Protein · head-to-head

Optimum Nutrition Gold Standard vs Applied Nutrition ISO-XP.

Our independent head-to-head review of Optimum Nutrition Gold Standard 100% Whey Protein Powder and Applied Nutrition ISO-XP 1kg, scored on value, protein density, macros and ingredient quality so you don't have to guess which to buy.

WheyWise verdict
Applied Nutrition ISO-XP 1kg wins for most buyers.

90g protein per 100g vs 79g - more protein per scoop

Near-zero carbs and fat for superior macros

Typically cheaper per 100g than Gold Standard

Ingredient quality

Ingredients, line by line.

Every ingredient on each label, classified. Approved means nutritionist-positive sources or actives. Neutral is functional (binders, anti-caking, flavouring). Watch flags additives many buyers want to limit.

ApprovedNeutralWatch
Optimum Nutrition Gold Standard 100% Whey Protein Powder
3 Approved
4 Neutral
2 Watchlist
9 total
Applied Nutrition ISO-XP 1kg
2 Approved
2 Neutral
1 Watchlist
5 total
Optimum ingredients
9 total
  • Whey protein isolate (milk)
  • Whey protein concentrate (milk)
  • Hydrolysed whey protein isolate (milk)
  • Soy lecithin (emulsifier)
  • Curcumin (natural colour)
  • Xanthan gum (thickener)
  • Flavourings
  • SucraloseWatch
  • Acesulfame KWatch
Whey blend (98%) is the constant; flavours / colours vary.
View source panel →
Applied ingredients
5 total
  • Whey protein isolate (milk) (≈97%)
  • Sunflower lecithin (emulsifier, soy-free)
  • Fat-reduced cocoa powder
  • Flavouring
  • SucraloseWatch
Chocolate variant; soy-free formulation across flavours (sunflower lecithin only).