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Best Protein Powder

Optimum Nutrition

Gold Standard Pro Gainer

Optimum Nutrition Gold Standard Pro Gainer is a mass gainer protein powder with 60 g of protein per 165g (About 1 Scoop). It scores 39/100 on the TBPP Quality Score. We found no third-party testing certification.

No third-party testing found7 g sugar
Our score
39/100
Methodology v1.0
Protein
60g
165g (About 1 Scoop)
Sugar
7g
Per serving
Protein by weight
36%
Per serving
$7.86
$3.27 per 25 g protein

Nutrition per serving

Double Chocolate flavor, from the label.

Nutrition per serving
Serving size165g (About 1 Scoop)
Protein60 g
Calories650
Carbohydrates81 g
Sugar7 g
Fat9 g
Sodium340 mg
Protein by weight36%
LeucineNot verified
BCAAsNot verified

How it scored

39 of 100 points. How we score

CriterionPointsWhy
Protein density6 / 3036% of each scoop is protein
Third-party testing0 / 25No verified independent testing program
Label transparency20 / 20Fully disclosed formula, no amino spiking
Sugar2 / 107 g sugar per serving
Ingredient simplicity6 / 10Mix of natural and artificial flavors or sweeteners
Verified label data5 / 57 of 7 label values verified

Formula and label

Formula and label
TypeMass Gainer
Protein sourcesWhey Protein Isolate, Whey Protein Concentrate, Calcium Caseinate, Hydrolyzed Whey Protein
Third-party testingNone found
SweetenersSucralose, Acesulfame Potassium
Proprietary blendNo
Added free amino acidsNo
DietaryNone listed
AllergensMilk, Soy
Made byOptimum Nutrition (Glanbia) · USA
Sold atOptimum Nutrition (official store)

Price

$109.99–$166.49 for 5.09 lb. About $7.86 per serving, or $3.27 per 25 g of protein.

Sizes: 5.09 lb, 10.19 lb

Flavors (2)

  • Double Chocolate
  • Vanilla Custard

Sources

Nutrition and ingredients from the brand's US Double Chocolate 5.09 lb label image (165 g serving, 14 servings; 4 g added sugars, 5 g fiber); first ingredient is Maltodextrin, followed by a whey/casein protein blend, MCTs and a vitamin/mineral blend. Brand page states 81-82 g carbs depending on flavor. Label shows a generic 'Banned Substance Tested' mark only, so no certification listed; the European 'Gold Standard Gainer' was withdrawn from Informed Choice in 2024. Prices are brand-store list prices on 2026-10-13. Retailer carriage beyond the brand store not verified in this pass.

Good to know

Last checked 2026-10-13. Labels change, so check the package before buying if you have allergies. If you are pregnant, nursing or buying for a child, ask your doctor before adding a supplement.

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Protein
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Sugar
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Our score
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Informed Choice
Protein
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Sugar
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Our score
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No third-party testing found
Protein
25g
Sugar
0g
Our score
71/100
$2.35 / servingChecked 2026-10-13