Optimum Nutrition Serious Mass Chocolate
Summary
Optimum Nutrition Serious Mass Chocolate scores 27/100. 1,260-calorie, 50 g protein mass gainer built on whey protein concentrate plus 250 g of carbohydrates per serving — almost entirely maltodextrin and oat flour — with creatine, glutamine, BCAAs, and a 25-vitamin/mineral blend. But Informed Choice certification covers banned substances, NOT heavy metals, and independent third-party lab testing (Consumer Reports, January 2024) detected 8.43 mcg arsenic per serving — the HIGHEST single-metal value in the entire 23-product 2024 protein survey. Likely source: the oat flour and grain-derived carb base. Owned by Glanbia Performance Nutrition.
At a glance
Contaminants 4
Source: Consumer Reports January 2024
Lead 0.61 mcg per serving Moderate
A moderate level of lead — elevated enough to be a real sourcing concern; cleaner-tested options exist.
Independent third-party testing.
Cadmium not detected Not detected
Not detected — below the laboratory's detection limit. This is the strictest possible result: no measurable amount was found.
Consumer Reports January 2024 reported cadmium below the lab's threshold of detection — no cadmium measurable in this product.
Arsenic 8.43 mcg per serving High
Detected at a high level — at or above health-based exposure limits. Regular exposure at this level is a genuine health concern. Arsenic is an IARC Group 1 carcinogen with no safe exposure level. Likely source: oat / grain / rice ingredients in the carbohydrate base.
Consumer Reports January 2024 detected 8.43 mcg arsenic per serving.
Mercury not detected Not detected
Not detected — below the laboratory's detection limit. This is the strictest possible result: no measurable amount was found.
Consumer Reports January 2024 reported mercury below the lab's threshold of detection — no mercury measurable in this product.
Key ingredients 13
Whey Protein ConcentrateVery Good
Complete dairy protein with high bioavailability and a rich amino acid profile. Retains beneficial bioactive compounds; primary protein source delivering 50 g per serving.
See more about Whey Protein Concentrate →MaltodextrinVery Bad
High-glycemic-index filler (GI 85-105) that spikes blood sugar faster than table sugar. Used as a cheap bulking agent providing the bulk of the calorie load in this mass gainer with zero meaningful nutritional benefit. Linked to gut microbiome disruption.
See more about Maltodextrin →Oat FlourNeutral
Whole-grain carbohydrate source providing fiber and a slower-release carb component than pure maltodextrin. Oats are also a known arsenic accumulator from soil — the suspected primary source of the 8.43 mcg arsenic detected here.
See more about Oat Flour →Cocoa (Processed with Alkali)Neutral
Dutch-processed cocoa has reduced flavanol and antioxidant content compared to natural cocoa.
See more about Cocoa (Processed with Alkali) →Creatine MonohydrateVery Good
Most-researched ergogenic supplement on the market. Robustly supports strength, power output, and lean mass gains. A genuinely beneficial inclusion in a mass gainer.
See more about Creatine Monohydrate →BCAAs (L-Leucine, L-Valine, L-Isoleucine)Good
Free-form branched-chain amino acids supporting muscle protein synthesis and recovery.
See more about BCAAs (L-Leucine, L-Valine, L-Isoleucine) →L-GlutamineGood
Conditionally essential amino acid supporting recovery and gut health.
See more about L-Glutamine →InositolNeutral
Vitamin-like compound used in trace amounts; minor metabolic role.
See more about Inositol →PABANeutral
Para-aminobenzoic acid; B-vitamin complex member with minimal evidence of supplementation benefit.
See more about PABA →Vitamin and Mineral Blend (25 nutrients)Neutral
Synthetic micronutrient fortification covering vitamins A, C, D, E, B-complex, calcium, iron, zinc, magnesium and more.
See more about Vitamin and Mineral Blend (25 nutrients) →Soy LecithinBad
Typically derived from GMO soybeans using hexane extraction. Adds an emulsifier without nutritional benefit.
See more about Soy Lecithin →Natural and Artificial FlavorsBad
Synthetic chemical compounds with zero transparency on composition and no nutritional value.
See more about Natural and Artificial Flavors →SucraloseBad
Chlorinated artificial sweetener linked to disruption of gut microbiome, potential insulin response issues, and generation of harmful chlorinated compounds during metabolism.
See more about Sucralose →Processing
Ultra-Processed Foods
Get the full breakdown in the Scout app
Scan any product to see lab results, healthy alternatives, and your personalized analysis.
Download on theApp Store