Best Protein Powder for Bulking (UK 2026)

The best protein powder for bulking is one that delivers plenty of protein and the extra calories you need to build muscle and put on mass quickly. That second part is what separates a bulking protein powder from an everyday whey or plant blend: a standard scoop lands around 100 to 130kcal, which barely dents the surplus you are trying to eat. If you're looking to push through plateaus in the gym during a bulking phase, this is our breakdown of the best bulking protein powders available in the UK today.

We researched the most popular plant-based bulking powders on Amazon UK rather than testing them ourselves, comparing protein per serving, calories, ingredients and price against the manufacturers' own figures. Below you'll find an overview of each, the pros and cons, and where to buy them. Whey gainers aren't in the line-up, and there's a section further down explaining when dairy is the better call.

Bulk Vegan Mass Gainer: Best overall for bulking

The Bulk Vegan Mass Gainer is an affordable vegan protein powder that comes in a massive 2.5kg bag and delivers 30g of plant-based protein and 367kcal per serving, making it our top all-round pick for adding mass.

It's made from pea, brown rice and pumpkin seed protein, combined with vitamins and minerals to help the body recover after big training sessions. It also packs over 40g of complex carbohydrates while keeping sugar content low. You can choose from a range of flavours, including Chocolate Peanut, Strawberry and Banana Caramel.

• Premium, high-quality vegan mass gainer from a leading sports nutrition brand
• 367kcal and 30g of protein per serving, high in fibre and low in sugar
• No artificial sweeteners, colourings or flavourings, for a natural taste, gluten and soya free
• Environmentally friendly, compostable packaging
• Available in a range of flavours

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Protein Works Vegan Mass Matrix 360: Highest calorie content

Protein Works Vegan Mass Matrix 360, which the brand previously sold as Vegan Mass Gainer Extreme, is the biggest calorie hit on this list, providing up to 51g of protein and up to 770kcal per serving. It's made using a tri-protein blend of soy isolate, pea isolate and brown rice concentrate, giving a complete amino acid profile from a good mix of plant sources.

A long-standing rule of thumb puts roughly 3,500kcal to a pound of body weight, which works out at about 500kcal a day above your maintenance level (the calories needed to neither gain nor lose weight). Treat that as a starting point rather than a law. A review of the evidence concluded that an energy surplus does provide an anabolic stimulus, but that the specific surplus needed to maximise muscle growth is still unknown, and that textbook calculations tend to ignore the other energy costs of building tissue (Slater et al., 2019). At up to 770kcal a serving, this is a serious mass builder for anyone looking to bulk.

The honest catch is the serving size behind those headline numbers. A serving is a hefty 200g, which is why a 2kg bag holds only 10 of them, so the real cost per serving is a lot higher than the bag price suggests and plenty of people will find a full serving hard to get down in one go. Treat it as a way to add a big block of calories on heavy training days rather than as an everyday shake.

• 100% plant based
• Up to 770kcal and up to 51g of protein per serving
• Tri-protein blend (soy isolate, pea isolate and brown rice concentrate) for a complete amino acid profile
• 15% of the daily recommended intake of calcium, vitamin C, B5, B6, B9 and B12 per serving
• 2kg bag holding 10 servings, sold in a choice of flavours

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Vivo Life Perform Vegan Protein: Best balanced all-rounder

Vivo Life Perform Vegan Protein is a well-balanced powder built on a blend of fermented yellow pea and cold-pressed hemp protein. It delivers 25g of protein and 6g of BCAAs per serving, and Vivo Life says the blend covers all nine essential amino acids, which is the thing to look for in a plant protein.

It isn't a mass gainer, and that's exactly why it's here. Perform is a clean everyday protein rather than a calorie bomb, so it suits a bulk where you'd rather get the calorie surplus from real food and use the shake to top up your protein. Two servings takes you to 50g of protein, which turns a balanced everyday shake into a genuine bulking one. The honest catch is that doing that gets through a tub quickly, because the 26 servings become 13, and Perform is priced as a premium everyday protein rather than a cheap bulk of calories. Flavours include Chocolate Brownie and Salted Caramel.

• 25g of protein and 6g of BCAAs per serving, covering all nine essential amino acids
• Fermented yellow pea and cold-pressed hemp protein, plus a digestive enzyme blend of ginger, papain, peppermint leaf and black pepper
• 150mg of organic turmeric extract per serving, standardised to 95% curcuminoids
• A natural source of iron, zinc and selenium
• Certified by the Vegan Society, gluten free and made in the UK
• Each batch third-party tested for heavy metals and contaminants

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The three bulking powders compared

Calories per serving is the number that matters here, and the serving sizes are not comparable, which is where most comparisons go wrong.

Read that table with the serving size in mind. Mass Matrix 360 looks twice the powder of the Bulk gainer because the serving is roughly twice the size, so per 100g the gap narrows considerably, and a 2kg bag holding 10 servings runs out faster than the price tag suggests.

Which bulking protein powder should I buy?

If your goal is a powder focused purely on bulking, we'd recommend the Bulk Vegan Mass Gainer. It's designed specifically to be a mass-gaining protein.

If you want the biggest calorie hit you can get in one shake, go for the Protein Works Vegan Mass Matrix 360. If you'd prefer something more balanced with additional benefits such as BCAAs, which you can scale up with a second scoop, consider Vivo Life Perform.

Whey or vegan for a bulking protein powder?

Worth saying plainly, given all three powders above are plant based: whey does the job just as well. Total daily protein and total daily calories are what drive the result, and a whey gainer hits both without complaint. This guide went plant based because that's the corner of the market it researched, not because dairy is the weaker choice.

If you'd rather buy dairy, our best mass gainer UK guide covers the high-calorie whey blends, and our best protein powder UK round-up covers ordinary whey that you can simply take two scoops of. That second route usually works out cheaper per calorie than a dedicated gainer, since you aren't paying a supplement-brand premium for maltodextrin that a bowl of oats provides for pennies.

What is bulking?

Bulking is the process of gaining weight in order to increase muscle mass. The goal isn't just to gain weight, but to increase strength levels at the same time.

A bulk should only last a set period of time, typically fairly short. We suggest six weeks at most, with longer rest periods between each bulk cycle.

Protein powder can be a useful part of any bodybuilder's diet, but not all powders are suitable for bulking. That's why the three plant-based powders above are chosen specifically for building muscle mass.

How do I bulk with protein powder?

If you want to use protein powder to help you bulk, the key is choosing the right one for your goals. Not all powders are made equal, so it's worth doing your research on what different bulking powders offer before committing. Fortunately, we've done the hard work for you above.

To follow a successful bulking plan, your diet needs to be on point first. Protein powder should complement your diet, not be the main act.

1. Calculate your BMR (your resting calorie requirements). There are plenty of free calculators online. A typical person's BMR is usually between 2,000 and 2,500 calories per day.
2. Eat above your BMR, but not by too much, otherwise you'll pile on excessive fat. A good starting point is around 2,500 to 3,000 calories per day, depending on your sex, weight and age.
3. Track your calories and macros. MyFitnessPal is a free app that makes this easy. It also helps you see how much energy you have available for exercise. Some people find it helpful to break their food into three to five smaller meals throughout the day.
4. Lift weights regularly. Bulking and lifting go hand in hand, and you can't build serious muscle mass without it. Aim to train each muscle group at least twice a week when bulking.

When bulking, your lifts should increase steadily. If they aren't, revisit your training regime and look at how often, and how much, you're lifting each week.