Rule One Mass Gainer

Energy, Total Fat, Saturated Fat, Cholesterol, Total Carbohydrate, Total Sugars, Includes Added Sugars, Dietary Fiber, Protein, Calcium, Sodium, Potassium, Creatine Monohydrate

United Kingdom & Rest of the World Shipping Details:
Same day dispatch for orders placed by 2pm (Orders after 2pm dispatched 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 14 days in the same original and unopened packaging. Subject to T&C's.

Welzo is a UK-based health platform. Orders ship from the UK.

R1 Mass Gainer should be combined with a high-calorie diet and weight training or other high-intensity exercise. Use R1 Mass Gainer in conjunction with the food you normally eat for additional daily calories. Do not use R1 Mass Gainer in place of meals. For best results, add two heaping scoops (325g) of Mass Gainer with 20-24 oz. of water or milk in a shaker cup or blender and mix it up. You can also mix in a blender with your favourite fruit, a tablespoon of peanut or tree nut butter, and ice for a protein-fortified smoothie. Store in a cool, dry place away from direct sunlight. Keep out of reach of children. Consult a healthcare professional before use if you are pregnant, nursing, taking medication, or have a medical condition.

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

*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

The Active Ingredient Is: Creatine Monohydrate

Creatine monohydrate is a nitrogen-rich compound that helps quick energy generation in muscle cells during intense workouts.

This form is a widely used, well characterised creatine supplement and is commonly added in mass gain mixes to support athletic performance and recovery.

What Does Creatine Monohydrate Do?

Creatine monohydrate helps regenerate ATP, the immediate source of cellular energy, which supports muscle power output during sprinting and resistance workouts; studies indicate strength and muscle gains rise when paired with training.

Dr. Kreider from the University of Arkansas found that creatine monohydrate boosts strength and muscle mass gains in trained folks, matching its role in energy recycling and performance support

This supplement isn't meant to diagnose, treat, cure, or prevent any disease.

Rule One is our go‑to partner for mass gain formulas, drawn around a full and calorie‑dense plan to help hard gainer needs. This brand’s Mass Gainer brings a thoughtful mix of fast‑ and slow‑digesting proteins, a carbohydrate matrix for quick and lasting energy, and creatine monohydrate and BCAAs to support recovery and training intensity. The formulation is built to deliver high calories and substantial protein per serving, in line with Welzo’s emphasis on products that support muscular growth and energy availability.

Rule One has earned credibility in the sports nutrition space through its dedicated focus on weight gain solutions and openness about ingredient composition. This sits in with our rigorous evaluation process, where our team assesses quality, purity, and manufacturing standards. Our review by Welzo's healthcare professionals confirms the brand’s alignment with our ingredient quality and purity standards. This collaboration helps ensure a product that fits both activity demands and Welzo’s safety benchmarks.