Casein comparison
Naked Nutrition Naked Casein Micellar Casein Protein Powder vs Optimum Nutrition Gold Standard 100% Casein
Naked Casein scores higher on our standard, 90/100 to 63/100. It earns more points for third-party testing (NSF Contents Certified vs none found), protein density (87% vs 71% protein by weight) and ingredient simplicity (unflavored vs mixed natural and artificial). We could not verify a current price for ON Gold Standard Casein, so we can't compare cost.
Both are scored out of 100 against our published standard: protein density, third-party testing, label transparency, sugar, ingredient simplicity and verified label data. Every number below is from the manufacturer's label; last checked 2026-10-13.
Naked Nutrition
Naked Casein Micellar Casein Protein Powder
Optimum Nutrition
Gold Standard 100% Casein
Side by side
Per serving, from each label. Bold marks the better score, protein density, sugar and cost where the two differ. How we score
| Compared | Naked Casein | ON Gold Standard Casein |
|---|---|---|
| Our score | 90/100 (better) | 63/100 |
| Protein density | 30 / 30 (better)87% of each scoop is protein | 22 / 3071% of each scoop is protein |
| Third-party testing | 15 / 25 (better)Independently tested for contaminants or label accuracy | 0 / 25No verified independent testing program |
| Label transparency | 20 / 20Fully disclosed formula, no amino spiking | 20 / 20Fully disclosed formula, no amino spiking |
| Sugar | 10 / 100 g sugar per serving | 10 / 101 g sugar per serving |
| Ingredient simplicity | 10 / 10 (better)Unflavored | 6 / 10Mix of natural and artificial flavors or sweeteners |
| Verified label data | 5 / 57 of 7 label values verified | 5 / 57 of 7 label values verified |
| Type | Casein | Casein |
| Protein per serving | 26 g | 24 g |
| Serving size | 30 g (about 2 scoops) | 34g (About 1 Scoop) |
| Protein by weight | 87% (better) | 71% |
| Sugar | 0 g (better) | 1 g |
| Calories | 110 | 120 |
| Cost per 25 g protein | $1.39 | Not verified |
| Price per serving | $1.45 | Not verified |
| Third-party certifications | NSF Contents Certified | None found |
| Sweeteners | None listed | Acesulfame Potassium, Sucralose |
| Allergens | Milk | Milk, Soy |
| Proprietary blend | No | No |
| Added free amino acids (amino spiking) | No | No |
| Last checked | 2026-10-13 | 2026-10-13 |
Which to choose
Only the differences in our records. A value we couldn't verify never counts as a difference.
Choose Naked Casein if…
- You want independent testing for contaminants or label accuracy (NSF Contents Certified); we found no third-party testing for ON Gold Standard Casein.
- You want more protein per serving (26 g vs 24 g).
- You want more of each scoop to be protein (87% vs 71% by weight).
- You want less sugar (0 g vs 1 g per serving).
- You want no sweeteners (ON Gold Standard Casein uses acesulfame potassium and sucralose).
- You avoid soy: ON Gold Standard Casein's label lists it as an allergen and Naked Casein's does not.
- You want a powder the brand labels gluten-free and non-gmo (our record for ON Gold Standard Casein has no such label).
Choose ON Gold Standard Casein if…
On the label facts we track, ON Gold Standard Casein has no clear edge over Naked Casein. Taste, how it mixes and the price where you shop may still decide it.
The two powders
Good to know
Labels and prices change, so check the package before buying, especially if you have allergies. If you are pregnant, nursing, buying for a child or managing a health condition, ask your doctor before adding a supplement.