Mass Gainers
High-calorie mass gainers combine protein and carbohydrates to help hard gainers and athletes build muscle mass. Look for products with 40–60g of quality protein, complex carb sources, and a calorie count that fits your daily surplus goal — whether you need a modest 600-calorie boost or an extreme 1,250+ calorie shake.
Reviews & Guides
Best Mass Gainers 2026 for Hard Gainers
The best mass gainer protein powders for building size. High calorie, high protein options for ectomorphs and hard gainers.
Read review →Best Mass Gainer for Skinny Guys 2026: Bulk Up Fast
Hard gainer? Struggling to add size? We review the best mass gainer supplements for skinny guys who want to build muscle and bulk up fast.
Read review →Mass Gainer vs Protein Powder: Which Is Right for You?
Not sure whether to buy a mass gainer or regular protein powder? We break down the key differences in calories, carbs, and use cases so you can choose the right supplement for your goals.
Read review →How to Use Mass Gainers Without Getting Fat
Mass gainers can help you build muscle — or they can add unwanted body fat if you use them wrong. Learn how to time, dose, and pair mass gainers with training for lean gains.
Read review →Best Mass Gainer for Beginners: Start Here
New to mass gainers? This beginner's guide explains what to look for, which products to avoid, and which mass gainers are the safest starting point for someone new to bulking.
Read review →Clean vs Dirty Mass Gainers: What the Labels Don't Tell You
The supplement industry uses "clean" and "dirty" loosely. We break down what these terms actually mean for mass gainers, what ingredients to watch for, and which products deliver on their clean-label claims.
Read review →Mass Gainer Nutrition Facts: What to Look For
Before you buy a mass gainer, you need to understand the nutrition label. This guide explains calories, protein types, carb sources, sugar content, and serving size tricks that affect your real-world results.
Read review →Best Mass Gainer for Women: Building Lean Muscle
Women can benefit from mass gainers too — but the strategy is different. This guide covers which mass gainers work best for women building lean muscle, and how to use them without unwanted fat gain.
Read review →Top Rated Products
Optimum Nutrition Serious Mass Weight Gainer Protein Powder, Chocolate, 12 lb
Optimum Nutrition
NAKED Mass Natural Weight Gainer Protein Powder, Unflavored, 8 lb
Naked Nutrition
BSN TRUE-MASS Weight Gainer Protein Powder, Chocolate Milkshake, 5.82 lb
BSN
Optimum Nutrition Gold Standard Pro Gainer, Vanilla Custard, 5.09 lb
Optimum Nutrition
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Mass Gainer Buyer's Guide (2026)
What Is a Mass Gainer?
A mass gainer is a high-calorie protein supplement that delivers 600–2,000+ calories per serving by combining protein (typically 40–63g) with a large amount of carbohydrates. They're designed specifically for people who struggle to eat enough calories through whole food to support muscle growth — commonly called "hard gainers" or ectomorphs.
Unlike standard whey protein (which delivers 100–150 calories and 20–30g of protein), mass gainers are purpose-built for caloric surplus. If your goal is adding bodyweight and building muscle and you consistently fall short of your daily calorie target, a mass gainer can fill that gap efficiently.
Mass Gainer vs. Whey Protein: Which Do You Need?
| Factor | Mass Gainer | Whey Protein |
|---|---|---|
| Calories per serving | 600–2,000+ | 100–150 |
| Protein per serving | 40–63g | 20–30g |
| Carbohydrates | 100–250g+ | 3–10g |
| Best for | Hard gainers, athletes needing calorie surplus | General protein supplementation |
| Use if you... | Can't eat enough calories to gain weight | Need more protein but not more calories |
How to Choose a Mass Gainer: 5 Key Factors
1. Calorie Count
Match calorie density to your daily surplus goal. If you need 500 extra calories/day, a 1,250-calorie serving is overkill and may cause unwanted fat gain. Calculate your TDEE first, then choose a mass gainer that bridges the gap — not blows past it.
2. Protein Source Quality
Look for whey concentrate, whey isolate, or a multi-protein blend (whey + casein + egg) as primary protein sources. Avoid products where the protein matrix is padded with low-quality sources like collagen or soy at the top of the ingredient list.
3. Carbohydrate Sources
"Clean" mass gainers use complex carb sources like oat flour, sweet potato powder, or maltodextrin-free blends. "Dirty" gainers rely heavily on maltodextrin and sugar — fine for extreme hard gainers but less ideal for body composition. Check the ingredient list, not just the marketing.
4. Digestibility
Mass gainer servings are large. Products with digestive enzymes (amylase, protease, lipase) significantly reduce bloating and GI distress. If you're lactose intolerant, look for lactase inclusion or choose a mass gainer using whey isolate rather than concentrate.
5. Third-Party Testing
Look for NSF Certified for Sport, Informed Sport, or Informed Choice certification. Mass gainers are some of the most adulterated supplements on the market — third-party testing verifies what's on the label is actually in the tub.
When to Take a Mass Gainer
The most effective time to take a mass gainer is post-workout — within 1–2 hours after resistance training when muscle protein synthesis is elevated and glycogen stores are depleted. The carbohydrates help replenish glycogen while the protein drives muscle repair.
If post-workout timing doesn't align with your schedule, mass gainers can also serve as a calorie-dense meal between whole food meals. Avoid taking them right before bed if body composition is a concern — the excess calories have limited immediate use during sleep.
Mass Gainer Red Flags to Avoid
- Sugar as a primary carb source — cheap filler; causes insulin spikes and fat storage rather than muscle
- Proprietary blends without weights — you can't verify effective doses of key ingredients
- Protein spiking — cheaper amino acids (taurine, glycine) can inflate protein numbers without contributing to muscle protein synthesis
- No third-party testing — unverified products have been found to contain heavy metals and undisclosed additives
- Calorie counts based on 4-scoop servings — some products use unrealistically large servings to inflate per-serving numbers; compare per-calorie cost instead