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Best Leucine Supplements

10 Best Leucine Supplements – Reviewed & Ranked for 2018

If you’re looking for the best leucine supplements to buy this year, then you’ve come to the right place

You can also get more info by jumping to our Leucine Supplements Guide.

Top 10 Leucine Supplements

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#1Bulksupplements Pure L Leucine Powder SBulkSupplements Pure L-Leucine PowderMore Info
#2Micro Ingredients Plant Based Instantized L Leucine Powder SMicro Ingredients Plant-Based Instantized L-Leucine PowderMore Info
#3Source Naturals L Leucine SSource Naturals L-LeucineMore Info
#4Nutrabio 100% Pure L Leucine SNutraBio 100% Pure L-LeucineMore Info
#5Serious Nutrition Solutions Leucine SSerious Nutrition Solutions LeucineMore Info
#6Nutricost Pure L Leucine Powder SNutricost Pure L-Leucine PowderMore Info
#7Allmax Nutrition Leucine Powder SAllmax Nutrition Leucine PowderMore Info
#8Muscle Feast Instantized L Leucine SMuscle Feast Instantized L-LeucineMore Info
#9Now Foods L Leucine Powder SNow Foods L-Leucine PowderMore Info
#10Infinite Labs L Leucine SInfinite Labs L-LeucineMore Info

Leucine Supplements Guide

What is Leucine?

Leucine is one of three branched chain amino acids (BCAAs). Isoleucine and Valine are the other two. BCAAs are necessary for protein synthesis and muscle repair. “Branched Chain” describes the rough shape of a leucine molecule viewed under a microscope.

Each leucine molecule contains a carbon atom chain where one or more carbon atoms connects with three or four more, resembling a branch. Second to glutamine, leucine is the most abundant amino acid in all skeletal muscle.

Leucine is one of nine essential amino acids, which means your body cannot produce it naturally but requires it for a variety of vital purposes and functions. Diet and supplementation are the principle sources of BCAAs, such as leucine.


Leucine has no specific side effects. However, overdosing on amino acids and many other nutrients and cofactors carries the risk of toxicity. Each amino acid has its own toxicity threshold according to your size/weight.

For example, studies suggest that a maximum of 500 milligrams every 24 hours is the toxicity threshold for a 150-pound woman or man. Consuming leucine in excess of this amount results in elevated serum ammonia.

Elevated serum ammonia, or ammonia in the blood, is a prerequisite of muscle fatigue, brain fog and weakness as well as liver or kidney damage or failure.

But there’s a catch. Everybody’s body is different, and we all metabolize protein at different rates based on genes, diet and level of activity. Other sources, such as Livestrong.com, contend that a 196-pound man can tolerate up to 3,700 milligrams of leucine daily, while the toxicity threshold for a 166-pound woman is 3,100 milligrams.

Livestrong.com does not specify its resources for this particular article, so the methodology behind determining these thresholds is questionable.

Always speak with a medical professional or doctor before taking any supplements. Always read the product label for instructions and directions.

Taking Leucine

There are no hard and fast rules on how to take leucine, how much to take or which form is best. Both leucine and BCAA supplements most commonly come in tablet or capsule form, although powders are available.

Tablets and capsules are conveniently self-contained, fitting easily into a small receptacle of your choice. Powders are a little more difficult to manage and require water, mixing and a shaker bottle or glass/spoon.

Leucine powders are most useful for mixing pre-, intra- and post-workout shakes or smoothies for daily maintenance. Since there are many leucine powder products available, both flavored and unflavored, you can stack them with other powdered sports nutrition drinks.

Amino acid toxicity is a real concern, so commence your supplementation with very small doses and increase dosage to assess tolerance. Remember that the more you work out, the greater your protein needs are and the greater your ability to digest and metabolize the protein you consume.

As a result, your ideal daily leucine intake may shift up or down with your level of activity. It’s also a good idea to restrict your leucine supplementation to pre- or post-workout, when the benefits of maximum protein uptake are highest.

What to Look For in a Good Leucine Supplement

Supplements like leucine don’t come with a master list of etched-in-stone qualities to consider. When evaluating supplements, it’s better to consider the manufacturer’s history, reputation, reviews, certifications, awards and other notable supplements that they produce.

Often these characteristics go a long way toward vouching for the quality and efficacy of a supplement your’re thinking about buying.

To gauge the fitness of a supplement company and its products, look for:

  • Past awards from prestigious sports nutrition industry authorities/publications, such as Bodybuilding.com or Muscle & Fitness magazine
  • Certifications, such as GMP, issued from well-known, respected regulatory authorities like the European Medicines Agency, the National Products Association, the National Sanitation Foundation (International) or the International Society for Pharmaceutical Engineering (to to name a few)
  • Reviews and complaints (especially about side effects) from real customers/past users posted to popular online fitness hubs and e-commerce websites

After you complete the above list, you should have a solid idea about a company, its supplements and the particular supplement you’re considering. You’ll also know whether the supplement itself is useful/necessary to your fitness goals or general health.

Important Notice: The information on supplementhound.com is intended for entertainment purposes only and and does not constitute professional, medical or healthcare advice or diagnosis, and may not be used as such. The information on this site is not written, reviewed or endorsed by a medical professional, and is only to be used at your own risk. Make sure to follow label instructions for whichever product you purchase. Supplementhound.com does not assume liability for any actions undertaken after reading this information, and does not assume liability if one misuses products featured on this website. Always consult your doctor before using any products you see on this website. The results may vary about any product effectiveness.