucose Metabolism


Valine and Isoleucine can be converted into glucose in the body, if needed. R

Leucine can hinder cellular glucose uptake through activaiton of mTOR signaling, which can suppress AMPK signaling. R R R R

mTOR hinders IRS-1 (Insulin receptor substrate 1) signaling, through the activation of S6K1 (Ribosomal protein S6 kinase beta-1). R R

Valine (30 minutes) is faster than Leucine (90 minutes) at inhibiting glucose uptake into muscle cells. R

Isoleucine does not increase glycogen synthesis. R

BCAAs preserve hepatic and skeletal muslce glygoen stores after exercise. R R

Insulin Resistance


Leucine, in theory, can exacerbate insulin resistance. R

In rats, leucine deprivation and high leucine feeing improves insulin resistance. R R


Consumption of BCAAs may be unnecessary and possibly harmful. R

It may increase fat oxidation. R R R


It may increase ammonia in the brain. R

Ammonia is a possible promoter of muscle breakdown induced fatigue. R R

In rats R

  • Increasing BCAAs to 3.57% for 6 weeks improved exercise by reducing ammonia production  by 37%. 
  • Increasing BCAAs to 100% reversed this, impairing exercise and increasing ammonia production by 43%. 



In my interview with Geoff Palmer, we talked about how BCAA's are made of human hair and duck feathers. Here are some that aren't:

Cannabalism is bad.

When to Use BCAAs

Gabrielle Lyon, DO, recommends to start an exercise with a high amount of carbs, then after the workout (when your muscles are primed) to tkae BCAAs (or leucine). Since the proteins are primed, you can use less protein. The more older you are, the more protein you need. 

More Research

  • Intermittent mTOR activation in prefrontal neurons by β-hydroxy β-methylbutyrate inhibits age-related cognitive decline associated with dendritic pruning in animals, which is a phenomenon also observed in humans. R
  • During soccer, BCAA may help with reaction time. R