Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg)
by Reflex
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Reflex Nutrition Instant Mass Heavyweight is a high-calorie mass gainer delivering over 1,000 kcal per 300g serving, with 60g of protein sourced from grass-fed whey concentrate, hydrolysed whey, milk protein, and glutamine peptides, plus added creatine and 18 vitamins and minerals. Best for Hard gainers who consistently struggle to hit calorie targets and Busy individuals needing a convenient high-calorie supplement between meals.
According to the AIScored 0–100 scoring system, Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) by Reflex scores 67.0/100, ranking #126 out of 174 products in Whey Protein (2026). Strongest category: Effectiveness (76.0/100). Weakest: Certifications (38.0/100).
Is Reflex Nutrition Instant Mass He... worth buying?
“At 67/100, Reflex Instant Mass Heavyweight packs over 1,000 calories and 60g of grass-fed whey protein per serving—the calorie density works for serious hard gainers trying to build weight. It mixes cleaner than rival mass gainers, so you won't be choking down gritty shakes every time you drink it.”
What Do Reviewers Say About Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg)?
Sample excerpts from currently available source material used in this product analysis.
"Not a food person in the morning so this works great. Good taste and mixes well. Not gritty, good value and feel much better after a few weeks. Can't comment on gym use as I don't go."
"This could be life changing! Been trying to bulk for a while and always become inconsistent with it, this just keeps me on track so nicely. I recommend splitting the “serving into 2” to reduce the density. So have 350ml water/milk and then..."
"Great protein shake that helps top up your calories if you’re someone that struggles to keep your calories full, people keep buying chocolate and complaining about the taste however the vanilla is great! No powdery taste at all and i have i..."
"good mix but i ordered 2 tubs and get one and days later get another why cant they just send the 2 at once hmm"
"Husband loves this! He has purchased this 3 times now, uses it in between meals and on days where he’s out for work and doesn’t have time to grab something to eat. It’s been great for helping him put on weight. Really lovely flavour and mix..."
How does Reflex Nutrition Instant Mass Heavywe... score?
Detailed score breakdown and key findings from our analysis of 10 reviews across 1 source.
Pros
- +Effective calorie vehicle — 1,000+ kcal per serving reliably helps hard gainers reach daily surplus
- +Multi-source protein blend (grass-fed whey concentrate, hydrolysed whey, milk protein) with 60g per serving
- +Mixes cleanly with minimal clumping, better than many competitors in the mass gainer segment
- +Creatine, EAAs, and 18 vitamins and minerals included — a genuinely comprehensive all-in-one formulation
- +Strong value for money relative to similar high-calorie gainers on the UK market
Cons
- -Full 300g serving regularly causes bloating, wind, and nausea — nearly all experienced users recommend starting at half dose
- -High sugar content flagged by multiple reviewers — unsuitable for those managing blood sugar or seeking a lean bulk
- -Not third-party tested, meaning purity and label accuracy are not independently verified
- -Chocolate flavour receives inconsistent feedback; some find it acceptable, others mediocre
Best For
Watch Out
- !Begin with a half serving (150g) for the first week to assess digestive tolerance
- !High sugar content — not appropriate for lean bulk goals or anyone monitoring glycaemic load
- !No third-party certification — purity and heavy metal content unverified
- !Multiple allergens present: milk, soy, wheat, and possible egg cross-contamination
What is Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg)?
Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) is a whey protein product by Reflex in powder form, scoring 67.0/100 on AIScored.
- • Engineered for Gains: This seamless protein shake mix is specifically formulated to accelerate muscle and weight gains and improve post-workout recovery, enhancing overall workout performance for the dedicated, hard gainer and serious athlete alike Excellent Nutrition Profile: Packed with quality ingredients, each protein shake serving delivers over 1000 kcals, 200g of complex carbohydrates, 60g of muscle gain protein, critical EAAs, creatine, 18 vitamins and minerals (B12, B6, C, Iron, Zinc) Outstanding Taste Sensation: Our Chocolate Perfection mass gainer flavour isn't just a treat for your taste buds - it's a deliciously creamy escape into indulgence with every sip, all while you are fueling your body for mass gain and muscle recovery Optimal Timing for Maximum Impact: Consume Instant Mass Heavyweight high protein shake between meals for a positive nitrogen balance, 20-30 minutes post workout for best results or 45-60 minutes before sleep to aid overnight muscle maintenance Trusted Quality Assurance: Reflex Nutrition's promise to quality means whey protein powder from grass-fed cows - Protein Sources are Glutamine Peptides, Whey Protein Concentrate, Milk Protein, Hydrolysed Whey Protein.
Is Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) Independently Tested?
No Third-Party Testing Visible
We could not find evidence of independent third-party testing for this product. This doesn't mean it's unsafe, but independent verification provides additional assurance.
How We Score Supplements
Our methodology analyses review data, ingredient science, and product information, then scores each product on a 0-100 scale across evidence-based categories:
Effectiveness
How well the product delivers its claimed benefits, based on reviews and ingredient evidence.
Ingredient Quality
Bioavailable forms, clinically effective dosages, clean label, minimal fillers.
Value for Money
Price relative to ingredient quality, dosage count, and effectiveness.
Side Effects Profile
Higher score = fewer side effects. 100 means virtually no adverse reactions reported.
Certifications & Testing
Third-party lab testing, GMP certification, and independent quality verification.
Overall Score
Weighted combination of all factors. Our bottom-line recommendation.
Price History (90 days)
Quick Facts
- Form
- Powder
- Serving
- 300 g
- Vegan
- No
Frequently Asked Questions
Is Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) worth buying in 2026? ▼
What is the best price for Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) in the UK? ▼
What are the pros and cons of Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg)? ▼
Is Reflex Nutrition Instant Mass Heavyweight - Mass Gainer - Over 1000 Kcal per Serving, 60g Protein, Creatine - High Calorie Post Workout or Before Bed Protein Shake (Chocolate Perfection, 2 kg) third-party tested? ▼
What the Data Says About Whey Protein
What makes a clean whey protein? Ingredient quality scores across 169 UK products
Fewer ingredients = cleaner protein. We scored 169 whey proteins on ingredient quality (IQ) and the gap between top and bottom is massive: 65 points, from 95/100 down to 30/100.
The top 7 products by IQ all share one trait — minimal ingredient lists:
- PINK SUN Organic Whey Concentrate — IQ 95, overall 85
- Isopure Unflavoured Whey Isolate — IQ 91, overall 76
- LEGION Whey+ Isolate — IQ 91, overall 80
- PINK SUN Whey Isolate Unflavoured — IQ 91, overall 81
- Purition 100% Whey Isolate 93% Protein — IQ 91, overall 80
- Dymatize ISO100 — IQ 90, overall 84
- Naked Whey (1 ingredient) — IQ 90, overall 74
The bottom tells the opposite story. Products like BodyFuel Clear Protein (IQ 30), Amfit Nutrition (IQ 38), and Protein Dynamix 3XP (IQ 38) use multi-source protein blends padded with artificial sweeteners, thickeners, and colourings.
The average across all 169 products is 70.7/100. If your whey protein has more than 5-6 ingredients, check what's filling up that list. A clean whey needs protein, maybe a natural flavour, and not much else.
Can cheap whey protein cause bloating? What to check on the label
Cheap whey often causes bloating because of what's added to the protein, not the protein itself. We scored 169 whey proteins and the worst-scoring products share the same filler-heavy ingredient profiles.
Three categories of additives show up repeatedly in low-IQ products (scored 30-42):
- Thickeners — xanthan gum, carrageenan, cellulose gum. These bulk up texture but can cause gas and bloating in sensitive stomachs.
- Artificial sweeteners — sucralose, acesulfame-K, aspartame. Linked to gut microbiome disruption in some studies. Budget brands use these heavily.
- Anti-caking agents and emulsifiers — added to improve mixability, but another source of digestive irritation.
Products like BodyFuel Clear Protein (IQ 30), Amfit Nutrition (IQ 38), and SCI-MX Ultra Muscle (IQ 42) stack several of these additives together.
Compare that to the top scorers: PINK SUN Organic Whey (IQ 95) and Naked Whey (IQ 90) use 1-3 ingredients total. No thickeners, no artificial sweeteners, no fillers. Users report far less digestive trouble with these minimal formulas.
Label check shortcut: flip the tub over. If the ingredient list has more than 6 items, or you spot carrageenan, sucralose, or acesulfame-K, that's your likely bloating culprit. A whey isolate with a short list costs a bit more but your gut will thank you.
Disclaimer: AIScored provides research-backed summaries based on publicly available reviews and product information. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Affiliate links may earn us a commission at no extra cost to you.
What Are Other Top Whey Protein?
Other top-rated whey protein you might want to compare.
100% Whey Protein Isolate, 93% Protein, Triple-Filtered, Unsweetened, Unflavoured, Soy Free, Low Fat, 23g Protein per Serving, 20 Servings - 500g
Purition
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Millidose
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Protein Dynamix
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