Applied Nutrition Critical Mass Professional is one of the most advanced mass gainers available in the UK right now. But with a premium price tag and a long ingredient list, is it actually worth it — and is it the right choice for your goals?

We stock Critical Mass Professional at Muscle Products Store and have put it through its paces properly. This review covers everything you need to know — the ingredients, the macros, the taste, the mixability, who it’s best for, and whether it lives up to its reputation as the UK’s go-to mass gain supplement.

Quick Verdict

What Is Applied Nutrition Critical Mass Professional?

Critical Mass from Applied Nutrition has long been regarded as one of the UK’s most trusted mass gain supplements. The Professional formula is the upgraded version — a revamped, more advanced formula that reduces sugar content while adding a significantly more comprehensive ingredient profile designed for serious lean mass development.

This is not a simple protein-plus-carbs shake. Critical Mass Professional is a fully loaded performance formula built around a premium multi-source protein blend, a dual creatine matrix, muscle preservation and recovery compounds, digestive support, and even probiotics. For anyone serious about building lean muscle with a mass gainer that goes beyond the basics, this is one of the most complete options available in the UK market.

Macros & Nutritional Breakdown

Per serving (2 scoops / approximately 240g):

• Protein: 42g
• Carbohydrates: 74g
• Fat: 10g
• Sugar: Reduced — new lower sugar formula
• Salt: 0g

The macro split is well balanced for lean mass building. The 42g protein content is among the highest per serving of any mass gainer on the UK market, and the carbohydrate content is substantial enough to support glycogen replenishment and recovery post-workout without being excessively high.

Mixing with full-fat milk rather than water will add approximately 150–200 additional calories, making this a flexible formula that suits both moderate and more aggressive calorie targets.

Ingredient Breakdown — What Makes It Professional Grade?

This is where Critical Mass Professional genuinely stands apart from most mass gainers on the market. The ingredient list goes well beyond a basic protein and carbohydrate blend.

Premium Multi-Source Protein Blend

The protein matrix combines three distinct sources for optimal absorption across different timeframes:

ISO-XP™ 95% Whey Protein Isolate — a premium, fast-absorbing whey isolate with a high protein percentage per gram. Ideal for immediate post-workout muscle protein synthesis.

MPI 90 Milk Protein Isolate — a slower-digesting protein that provides sustained amino acid release over several hours. Particularly effective when taken before bed for overnight muscle recovery and growth.

WPC 80 Whey Protein Concentrate — a cost-effective, well-rounded protein source that bridges fast and slow absorption profiles.

The combination of fast, medium, and slow-releasing proteins means your muscles receive a sustained supply of amino acids — not just an immediate spike. This is exactly what you want from a mass gainer taken around workouts or before bed.

Dual Creatine Matrix

Creatine Monohydrate (3g) — the gold standard creatine form, backed by decades of research. Supports strength, power output, and muscle growth.

Kre-Alkalyn® Buffered Creatine Monohydrate (2g) — a pH-buffered creatine designed to improve stability and reduce conversion to creatinine before it reaches muscle cells. A premium addition that goes beyond what most mass gainers offer.

The combination of both forms means you get the proven results of monohydrate alongside the enhanced stability of Kre-Alkalyn® — providing comprehensive creatine support in a single serving.

Muscle Preservation & Recovery Complex

HMB (Beta-Hydroxy Beta-Methylbutyrate) — a metabolite of leucine that has been shown to reduce muscle protein breakdown, particularly during periods of intense training. Helps preserve lean muscle during aggressive bulking phases.

L-Leucine — the most anabolic of the essential amino acids. Directly triggers muscle protein synthesis and is critical for muscle growth signalling.

Glutamine Peptides — supports muscle recovery, reduces post-workout soreness, and supports immune function during heavy training.

HICA (Alpha-Hydroxy Isocaproic Acid) — an anti-catabolic compound that further supports muscle preservation during intense training phases.

Performance & Absorption Support

AstraGin™ (Astragalus & Panax Notoginseng Extract) — a patented absorption-enhancing complex clinically shown to improve the uptake of amino acids, creatine, and other nutrients. Every gram of protein and creatine in this formula works harder because of this ingredient.

ALA (Alpha Lipoic Acid) — supports insulin sensitivity and nutrient partitioning, helping carbohydrates and amino acids be directed toward muscle cells rather than fat storage.

Chromium Picolinate — contributes to normal macronutrient metabolism and helps optimise energy utilisation from the carbohydrates in each serving.

Digestive Health Support

DigeZyme™ Enzyme Complex (Amylase, Protease, Cellulase, Lactase, Lipase) — a comprehensive multi-enzyme blend that supports the breakdown and absorption of proteins, carbohydrates, and fats. Reduces the digestive discomfort that high-calorie shakes can cause.

LactoSpore™ Probiotics (Bacillus Coagulans) — a clinically studied probiotic strain that supports gut health and digestive function. An unusual and impressive addition that very few mass gainers include.

Healthy Fat Sources

CLA (Conjugated Linoleic Acid) — supports lean body composition and has been studied for its role in reducing fat accumulation during calorie surplus phases.

MCT (Medium Chain Triglycerides) — fast-absorbing healthy fats that provide quick energy and support hormonal health. Preferable to saturated fats as a calorie source in a mass gainer formula.

Pterostilbene — a natural antioxidant compound related to resveratrol, supporting recovery and general health during heavy training phases.

Carbohydrate Sources

Organic Ground Oats — a slow-releasing, low glycaemic index carbohydrate that provides sustained energy and contributes to the reduced sugar profile of the Professional formula.

Maltodextrin — a fast-acting carbohydrate that rapidly replenishes glycogen stores post-workout, supporting quick recovery and muscle fullness.

The combination of slow and fast carbohydrates mirrors the approach of the protein blend — sustained delivery rather than a single spike.

Taste & Mixability

Customer feedback on taste and mixability is consistently positive. One verified customer described it as “easy to drink and very nice taste” — and this matches the experience most users report with Applied Nutrition products.

The inclusion of DigeZyme™ digestive enzymes and LactoSpore™ probiotics means this formula is specifically designed to be gentle on digestion — addressing one of the most common complaints with high-calorie mass gainers. No bloating, no discomfort, just clean calorie delivery.

Mixing: 2 scoops with 500ml of water or milk in a standard shaker. Adjust liquid volume to achieve your preferred consistency. Mixes cleanly with no significant clumping.

Flavours available: Multiple options to suit different preferences — making daily compliance easy and enjoyable.

Who Is Applied Nutrition Critical Mass Professional For?

Hard-gainers and fast metabolisms — The high calorie and protein content makes this an effective daily tool for anyone struggling to hit a consistent surplus through food alone.

Anyone focused on lean mass — The reduced sugar formula, CLA, ALA, and chromium content all support lean muscle development rather than indiscriminate weight gain.

Experienced lifters in a serious bulking phase — The professional-grade ingredient stack — dual creatine, HMB, AstraGin™, DigeZyme™ — goes well beyond what beginners need and is designed for those who want every nutritional advantage.

Anyone with digestive sensitivity — The DigeZyme™ enzyme complex and LactoSpore™ probiotics make this one of the most gut-friendly mass gainers available, particularly suitable for those who have experienced discomfort with other high-calorie formulas.

Muslim customers — Critical Mass Professional is Halal certified, making it one of the few premium mass gainers in the UK that is suitable for Muslim athletes.

How to Take Applied Nutrition Critical Mass Professional

Standard serving: Mix 2 scoops (approximately 240g) with 500ml of water or milk.

Timing options:

• Post-workout — the fast-absorbing ISO-XP™ whey isolate and maltodextrin work together to support immediate recovery and glycogen replenishment after training
• Before bed — the milk protein isolate component provides slow-releasing amino acids throughout the night, supporting overnight muscle repair and growth
• Between meals — use as a calorie top-up on both training and rest days to maintain your daily surplus consistently

Adjust to your goals: Mix with full-fat milk instead of water for additional calories. Use a larger liquid volume for a thinner shake, or less liquid for a thicker, more filling consistency.

Consistency is key: Like all mass gainers, Critical Mass Professional works through daily habitual use — not occasional supplementation. Build it into your routine at the same time each day.

Applied Nutrition Critical Mass Professional vs Critical Mass Original — What Is the Difference?

Both products are from Applied Nutrition and both are excellent mass gainers. Here is how they compare:

Critical Mass Professional features the upgraded formula with reduced sugar, ISO-XP™ 95% Whey Protein Isolate, dual creatine matrix (Monohydrate + Kre-Alkalyn®), HMB, AstraGin™, DigeZyme™, LactoSpore™ probiotics, and Pterostilbene. It is the more advanced, comprehensive formula designed for serious lean mass development.

Critical Mass Original delivers over 900 calories per serving with 55g of premium dairy protein, L-Glutamine, CLA, Bromelain digestive enzyme, and naturally occurring BCAAs and EAAs. It is the higher-calorie option best suited to very fast metabolisms and aggressive bulking phases.

Which should you choose?

Choose Critical Mass Professional if you want a cleaner, leaner formula with a more advanced ingredient profile — particularly the dual creatine matrix, HMB, and digestive support complex.

Choose Critical Mass Original if maximum calories per serving is your priority and you need the most aggressive calorie support available.

Both are stocked at Muscle Products Store with fast UK delivery.

Pros and Cons

Pros:

• Exceptionally comprehensive ingredient profile — goes far beyond a standard mass gainer
• 42g protein per serving from a premium multi-source blend including ISO-XP™ 95% whey isolate
• Dual creatine matrix — monohydrate plus Kre-Alkalyn® in a single serving
• DigeZyme™ and LactoSpore™ for superior digestive comfort
• AstraGin™ for enhanced nutrient absorption
• Reduced sugar formula for leaner gains
• Halal certified
• 6kg tub — 25 servings — excellent value at £59.99
• Outstanding taste and easy mixability

Cons:

• Lower total calories per serving than Critical Mass Original — not ideal for those who need maximum calorie volume above everything else
• Premium formula means a higher price point than basic mass gainers
• Large 6kg tub — storage space required

Customer Reviews

⭐⭐⭐⭐⭐ Eric Green — Verified Purchase “Top mass gainer easy to drink and very nice taste.”

Rated 5 out of 5. Applied Nutrition Critical Mass Professional is currently rated 5/5 based on customer reviews at Muscle Products Store.

Final Verdict — Is Applied Nutrition Critical Mass Professional Worth It?

Yes — and for the right buyer, it is one of the best mass gainers available in the UK.

The ingredient profile is genuinely impressive. Most mass gainers deliver protein, carbohydrates, and perhaps some creatine. Critical Mass Professional delivers all of that plus HMB, AstraGin™ for enhanced absorption, DigeZyme™ for digestive comfort, LactoSpore™ probiotics, dual creatine, CLA, MCTs, and more. This is a formula that has been thought through properly — not just a high-calorie shake with a long ingredient list for marketing purposes.

At £59.99 for 6kg and 25 servings, the price per serving is also competitive for a formula of this quality. If lean mass development, digestive comfort, and a comprehensive performance ingredient stack are your priorities, Critical Mass Professional is very hard to beat in the UK market.

Overall rating: 5/5 ⭐⭐⭐⭐⭐

[👉 Shop Applied Nutrition Critical Mass Professional 6kg — £59.99]

Frequently Asked Questions

Is Applied Nutrition Critical Mass Professional good for beginners? Yes. The formula is comprehensive but the usage is straightforward — mix and drink. Beginners benefit from the creatine, protein blend, and digestive support just as much as experienced lifters.

Is Critical Mass Professional Halal? Yes. Applied Nutrition Critical Mass Professional is Halal certified, making it suitable for Muslim athletes and one of the few premium mass gainers in the UK with this certification.

How many calories are in Critical Mass Professional? Approximately 550–600 calories per serving with water. Mixing with full-fat milk adds approximately 150–200 additional calories per serving.

Can I take Critical Mass Professional before bed? Yes — Applied Nutrition specifically recommend this as an option. The milk protein isolate in the formula is slow-releasing, making it well-suited to overnight muscle recovery and growth.

What flavours does Critical Mass Professional come in? Multiple flavours are available. Check the product page at Muscle Products Store for current flavour options in stock.

How does Critical Mass Professional compare to other mass gainers? The ingredient profile — particularly the dual creatine matrix, AstraGin™, DigeZyme™, HMB, and LactoSpore™ probiotics — puts it ahead of most standard mass gainers in terms of formulation quality. It is a premium product that justifies its position as one of the UK’s most trusted mass gain supplements.

Is Applied Nutrition a trustworthy brand? Absolutely. Applied Nutrition is one of the most respected sports nutrition brands in the UK, known for transparent labelling, quality ingredients, and consistent product performance across their entire range.

Related Products & Guides

• 👉 Applied Nutrition Critical Mass Original 6kg — Best for Maximum Calories
• 👉 Best Mass Gainer UK 2026 — Top 5 Ranked & Reviewed
• 👉 Best Mass Gainer for Skinny Guys UK 2026
• 👉 Best Creatine UK 2026 — Top 7 Ranked & Reviewed
• 👉 Shop All Mass Gainers at Muscle Products Store

Applied Nutrition Critical Mass Professional is stocked and sold at Muscle Products Store with fast UK delivery. All product information is based on the manufacturer’s specification and real customer feedback.