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  • A white bottle labeled NutraBio Leucine contains 180 capsules. Black and green text highlights its role in muscle recovery and support for muscle protein synthesis.
  • Supplement facts label shows 1.6g L-Leucine per 4-capsule serving for muscle recovery and protein synthesis. NutraBio Leucine bottle appears in the lower right, with 45 servings per container.
  • A NutraBio Leucine white supplement bottle label displays the product name, supplement facts, usage directions, and claims such as vegetarian, gluten-free, non-GMO, lactose-free, and supports muscle protein synthesis for recovery.
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L-Leucine

L-Leucine

Build lean muscle, recover well from training, and hold onto your strength as you age with NutraBio L-Leucine. Pure free form leucine in the format that fits your routine, powder or capsules.‡
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L-Leucine
$32.99
$32.99
NUTRABIO QUALITY GUARANTEE

NUTRABIO QUALITY GUARANTEE

Made in the USA • Third-Party Tested • Fully Transparent Labels • Fully Dosed Formulas

Build lean muscle, recover well from training, and hold onto your strength as you age with NutraBio L-Leucine. Pure free form leucine in the format that fits your routine, powder or capsules.‡

Description

How To Use

Key Ingredients

Dietary Restrictions

Delivery & Returns

SKU: 23270
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The Leading Amino Acid for Lean Muscle

Of all the amino acids, leucine is the one your body uses to switch on muscle building and repair. Getting enough of it every day is one of the most direct ways to build lean muscle, recover well from training, and hold onto strength as you age. NutraBio L-Leucine gives you that leucine in its pure free form, fully disclosed on the label and third party tested in every batch, so every serving delivers exactly what it promises.‡

3 g
L-Leucine
Free Form
Amino Acid
ZERO
FIllers or Excipients
100%
Vegetarian

How NutraBio Is Better

Fully transparent labels, no proprietary blends, and third-party testing on every batch — so you always know exactly what you're getting. Here's how NutraBio compares.

A white plastic tub of L-Leucine powder for muscle protein synthesis.NutraBio
A blank white plastic supplement jar with a matching screw-on lid, shown on a clean white background.Other Brands
100% Pure L-Leucine
Naturally Fermented / Vegan
3rd-Party Batch Tested
In-House Manufactured

The Science-Backed Edge

Every ingredient is chosen with purpose and backed by science to deliver meaningful results. Whether it’s wellness or performance, each formula is fully dosed and built with innovation to help your body function at its highest potential.

Live Without Compromise

Live Without Compromise

We are dedicated to helping you achieve real results by ensuring every product is made with the highest-quality ingredients and uncompromising standards. Our commitment to excellence is built to help you reach your potential and live without compromise.

  • Icon showing an arrow pointing upward next to two parallel wavy lines.

    Lean Muscle Growth

    Leucine is the amino acid that activates muscle protein synthesis, giving your body the direct signal it needs to build lean muscle.‡

  • Scroll to top icon featuring two stacked upward-pointing chevrons inside a circle.

    Muscle Maintenance

    Eating fewer calories can put lean muscle at risk. Leucine helps protect the muscle you have worked for while you reach your goals.‡

  • A circular icon featuring a lightning bolt above two wavy lines.

    Muscle Recovery

    Training creates small amounts of muscle breakdown. Leucine supports the repair process so you recover well and feel ready for your next session.‡

  • Scroll to top icon featuring two upward-pointing arrows inside a circle.

    Strength Output

    Muscle naturally becomes harder to build and keep over time. Consistent leucine intake helps maintain the lean muscle and strength that keep you active and independent.‡

  • Line icon of two rising bars in a circle.

    Performance & Strength

    Improves overall training capacity, resilience and performance by optimizing muscle nutrition.

  • A simple black line drawing of a smiling face inside a circular border.

    Support for Plant Based Diets

    Many plant proteins are naturally lower in leucine. Adding pure L-Leucine helps balance a plant forward diet so your protein works harder.‡
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What Pure Leucine Does for You

Lean Muscle

Leucine is the signal your body uses to build and maintain muscle tissue. A daily serving keeps that process working for you.‡

Recovery

Every training session asks your muscles to rebuild. Leucine supports the repair that helps you feel ready to keep going.‡

Lasting Strength

Healthy muscle is one of the biggest factors in how well you age. Keeping it strong now helps you keep doing what you love for years to come.‡

Overall rating: 4.7894735 / 5 from 19 reviews.

AI Generated Review Summary

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Review highlights

Reviews

Great addition for my stack……….

"I add a scoop of this most mornings to my protein shake, seems to be doing what it’s supposed to be doing. Taste is neutral and never a real problem mixing it in the shaker."

— William m. (5/5)

Great product must have

"I really like this product and how it is in powder so I can mix it myself and the price is very affordable. I could not be more happy with it."

— Anthony W. (5/5)

Nothing yet

"No noticeable impact."

— Randolph J. (1/5)

Fast results back up by science

"Leucine is essential when working out and getting the most out of your protein. For better and more efficient results. I will forever buy this product because it works."

— Kimberly (5/5)

building muscle

"one of the best building blocks for muscle building and repair"

— carl p. (5/5)

.

"."

— Naima J. (5/5)

Leucine capsules

"Use it, along with hmb, to slow sarcopenia and to slow deterioration of strength and functionality"

— Lyon (5/5)

GROW

"Great product"

— Lorenzo (5/5)

It can seem like it won't mix in, but

". . . you just have to give it a minute or so. Eventually it will absorb. Very high quality. I'm vegan and need extra leucine. This stuff is perfect."

— Mark (5/5)

Sizable portion

"Using this daily and am going to run it through my system for another month, my weight is up from this and the mass gainer!"

— Jones (5/5)

Q&A

Frequently Asked Questions

What does L-Leucine do?

L-Leucine is an essential amino acid that signals your body to start muscle protein synthesis, the process that builds and repairs muscle tissue. A daily serving supports lean muscle, recovery from training, and maintaining strength over time.

Should I choose the powder or the capsules?

Both deliver pure free form L-Leucine. The unflavored powder is easy to add to a protein shake or smoothie, while the capsules are a convenient option for travel or for anyone who prefers not to mix a drink.

How is L-Leucine different from a BCAA supplement?

BCAA supplements combine leucine, isoleucine, and valine in a set ratio. NutraBio L-Leucine gives you leucine on its own, so you can raise your leucine intake directly or use it alongside a BCAA product.

When should I take L-Leucine?

Follow the suggested use on the label for your format. Many people take it with a meal or protein shake, or around training to support recovery.

Is NutraBio L-Leucine third party tested?

Yes. Every batch is third party tested for purity and potency, and independent lab results are available at CheckMySupps.com.