Leucine Benefits & Side Effects

Leucine is one of the three essential branch-chain amino acids that includes Isoleucine and Valine.

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.

References
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.

Travis Hlavka (9 Posts)

I may act like a 12yr old a lot of the time, but that's because I have a genetic defect that will not allow me grow up. HOWEVER, I do take strength training and fitness very seriously and I love using what I know to help others reach their fitness goals and avoid the bazillion mistakes I've made in my 25+ yrs of training. Since I don't know everything, I never stop learning. Note: I am no longer a "certified" trainer, but I truly understand more about fitness and health now than I ever did with that official piece of paper.