Mass gainers comparison
Optimum Nutrition Serious Mass vs Dymatize Super Mass Gainer
Dymatize Super Mass Gainer scores higher on our standard, 54/100 to 39/100. It earns more points for third-party testing (Informed Choice vs none found).
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.
Optimum Nutrition
Serious Mass
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 | ON Serious Mass | Dymatize Super Mass Gainer |
|---|---|---|
| Our score | 39/100 | 54/100 (better) |
| Protein density | 6 / 3015% of each scoop is protein | 6 / 3016% of each scoop is protein |
| Third-party testing | 0 / 25No verified independent testing program | 15 / 25 (better)Independently tested for contaminants or label accuracy |
| Label transparency | 20 / 20Fully disclosed formula, no amino spiking | 20 / 20Fully disclosed formula, no amino spiking |
| Sugar | 2 / 1029 g sugar per serving | 2 / 1021 g sugar per serving |
| Ingredient simplicity | 6 / 10Mix of natural and artificial flavors or sweeteners | 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 | Mass Gainer | Mass Gainer |
| Protein per serving | 50 g | 52 g |
| Serving size | 340 g (About 2 Scoops) | 2 1/2 cups (335 g) with 24 oz water |
| Protein by weight | 15% | 16% (better) |
| Sugar | 29 g | 21 g (better) |
| Calories | 1260 | 1280 |
| Cost per 25 g protein | Not verified | Not verified |
| Price per serving | Not verified | Not verified |
| Third-party certifications | None found | Informed Choice |
| Sweeteners | Acesulfame Potassium, Sucralose | Fructose, Acesulfame Potassium, Sucralose |
| Allergens | Milk, Soy | 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 ON Serious Mass if…
On the label facts we track, ON Serious Mass has no clear edge over Dymatize Super Mass Gainer. Taste, how it mixes and the price where you shop may still decide it.
Choose Dymatize Super Mass Gainer if…
- You want independent testing for contaminants or label accuracy (Informed Choice); we found no third-party testing for ON Serious Mass.
- You want more protein per serving (52 g vs 50 g).
- You want less sugar (21 g vs 29 g per serving).
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.