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Muscle Gain

Collection: Muscle Gain

Build size, strength and lean muscle with our premium muscle gain supplements at The Box Supplements. Whether you're looking for high-quality whey protein, mass gainers, creatine or intra-workout support, we stock trusted brands to help maximise muscle growth and recovery. Ideal for beginners and advanced lifters alike, our muscle-building range is designed to support progressive overload, improved recovery and consistent results. Shop muscle gain supplements in the UK with fast delivery and outstanding customer service.

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1792 products

Bulk Pure Whey Protein 450g Vanilla

Bulk Pure Whey Protein 450g Vanilla

Regular price £16.99
Sale price £16.99 Regular price
Bulk Complete Breakfast Smoothie 500g Strawberry & Banana

Bulk Complete Breakfast Smoothie 500g Strawberry & Banana

Regular price £14.99
Sale price £14.99 Regular price
Applied Nutrition Critical Whey 2kg White Choc Pistachio

Applied Nutrition Critical Whey 2kg White Choc Pistachio

Regular price £55.99
Sale price £55.99 Regular price
Applied Nutrition Critical Whey 2kg Frappuccino

Applied Nutrition Critical Whey 2kg Frappuccino

Regular price £55.99
Sale price £55.99 Regular price
Applied Nutrition Critical Whey 2kg Chiquita Banana Strawberry Smoothie

Applied Nutrition Critical Whey 2kg Chiquita Banana Strawberry Smoothie

Regular price £55.99
Sale price £55.99 Regular price
Per4m Whey Hydrate 900g Strawberry Watermelon

Per4m Whey Hydrate 900g Strawberry Watermelon

Regular price £40.99
Sale price £40.99 Regular price
Per4m Whey Hydrate 900g Orange and Pineapple

Per4m Whey Hydrate 900g Orange and Pineapple

Regular price £40.99
Sale price £40.99 Regular price
Per4m Whey Hydrate 900g Blueberry Peach

Per4m Whey Hydrate 900g Blueberry Peach

Regular price £40.99
Sale price £40.99 Regular price
Vilgain Grass-fed Whey Protein 1000g Chocolate

Vilgain Grass-fed Whey Protein 1000g Chocolate

Regular price £32.99
Sale price £32.99 Regular price
UFIT Protein RTD 8x500ml White Chocolate

UFIT Protein RTD 8x500ml White Chocolate

Regular price £24.99
Sale price £24.99 Regular price
UFIT Protein RTD 8x500ml Chocolate

UFIT Protein RTD 8x500ml Chocolate

Regular price £24.99
Sale price £24.99 Regular price
Trek Protein Flapjack 16x50g Cocoa Coconut

Trek Protein Flapjack 16x50g Cocoa Coconut

Regular price £22.99
Sale price £22.99 Regular price
Trek Protein Flapjack 16x50g Cocoa & Oat

Trek Protein Flapjack 16x50g Cocoa & Oat

Regular price £22.99
Sale price £22.99 Regular price
Trained By JP Performance Protein 2kg Caramel Fudge

Trained By JP Performance Protein 2kg Caramel Fudge

Regular price £47.99
Sale price £47.99 Regular price
The Skinny Food Co High Protein Croissants 50g Original

The Skinny Food Co High Protein Croissants 50g Original

Regular price £5.99
Sale price £5.99 Regular price
The Skinny Food Co High Protein Croissants 50g Chocaholic

The Skinny Food Co High Protein Croissants 50g Chocaholic

Regular price £5.99
Sale price £5.99 Regular price
Shaken Udder Milkshake 8x330ml Chocolush

Shaken Udder Milkshake 8x330ml Chocolush

Regular price £19.99
Sale price £19.99 Regular price
Shaken Udder Protein Milkshake 8x330ml White Chocolate

Shaken Udder Protein Milkshake 8x330ml White Chocolate

Regular price £22.99
Sale price £22.99 Regular price
CNP Whey 2kg Sticky Toffee Pudding

CNP Whey 2kg Sticky Toffee Pudding

Regular price £49.99
Sale price £49.99 Regular price
CNP Whey 900g Chocolate

CNP Whey 900g Chocolate

Regular price £29.99
Sale price £29.99 Regular price

FAQ's

How long will delivery take?

We ship via DPD Next Working Day for orders placed before 3pm. Please allow 1 working day for order handling and dispatch, plus 1 working day transit.

How long do I have to return an item?

You have 30 days from the date you receive your order to return any items.

What happens if I order after the 3pm cut-off?

Orders placed after 3pm will enter our handling queue the next working day, and you’ll then need 1 working day for processing plus the usual 1 working day for DPD delivery.

How do I start a return?

Simply fill out the Customer Returns Form and we’ll send you the return instructions.