Optimum Nutrition Gold Standard 100% Micellar Casein Protein Powder
Optimum Nutrition Gold Standard 100% Casein is a premium mainstream casein powder for users who want slow-digesting protein from a highly recognized sports nutrition brand.
Editorial review
Product-specific buying guidance
Overview
Optimum Nutrition Gold Standard 100% Casein is a premium mainstream casein powder for users who want slow-digesting protein from a highly recognized sports nutrition brand.
What makes it different
Its key strength is that 100% of the protein comes from micellar casein, with 24g protein and 9g EAAs per serving according to official brand information.
Best use case
Best for nighttime protein, between-meal protein, or users who prefer casein over fast-digesting whey.
Limitations
It is dairy-based, slower digesting, and flavor-specific labels may include artificial sweeteners. It is not the right fit for vegan users.
Comparison note
Compared with Nutricost Casein, ON has stronger brand recognition and premium positioning. Compared with whey protein, it is better suited for slower-release use cases.
Final verdict
A strong premium casein pick for buyers who want slow-digesting micellar casein from a trusted sports nutrition brand.
Score breakdown
Internal editorial score
This is an internal score out of 10, not an marketplace rating.
- Brand trust
- 9.4/10
- Product relevance
- 8.8/10
- Ingredient/spec clarity
- 8.6/10
- Buyer intent fit
- 8.8/10
- Value expectation
- 8.1/10
- Availability confidence
- 8.8/10
Pros
- 24g protein per serving
- 100% of protein from micellar casein
- Strong brand recognition in sports nutrition
Cons
- Not vegan or dairy-free
- Slower digesting than whey, which may not suit every use case
- Flavor-specific sweeteners and additives require label verification
Key details
Product details
- Brand
- Optimum Nutrition
- Product type
- Micellar Casein Protein
- Category
- Protein & Muscle Building
- Primary use case
- Users who want slow-digesting micellar casein
- Suitable goals
- muscle gain, recovery
- Last updated
- 2026-05-08
Ingredients & Formula
Formula notes
ON Gold Standard 100% Casein is positioned as a slow-digesting micellar casein protein for nighttime or between-meal use.
- Verification status
- partial
- Main ingredients
- Micellar casein, Flavor-specific ingredients vary by flavor
- Active ingredients
- Micellar casein
- Protein source
- Dairy-based micellar casein
- Sweeteners
- Flavor-specific; verified Chocolate Supreme retailer label lists sucralose and acesulfame potassium
- Allergen info
- Contains milk/casein. Flavor-specific labels may include soy lecithin or other allergen warnings.
- Serving info
- Serving details vary by flavor/size; verify exact label.
Nutrition highlights
- 24g protein per serving
- 100% of protein from micellar casein
- 9g EAAs per serving
- Excellent source of magnesium and zinc according to official page
- Slow-digesting protein positioning compared with whey
- Form
- Powder
- Flavor
- Multiple flavors
- Package size
- Varies by listing
- Diet tags
- Dairy-based, Not vegan
- Certifications
- Informed Choice testing positioning on some listings
- Protein per serving
- 24g
- Calories per serving
- Flavor-specific
- Carb info
- Flavor-specific
Best for / avoid if
Best for
- Users who want slow-digesting micellar casein
- People looking for nighttime or between-meal protein
- Buyers who prefer a major sports nutrition brand
Avoid if
- You need vegan or dairy-free protein
- You want fast-digesting whey protein
- You avoid artificial sweeteners
Medical disclaimer
SupplementCheckLab provides product research and buying guides for informational purposes only. We do not provide medical advice. Always consult a qualified healthcare professional before starting any supplement, especially if you are pregnant, nursing, taking medication, or have a medical condition.
FAQ
Quick buying questions
What type of protein is ON Gold Standard Casein?+
It is a micellar casein protein powder.
How much protein does it provide?+
Optimum Nutrition lists 24g protein per serving.
When is casein usually used?+
Casein is commonly chosen for between-meal or nighttime-style protein because it digests more slowly than whey.
Is it vegan?+
No. Micellar casein is milk-derived.
How does it compare with Nutricost Casein?+
ON has stronger premium brand recognition, while Nutricost may appeal more to value-focused buyers.