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Best Leucine Supplements

10 Best Leucine Supplements – Reviewed & Ranked for 2017

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

#1 Bulksupplements Pure L Leucine Powder S BulkSupplements Pure L-Leucine Powder More Info
#2 Micro Ingredients Plant Based Instantized L Leucine Powder S Micro Ingredients Plant-Based Instantized L-Leucine Powder More Info
#3 Source Naturals L Leucine S Source Naturals L-Leucine More Info
#4 Nutrabio 100% Pure L Leucine S NutraBio 100% Pure L-Leucine More Info
#5 Serious Nutrition Solutions Leucine S Serious Nutrition Solutions Leucine More Info
#6 Nutricost Pure L Leucine Powder S Nutricost Pure L-Leucine Powder More Info
#7 Allmax Nutrition Leucine Powder S Allmax Nutrition Leucine Powder More Info
#8 Muscle Feast Instantized L Leucine S Muscle Feast Instantized L-Leucine More Info
#9 Now Foods L Leucine Powder S Now Foods L-Leucine Powder More Info
#10 Infinite Labs L Leucine S Infinite Labs L-Leucine More 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.

According to a study published in the online Open Access journal Disease Models & Mechanisms, Leucine regulates mTOR, a signaler that activates protein synthesis and spurs/inhibits cellular growth and hypertrophy, especially within favorable nutritional circumstances and during periods of increased mechanical loading (read: consuming protein/nutrients and lifting like a beast).

Bodybuilding.com states that although all BCAAs have mTOR stimulating and regulating properties, Leucine exceeds other BCAAs in this capacity. For this reason, Leucine enjoys a widespread reputation as the “primary” or “main” BCAA.

Hydroxy Methylbutyric acid (HMB) is a product (or metabolite) of metabolized leucine. HMB is naturally anti-catabolic, which means it minimizes/prevents the breakdown of muscle. Compared to leucine on a gram-by-gram basis, HMB is a more potent/effective anti-catabolic substance, but HMB lacks leucine’s powers to activate protein synthesis. It’s notable that the body requires leucine as a chemical precursor without which your body cannot produce HMB.

Benefits of Leucine

Leucine essentially flips your muscle growth switch. Studies indicate that drenching your muscles with a leucine and whey protein mixture is the biological flag that puts your protein synthesis into “go” mode.

In particular, a 1.25:1 ratio of whey protein to leucine heavily contributes to optimal anabolic conditions within the body, the type of conditions in which mTOR activates and explosive muscle growth begins.

Leucine has such marked protein-synthesis potential and anti-catabolic properties via HMB that doctors use it to treat muscular wasting associated with diseases like cancer, states Examine.com.

Leucine increases insulin sensitivity, helping your body to maximize glucose metabolism. Increased insulin sensitivity has many of its own corresponding benefits, such as improved energy, fewer hungers pangs and glucose-related mood swings, better hormonal interactions and maximum uptake of nutrients, cofactors, protein and amino acids.

Better still, leucine positively affects the manner in which improved insulin sensitivity acts on multiple levels of metabolism. What does this mean? It means that leucine supplementation effectively reverses the ill health outcomes of insulin insensitivity, such as obesity, decreased muscle and fatty liver, according to a study published in the journal of the Public Library of Science.

Consuming leucine between meals accelerates recovery and protein synthesis, which means you make gains throughout the day, hovering powerfully in an anabolic state. Individual results vary according to genetics, diet and workout intensity.

Leucine is a basic building block of “buffer” proteins. Buffer proteins bind to acids and toxic metabolites, such as lactic acid and ammonia, that build up in your muscle during routine protein breakdown and mechanical loading. It’s these metabolites and acids that cause fatigue and soreness.

By binding to toxic metabolites and acids, buffer proteins “spring-clean” your muscles, delaying fatigue and greatly minimizing soreness. With your muscles spring-cleaned, you recover faster and bounce back between workouts more quickly.

During the same series of processes, leucine restores your body’s nitrogen balance. When you’re body takes in more nitrogen than it releases, you’re effectively living in a perpetually anabolic state, a state of constantly building muscle.

Bear in mind that you have to be working out hard and eating a comprehensive diet in order for growth to occur. Leucine supplementation ensures that you maximize your inherent anabolic potential.

Evidence suggests that leucine may promote longevity at the cellular level. Its metabolite HMB activates SIRT1 and 5’adenosine monophosphate-activated protein kinase. The former is a protein that induces mitochondria to produce more cellular energy. The latter is an enzyme that aids in the transfer of cellular energy to specified molecules.

In laymen’s terms, leucine keeps you young at the cellular level, staving off the energy:mass deficit and cellular degradation that is generally common to the aging process, so says a study published on Hindawi.com, the online home of the Open Access Journal of Nutrition and Metabolism.

Are There Any Side Effects?

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.

How to Take 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.

Note: Always speak with your doctor before taking any supplements featured on this website. This article has not been written, reviewed or endorsed by a medical professional and may not be used to diagnose or treat any medical conditions.