Applied Nutrition Leucine powers quick muscle protein building and faster recovery, because it’s top-notch, pure leucine delivered in a Halal-certified and Informed-Sport checked formula

Manufactured in ISO 22000, BRC and GMP accredited facilities, the product is Halal certified and Informed-Sport tested for athlete peace of mind

This heritage focus and strict quality controls set Applied Nutrition Leucine apart

Available Sizes & Variants:

180 capsules – convenient daily supply for steady leucine intake.

Benefits & Features:

• Supports muscle growth and faster post workout recovery
• Intended for daily use, delivering a pure leucine amino acid for targeted protein synthesis within a protein powder for muscle gain routine
• Quality assured with ISO 22000, BRC and GMP standards, and Halal certification
• Leucine amino acid star ingredient optimises the mTOR pathway to trigger muscle repair and growth after training
• Informed-Sport tested, you can trust this product is free from banned substances and suitable for athletes

Applied Nutrition has built a long standing reputation among athletes for pure, reliable supplements. Leucine 4K uses only L-Leucine, a rice flour bulking agent and a plant capsule, manufactured in ISO 22000, BRC and GMP accredited facilities. Halal certified and Informed-Sport tested, this leucine amino acid formula is designed for daily use and trustworthy performance. For a complete training stack, it blends smoothly with best creatine for women.

L-Leucine, Bulking Agent (Rice Flour), Capsule (Hydroxypropyl Methylcellulose, Colour (Brilliant Blue),

• GTIN: 5056555205396
• Manufacturer: Applied Nutrition
• Categories: Applied Nutrition ProductsLeucine SupplementsSports Supplements
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Consume 1-2 servings daily, preferably with food. For optimal results on training days, take one serving 45 minutes prior to exercise and one serving post-exercise. Store in a cool, dry place out of reach of young children. Check with a qualified health professional before using this product if you are nursing a baby or if you have any known or suspected medical condition(s) or are taking any prescription or OTC medications. Not to be used as a substitute for a varied diet and healthy lifestyle. Not recommended for children or pregnant women. Do not use if under the age of 18 years old. Do not exceed the recommended dosage.

Please consult the product packaging for accurate instructions on how to use the product.

The Active Ingredient Is: Leucine

Leucine is an essential amino acid that occurs naturally in protein-rich foods and is a fundamental building block for muscle tissue. This product delivers pure L-Leucine in a plant-based capsule formulation.

What Does Leucine Do?

Leucine helps activate muscle protein synthesis via the mTOR pathway, which supports muscle growth and recovery after exercise. It also helps maintain lean body mass during weight loss or ageing, a role supported by clinical evidence on amino acid metabolism.

This product isn’t intended to diagnose, treat, cure, or prevent any disease.

L-Leucine: 4000 mg

Applied Nutrition kicks off with a science backed take on amino acid nutrition, and that strict formulation vibe is why we decided to team with them for Leucine 4K. The brand's commitment to purity and potency shines through its fill of premium L-Leucine packed in a plant-based capsule, reflecting a careful manufacturing mindset that lines up with Welzo's standards. The maker runs in ISO 22000, BRC and GMP approved sites, with Halal certification and Informed-Sport testing, keeping strict quality controls for athletes and active folk. That level of oversight helps trust and safety across batches, a real cornerstone of how we pick partners. For our medical team's check on product integrity, we lean on these certifications and their clear focus on purity and safety, which you can explore via our medical team and our ingredient quality and purity standards.

Applied Nutrition's evidence backed approach highlights leucine's job in kicking muscle protein synthesis, which makes the brand a sensible fit for a product built to support athletic recovery and lean muscle maintenance. This brand sticks out against rivals thanks to its solid quality framework and sport-safety credentials, lining up perfectly with the product's targeted use. Welzo's evaluation process emphasizes rigorous science and supplier reliability, helping this pairing deliver both performance and safety for customers.