Our readers keep the lights on and my morning glass full of iced black tea. As an Amazon Associate, I earn from qualifying purchases.7 Best Protein Shakes For Weight Gain | Stop Looking So Thin

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Optimum Nutrition has long set the benchmark for quality in sports nutrition, and the Gold Standard Pro Gainer delivers exactly what a hard gainer needs: 650 calories and 60 grams of protein per serving. The vanilla custard flavor is notably rich and creamy — reviewers consistently report it tastes better than most weight gain powders, which is critical when you’re drinking it daily.

The carb blend includes over 80 grams per serving with less than 8 grams of sugar, meaning the calorie surplus comes from real food ingredients rather than cheap fillers. Users mention gaining 5 pounds within a week when pairing it with targeted exercise, making it one of the fastest-acting mass gainers on the market.

One practical note: the serving size yields 14 scoops per container, not the 28 pictured on older packaging. That still translates to two weeks of solid mass-building when used once daily. The mixability is excellent — no clumps or chalky residue, just a smooth shake that goes down easy before bed or post-workout.

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Animal Meal stands out because it uses real whole-food ingredients as the carb source — sweet potato powder, pea starch, tapioca dextrose, and rolled oats — instead of cheap maltodextrin. Each two-scoop serving provides 46 grams of protein from a blend of pea protein isolate, instant egg white, whole egg, and beef protein isolate, making it lactose-free and gentle on digestion.

Reviewers who have tried countless meal replacements note that this one tastes like actual food, with a noticeable oat and egg white character rather than artificial sweetness. It mixes easily in a shaker bottle with no clumping, and the chocolate flavor is described as “not overly sweet” — a relief for anyone who finds standard gainers cloying.

The main caveat is value: a tub provides roughly 20 servings, so daily use runs about per month. But if clean ingredients and digestive comfort matter more than raw calorie count, this is the cleanest option in the lineup. Users report improved energy levels within a week and no bloating.

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For anyone who reacts poorly to whey or dairy, CARNIVOR Mass Gainer is the solution. It uses beef protein isolate — a lactose-free, fat-free, cholesterol-free protein source that digests quickly and is 350% more concentrated in amino acids than steak. Each serving delivers over 700 calories, 50 grams of protein, and 125 grams of carbs with zero fat and zero sugar.

The chocolate peanut butter flavor is a standout — reviewers describe it as tasting like chocolate milk rather than a heavy, chalky gainer. It mixes surprisingly well for a mass gainer; you can fit three scoops in a standard shaker cup without it turning into pudding. Users with fast metabolisms report it helps maintain and add weight without the bloat typical of dairy-based powders.

One concern is the faint beef smell that some users notice, though the chocolate and coffee notes mask it effectively. Using a blender rather than shaking by hand yields the smoothest texture. For those who want a halal-certified, dairy-free mass builder, this is the strongest option in the premium tier.

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Quest’s ready-to-drink shake packs 45 grams of protein per 14-ounce bottle with only 2 grams of sugar and 3 grams of net carbs. That’s an absurdly clean macro profile for the protein content — ideal for anyone tracking every gram. The vanilla flavor is frequently called “the best vanilla protein shake” by reviewers, who note it tastes like a real vanilla milkshake with no artificial aftertaste.

Because it’s a ready-to-drink format, there is zero prep or cleanup. That convenience matters when you’re trying to add a shake between meals without stopping to blend or shake a bottle. Users freeze it slightly to achieve a milkshake consistency, which makes hitting macros feel like a treat rather than a chore.

The slight trade-off is a minor chalky finish that some detect after swallowing, though it’s less pronounced than chocolate versions. This shake is best for adding protein between meals rather than functioning as a full meal replacement, since the calorie count is lower than a mass gainer. Keep it refrigerated for the best taste.

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Slate Milk has reinvented what a protein shake can taste like by using ultra-filtered real milk instead of powdered concentrates. The result is a chocolate shake that tastes exactly like a glass of chocolate milk — smooth, not thick, without any chalky or bitter aftertaste. Each 15-ounce can delivers 42 grams of protein at only 190 calories, making it one of the most efficient protein-to-calorie ratios available.

Because the protein is concentrated through filtration rather than powder, the shake is naturally lactose-free and contains no added sugar, no artificial colors, and no acesulfame potassium. Reviewers who struggle with whey aftertaste or digestive bloat report zero issues with Slate. It works well as a breakfast boost, post-workout recovery, or late-night snack replacement.

The only drawback is the price point — it sits in the premium tier. Additionally, some packaging arrives damaged during shipping, and the salted caramel flavor has been noted to contain undissolved white chunks. Stick with chocolate for the most consistent experience.

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BOOST Very High Calorie is formulated for medical weight maintenance — it’s the go-to for cancer patients, elderly individuals with low appetite, or anyone who needs to consume dense calories in a small volume. Each 8-ounce bottle packs 530 calories, 22 grams of protein, and 26 vitamins and minerals. The variety pack includes vanilla, chocolate, and strawberry to prevent flavor fatigue.

Users consistently highlight how palatable these are compared to other medical nutrition drinks. There’s no chalkiness or artificial aftertaste, and the 8-ounce size makes it manageable even for those who struggle to eat. Caregivers report it helped terminally ill family members regain weight and extend quality time.

That said, this is not a traditional gym mass gainer. The protein-to-calorie ratio is lower (22g protein for 530 calories), so it’s not optimized for muscle building. It’s best used as a calorie-dense snack or mini-meal for general weight maintenance rather than athletic mass gain.

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Premier Protein adds a twist to the weight gain equation by including 7 grams of prebiotic fiber alongside 25 grams of whey protein. The fiber supports gut health and helps you feel fuller longer, which can be useful if you’re trying to manage appetite between meals. The vanilla flavor is award-winning and versatile — it works well in smoothies, oatmeal, coffee, or even used dry as a topping on fruit.

Reviewers consistently praise the taste, calling it the best vanilla protein powder they’ve tried. It blends smoothly with nondairy creamer and peanut butter, and refrigerating it thickens the shake to a satisfying consistency. Lactose-intolerant users report no digestive issues, which is notable for a whey-based powder.

The calorie density is lower than a traditional mass gainer at roughly 150-170 calories per scoop depending on your liquid, so you’ll need multiple servings to build a substantial surplus. This is better suited as a protein supplement with gut health benefits rather than a dedicated mass builder.