Leucine Benefits & Side Effects

The information below was gathered from several different sites across the world of the wide webs.  With that said, I HIGHLY RECOMMEND READING Examine.com’s research on Leucine.  They have the most comprehensive scientific supplement data I have ever seen and I trust it above all other sites out there!

Leucine is one of the three essential branch-chain amino acids that includes Isoleucine and Valine.  (Best prices I’ve found are here at AllStarHealth).

It aides in producing energy, and regulating muscle repair, growth, and blood sugar. Leucine is usually given to post-surgery patients to prevent the loss of muscle during recovery.

Leucine stimulates protein synthesis in the muscle. Research implies that protein synthesis may be more efficient with plain leucine than with a complete BCAA supplement because leucine absorbs more quickly. The more leucine, the more protein synthesis, theoretically.

You are most likely receiving enough leucine if you eat beef and poultry, or dairy products such as milk and eggs. Fish also contains Leucine.

Leucine Dosing

  • Leucine powder is meant to be mixed with liquid and consumed twice daily. Especially after working out.
  • The Allmax Nutrition Leucine powder that I take recommends two 5g servings/day. I have been taking about 10g in my homemade pre workout drink and then 2.5g after as part of my BCAA’s.

Leucine Benefits

  • Like other essential amino acids, it helps maintain muscle mass.
  • Weight Loss Benefits
  • Cholesterol Level Reduction

Leucine Side Effects

Excessive Leucine has been reported to cause:

  • Hypoglycemia, marked by weak motor control, a loss of awareness, extreme forgetfulness, and subsequent loss of consciousness.
  • Ammonia accumulation which can lead to liver and kidney failure if not addressed
  • Pellagra (Vitamin B3 deficiency)
  • Allergic reactions such as swelling, itchy or rashes.

The Journal of Physiology
Livestrong – Leucine Muscle Growth
Livestrong – Leucine Benefits
Livestrong – Leucine Side Effects
Livestrong – Leucine Powder
Ray Sahelian, MD
PubMed – Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men.