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#5 in Protein Powders Third-Party Tested

Optimum Nutrition Gold Standard 100% Casein

by Optimum Nutrition

"Slow-digesting micellar casein for overnight muscle recovery — the gold standard in nighttime protein"

Amazon Rating
4.5/5
Reviews
18,000+
Price Range
$32-40
Servings
28 servings
Informed Choice CertifiedGMP Certified
Our Editorial Rating
8.6
Very Good
FormPowder
SubcategoryCasein Protein
View on Amazon

Overview

Optimum Nutrition Gold Standard Casein provides 24g of slow-digesting micellar casein protein per serving. Unlike whey protein which digests quickly, casein forms a gel in the stomach and releases amino acids gradually over 6-8 hours, making it ideal for overnight muscle protein synthesis. The formula delivers 5g of BCAAs and 5g of glutamine per serving. ON Gold Standard Casein has been the category leader in casein protein for over a decade, trusted by bodybuilders and athletes who want to maximize their recovery window during sleep.

Key Ingredients

IngredientAmount
Micellar Casein24 g
BCAAs5 g
Glutamine & Glutamic Acid5 g

Pros & Cons

What We Like

  • Slow-release protein (6-8 hours)
  • 24g protein per serving
  • Gold Standard quality from ON
  • Thick, pudding-like texture
  • Ideal for overnight recovery

What Could Be Better

  • Thicker and harder to mix than whey
  • Contains milk allergens
  • More expensive per serving than whey
  • Only 28 servings per container

Who Is This For?

Best For

  • Nighttime protein supplementation
  • Bodybuilders in cutting phase
  • Those wanting sustained amino acid release
  • Between-meal protein

Not Ideal For

  • Lactose-intolerant individuals
  • Those wanting fast-absorbing protein
  • Post-workout immediate use

Our Verdict

8.6/10 — Very Good

ON Gold Standard Casein remains the king of nighttime protein. The slow-digesting micellar casein provides a sustained amino acid drip that whey simply can't match. Mix it thick before bed for a protein pudding that feeds your muscles while you sleep.

Alternatives to Consider

No direct alternatives listed for this product yet.