Two of the most reached-for tubs at GNC, Walmart and Bodybuilding.com, owned by the same Glanbia parent yet positioned for completely different drinkers. COR-Performance Whey vs Syntha-6: macros, flavor, value and which one actually belongs in your cabinet.
Cellucor launched in 2002 in Bridgeport, Texas. The brand built its name on the C4 pre-workout line (the best-selling pre-workout in the United States for the last decade) and expanded into whey, isolate, and creatine. COR-Performance is the protein flagship: 25 to 30 g of protein per scoop, bold flavor system, broad retail distribution. The brand sits in the upper-middle of the price tier, generally undercut by Body Fortress and Six Star on pure dollars-per-gram but trusted for clinical doses and tested formulas. Cellucor is owned by Glanbia Performance Nutrition.
BSN (Bio-Engineered Supplements and Nutrition) launched in 2001 in Boca Raton, Florida and built its empire on a single product: Syntha-6. That formula, released in 2008, used a six-protein blend (whey isolate, whey concentrate, casein, milk protein, egg, plus glutamine peptides) designed for an indulgent flavor experience rather than maximum protein density. The product became one of the best-selling proteins of the 2010s thanks to the Cold Stone Creamery flavor collabs. BSN also makes True-Mass for bulking and Syntha-6 Edge for cutting. Like Cellucor, BSN is now owned by Glanbia.
| Metric | Cellucor COR-Performance Whey (4 lb) | BSN Syntha-6 (5 lb) |
|---|---|---|
| Tub size | 1,810 g / 4 lb | 2,270 g / 5 lb |
| Servings per tub | 56 | 47 |
| Protein per serving | 25 g | 22 g |
| Serving size | 32 g | 47 g |
| Total protein in tub | 1,400 g | 1,034 g |
| Carbs per serving | 5 g | 14 g |
| Sugar per serving | 2 g | 3 g |
| Lowest tracked price | $39.99 (Walmart) | $49.99 (Walmart) |
| Cost per gram of protein | $0.029 | $0.048 |
| Format | Whey blend (concentrate + isolate) | Six-protein blend (whey + casein + egg + milk) |
| Best flavor | Whipped Vanilla, Peanut Butter Marshmallow | Cold Stone Mint Mint Chocolate, Strawberry Milkshake |
On pure protein per dollar, Cellucor wins by a meaningful margin: $0.029 per gram for COR-Performance Whey versus $0.048 for Syntha-6. That gap exists because Syntha-6 is engineered around mouthfeel, not macros. The added carbs, fats, casein and milk protein concentrate create a thicker, more dessert-like shake at the cost of efficiency. If you treat your protein as a macro tool, Cellucor is the cleaner buy.
For meal-replacement positioning, the per-gram math flips. A 47 g serving of Syntha-6 delivers 22 g protein plus 14 g carbs plus 6 g fat, which is roughly 200 calories of complete macros. A 32 g serving of COR-Performance is 130 calories. If you are using protein as a snack, Syntha-6 covers more nutritional ground per scoop.
BSN Syntha-6 is one of the genuinely best-tasting proteins on the market. The Cold Stone Creamery limited editions (Mint Mint Chocolate Chocolate Chip, Birthday Cake Remix, Strawberry Banana Smoothie) routinely win flavor blind-tests against Optimum Nutrition and Quest. The standard lineup (Chocolate Milkshake, Vanilla Ice Cream, Peanut Butter Cookie) is also reliably good. Syntha-6 mixes thick, foams a bit, and behaves more like a dessert than a recovery drink.
Cellucor COR-Performance is competent but not as memorable. Whipped Vanilla, Peanut Butter Marshmallow and Cinnamon Swirl are the strongest picks; Chocolate is solid but slightly thin compared with Syntha-6. COR-Performance mixes cleaner in water and produces less foam, which works better for between-meal sipping.
If protein per dollar is your priority and you mix shakes in water at the gym, buy Cellucor COR-Performance Whey 4 lb. You pay $39.99 at Walmart and get 1,400 g of total protein. Flavor is good enough to drink daily for months without burnout.
If you want your shake to taste like a Cold Stone milkshake, treat your protein as a snack, or want a bedtime casein-heavy formula, buy BSN Syntha-6 5 lb. You will pay a 50 percent per-gram premium but you get the best-tasting tub at GNC, period.
If you cannot decide: split the buy. 2 lb of Cellucor COR-Performance ($24.99) for daily shakes plus 2.91 lb of Syntha-6 Cold Stone Mint ($31.99) for the occasional dessert shake. Combined cost about $57 and you cover both use cases.
True Mass is a mass gainer, Syntha-6 is a protein blend. The True Mass 1200 6 lb tub at $59.99 packs 50 g of protein plus 215 g of carbs and 1,200 calories per shake. It is built for skinny lifters trying to bulk fast. Syntha-6 has roughly 200 calories per shake and is positioned as a regular protein supplement. They sit in completely different categories.
Cellucor's casein line has been discontinued in most retailers. Their current focus is C4 pre-workout, whey, and isolate. If you want a slow-digesting bedtime casein, the closest in-house Glanbia equivalent is Optimum Nutrition Gold Standard 100% Casein (24 g protein per scoop, $49.99 for 4 lb at Walmart).
No. Both products contain naturally-occurring lactose because they use whey concentrate and milk protein concentrate. If you are lactose sensitive, step up to Cellucor COR-Performance Isolate (filtered to remove most lactose, $54.99 for 5 lb) or look at Dymatize ISO100 for a true sub-1 g lactose product.
BSN Syntha-6 has been the bigger seller at GNC for over a decade, partly due to the Cold Stone flavor exclusives. Cellucor moves more total units when you include the C4 pre-workout line, but for protein specifically, Syntha-6 routinely tops GNC's monthly protein chart. Both brands rotate through GNC's gold-card BOGO 50% off promotion roughly every six weeks.
BSN Syntha-6 launched in 2008. The formula has had minor flavor refinements but the core six-protein matrix is unchanged. Cellucor COR-Performance Whey launched in 2014, with COR-Performance Isolate following in 2017. Both products have outlived dozens of competitors and continue to sell in the millions of units per year worldwide.