⚠ Regulatory History FDA Warning Letter (2011): "Muscle Milk" name flagged as misleading — product contains no milk. FTC (2010): advertising claims referred for review. Consumer Reports (2010): lead, cadmium, and arsenic levels at or above USP limits in tested powder products.
Traced/ Supplements · Protein Shake

Muscle Milk

RTD Protein Shake & Powder — PepsiCo / Gatorade

Traced Assessment

Muscle Milk invented the mainstream protein RTD category in the early 2000s and paid for that invention with years of regulatory friction. The name is misleading — the FDA formally said so in a 2011 warning letter. The protein blend uses calcium and sodium caseinate alongside milk protein concentrate and whey — cheaper, slower-digesting sources than the isolates and egg whites that performance-oriented competitors use. In 2010, Consumer Reports found lead, cadmium, arsenic, and mercury in Muscle Milk powder at levels at or above United States Pharmacopeia limits. The FTC and National Advertising Division both reviewed advertising claims in 2009–2010. The brand was acquired by Hormel Foods in 2014 for $450 million, then sold to PepsiCo in 2019 for $465 million, where it now operates as a Gatorade subsidiary. PepsiCo reformulated Muscle Milk in 2025 to use ultra-filtered milk, removing artificial flavors and sweeteners. The reformulation is real. The question is whether the brand's regulatory track record and protein source decisions still warrant the premium it charges — particularly next to NSF-certified alternatives on the same shelf.

Transparency Score
4🔴 3🟡
Ownership DisclosureRed
Marketing-Formula AlignmentRed
Revenue Model TransparencyYellow
Ingredient DisclosureYellow
Scientific SubstantiationYellow
Label Claim VerificationRed
Risk DisclosureRed
01 Ownership Structure Red

Muscle Milk has passed through four distinct ownership structures since its founding — each representing a different strategic rationale that had little to do with sports nutrition quality and everything to do with portfolio value extraction.

1998
CytoSport — Pickett Family
Greg and Mike Pickett found CytoSport in Benicia, California. Family-run operation, early distribution partnership with PepsiCo.
2014
Hormel Foods — $450 million
Hormel — primarily a meat company — acquires CytoSport to diversify into protein. Strategic mismatch: a pork products company running a sports nutrition brand.
April 2019
PepsiCo — $465 million (Gatorade division)
PepsiCo had been Muscle Milk's distributor for years before acquiring it from Hormel. Now operates as CytoSport under the Gatorade organizational umbrella — alongside Propel and Muscle Milk RTDs.

The Gatorade placement is the structural tell. PepsiCo's sports nutrition strategy is to own the "hydration to recovery" shelf sequence: Gatorade (during), Muscle Milk (after). The protein product is a slot in a beverage portfolio strategy, not a standalone nutrition mission. This is the same pattern as Tropicana-as-orange-juice-slot and Fairlife-as-dairy-slot — the brand's nutritional positioning is instrumentalized to serve a corporate distribution and margin objective.

02 Marketing Alignment Red

The "Muscle Milk" name is the original and most persistent marketing problem. The FDA issued a formal warning letter in 2011 stating that calling the product "Muscle Milk" was misleading because it does not contain milk. The FTC had previously addressed this in 2010, requiring the label to carry "contains no milk" — but then the FDA noted that simultaneously listing milk-derived ingredients (caseinate, whey, milk protein concentrate) while saying "contains no milk" created a new contradiction, because the product does contain milk-derived ingredients. The brand got caught between two regulators with incompatible remedies.

The Name Problem
A product called "Muscle Milk" that the FDA says is misleading because it contains no milk, but that also carries an allergen warning that it contains milk-derived ingredients. The FTC said add "contains no milk." The FDA said that creates a new contradiction with the allergen statement. The brand has continued under the same name regardless. In Canada, regulators required it be sold as "Muscle Mlk" to avoid consumer confusion with dairy.

Beyond the name issue: advertising claims referred to the FTC and National Advertising Division in 2009 alleged that Muscle Milk overstated performance benefits, misrepresented nutrient quantities, and described products as "lean" that contained high levels of added fats and oils. Class action lawsuits alleged that L-glutamine was listed among ingredients but found only in trace amounts. These claims span a decade of marketing misalignment between what was said and what was in the product.

PepsiCo's 2025 reformulation — ultra-filtered milk, no artificial flavors or sweeteners — is the most significant product improvement in the brand's history. Whether it represents a genuine realignment or a trend-chasing refresh inside a legacy brand with a documented misrepresentation pattern is a legitimate question.

03 Revenue Model Yellow

Muscle Milk RTDs retail at approximately $2.50–$3.50 per bottle depending on retailer, comparable to Fairlife Core Power and below the premium tier of David and Momentous. The pricing is not predatory and the product is widely accessible at mass market retailers, convenience stores, and gym vending. PepsiCo's distribution is as wide as any brand in the database.

The yellow reflects the disconnect between price point and protein source quality. Consumers paying $3 for a "performance protein" product may not know they are getting a caseinate-and-MPC blend rather than isolate-based protein. The protein is real; the source hierarchy matters for digestion rate and amino acid absorption. That information is not front-of-pack.

04 Ingredient Integrity Yellow

The protein blend in Muscle Milk's core RTD product has historically centered on calcium caseinate, sodium caseinate, and milk protein concentrate — slower-digesting, lower-cost proteins compared to whey protein isolate or egg white. This is not false advertising in the strict sense; caseinates and MPC are legitimate protein sources. But for a brand positioned as a performance recovery product, the protein source hierarchy matters.

Protein Source
Digestion Rate
Relative Cost
Whey Protein IsolateGold standard
Fast (MPS peak 1–2hr)
High
Egg White ProteinRXBAR, Momentous
Medium-fast
High
Milk Protein ConcentrateMuscle Milk (legacy)
Mixed (whey + casein blend)
Low–Medium
Calcium / Sodium CaseinateMuscle Milk (legacy)
Slow (MPS peak 3–4hr)
Low

PepsiCo's 2025 reformulation shifts Muscle Milk to use ultra-filtered milk as its protein base — moving toward a Fairlife-style system that concentrates whey and casein more naturally through filtration rather than caseinate addition. This is a genuine improvement. The reformulated product also removes artificial flavors, sweeteners, and added colors, and delivers 26g (Base) and 42g (Pro) protein. If the current formulation reflects the 2025 reformulation, the yellow score is the appropriate current rating — an improvement from legacy, not yet at green benchmark level.

05 Scientific Backing Yellow

Caseinates and milk protein concentrate are scientifically legitimate protein sources with decades of research. The slower digestion rate of caseinate is not a problem per se — it is a different application (nighttime recovery, sustained release) than fast-digesting whey. The issue is that Muscle Milk's marketing frames the product primarily as post-workout recovery, where fast-digesting protein has the strongest evidence base. The protein science supports the ingredient; it is less well-matched to the specific use case the marketing emphasizes.

No independent scientific advisory board, no disclosed research partnerships. Endorsement by athletes (historically Adrian Peterson and others) is paid promotion, not scientific validation. The brand makes no specific clinical outcome claims, which avoids the endorser-as-scientific-validator conflict documented in the AG1 and David profiles.

06 Label Claim Accuracy Red

The documented regulatory history is the clearest record of label claim issues in the supplement category within this database. The red score is grounded in primary source enforcement actions, not inference:

FTC, 2009–2010: National Advertising Division forwarded complaints about advertising claims for possible illegal misrepresentation to the FTC and FDA. FTC closed the case in 2010 after CytoSport agreed to include "contains no milk" on labels and accept advertising concessions.

FDA Warning Letter, 2011: FDA told CytoSport the "Muscle Milk" name was misleading because the product contains no milk, while simultaneously the "contains no milk" statement contradicted the allergen disclosure that the product contains milk-derived ingredients.

Class Action — Nutrient Misrepresentation: Lawsuits alleged that L-glutamine was listed among ingredients but present only in trace amounts, and that products described as "lean" contained high levels of added fats and oils. These claims targeted label-to-product accuracy, not just advertising framing.

No equivalent enforcement action exists in the current PepsiCo era. The red score reflects the documented pattern; this dimension will be re-evaluated if the 2025 reformulation establishes a sustained clean regulatory record under new ownership.

07 Safety Transparency Red

In June 2010, Consumer Reports tested 15 protein drinks and found that two Muscle Milk powder products contained heavy metals — lead, cadmium, arsenic, and mercury — at levels at or near the United States Pharmacopeia proposed limits. The Chocolate flavor had all four heavy metals. Average cadmium levels (5.6 μg per three daily servings) exceeded the USP limit of 5 μg/day. Average lead levels (13.5 μg) exceeded the USP limit of 10 μg/day.

Heavy Metal Findings — Consumer Reports 2010
Muscle Milk Chocolate powder (three daily servings): Cadmium 5.6 μg (USP limit: 5 μg), Lead 13.5 μg (USP limit: 10 μg), Arsenic 12.2 μg (USP limit: 15 μg), Mercury detected. CytoSport disputed the methodology and cited NSF's own test results as conflicting. The Consumer Reports findings were never resolved by a definitive regulatory determination.

CytoSport disputed the findings and pointed to NSF International testing it claimed showed different results. The FDA did not issue a formal action on the heavy metal findings. The episode was not resolved by a definitive third-party determination — it remains a conflicting claims situation. Heavy metals in protein powders are an industry-wide issue related to ingredient sourcing (particularly rice protein and some dairy sources), not unique to Muscle Milk. But the Consumer Reports findings at the specific quantities reported are a documented safety transparency concern.

No NSF Certified for Sport status. No published batch COAs. For a product sold in gym settings to athletes, the absence of independent contamination testing is the same gap present in Muscle Milk as in AG1 and others — but made more significant here by the documented historical heavy metal episode.

Sources & Documentation
BevNET — FDA Warning Letter, 2011FDA told CytoSport that "Muscle Milk" name misleading (no milk in product), and that "contains no milk" label conflicts with allergen statement listing milk-derived ingredients.
Consumer Reports Protein Drink Investigation, 2010Testing of 15 protein drinks. Muscle Milk Chocolate powder: cadmium 5.6 μg/day (USP limit 5 μg), lead 13.5 μg/day (USP limit 10 μg). All four heavy metals detected.
Wikipedia — CytoSportFull regulatory history, ownership chain, FTC/FDA actions, heavy metal dispute, class action history. Verified against primary sources.
PepsiCo Acquisition Press Release, Feb 2019"PepsiCo has agreed to acquire manufacturer CytoSport from Hormel Foods Corp." $465M acquisition price. Closes April 2019.
Dairy Processing / PepsiCo Q3 20252025 reformulation: ultra-filtered milk base, Muscle Milk Base (26g protein) and Pro (42g protein), no artificial flavors/sweeteners/colors.
Sommers Schwartz — Class Action DocumentationNutrient misrepresentation lawsuits: L-glutamine listed as ingredient, found only in trace amounts; "lean" products contained high added fats. Class action allegations against CytoSport.
Dairy Processing — PepsiCo Protein Strategy, Oct 2025Reformulated Muscle Milk integrates ultra-filtered milk "for enhanced taste and a smoother, shake-like experience." Confirms no artificial flavors, sweeteners, or added colors in new formulation.