Protein Powder Brands Compared: Naked Whey vs. Naked Casein vs. Vital Proteins vs. KOS vs. Levels

Protein coffee — proffee, protein lattes, protein cold brew — is only as Ingredient-Honest as the protein powder stirred into it, and “protein powder” covers a wider range of actual ingredient lists than most people assume. Our Ingredient-Honest Registry has now checked eight SKUs across four real brands against our 16-point standard, and the findings split sharply: four clear the bar on nothing but a single named protein source (or, in one case, two clean ingredients), and four fail on specific, named additives — including one brand that fails even in a SKU marketed as “organic” and “clean,” and a second brand that fails specifically because its sweetening system isn’t one this site currently grades as a Pass. This is the real brand-by-brand comparison, same template as our Almond, Oat, and Rice milk shootouts.

The Eight SKUs, Compared

Brand	Cost / serving	Calories / serving	Protein / serving	Ingredients	Ingredient-Honest Verdict
Naked Whey (Unflavored)	~$1.80	120	25g	Grass-fed whey protein concentrate	Pass
Naked Casein (Unflavored)	~$1.67	130	26g	Micellar casein (cold-processed)	Pass
Vital Proteins Collagen Peptides (Plain)	~$1.93	70	18g	Collagen peptides (hydrolyzed bovine collagen)	Pass
Levels Grass-Fed Whey (Unflavored)	~$1.61	130	24g	Whey protein concentrate, sunflower lecithin	Pass
Vital Proteins Collagen Peptides (Vanilla)	~$1.68	80	18g	Collagen peptides, maltodextrin, sea salt, natural flavors, stevia sweetener	Fails
KOS Organic Plant Protein (Vanilla)	~$2.60	150	20g	Pea/pumpkin/quinoa/chia protein blend, organic superfoods blend (incl. acacia gum), coconut sugar, vanilla flavor, natural flavor, stevia leaf extract, monk fruit extract	Fails
Levels Grass-Fed Whey (Pure Chocolate)	~$2.07	130	24g	Whey protein concentrate, cocoa powder, sunflower lecithin, sea salt, stevia leaf extract, monk fruit extract	Fails
Levels Grass-Fed Whey (Vanilla Cinnamon)	~$2.07	130	24g	Whey protein concentrate, sunflower lecithin, vanilla extract, cinnamon, natural vanilla flavor, stevia leaf extract, sea salt, monk fruit extract	Fails

A sourcing note on these numbers, following the same discipline our milk brand comparisons use: Vital Proteins’ two figures, the KOS figure, and all three Levels figures are confirmed directly against manufacturer/retailer product pages checked October 8, 2026 — Levels’ $1.61/serving unflavored price is Walmart’s listed price (Levels’ primary retail partner as of an August 2026 nationwide rollout); the two flavored Levels SKUs are priced from a direct Vitacost fetch ($57.99/28 servings) since we couldn’t confirm a flavor-specific Walmart listing, though Walmart prices same-size Levels flavors we did confirm (e.g. Cappuccino) at the same $44.99 as Unflavored, so the real price may run closer to $1.61 than $2.07 — confirm before buying. Naked Whey’s and Naked Casein’s price figures carry a softer sourcing caveat — we couldn’t pull full product detail directly from nakednutrition.com’s own pages, so those two cost figures are aggregated from independent retailer and review-site listings rather than a direct manufacturer source. The ingredient claims for both (single-ingredient, unflavored) are well-corroborated across multiple independent sources and not in doubt; it’s specifically the price figures carrying the caveat. Confirm current pricing directly before relying on it for a purchase decision.

Naked Whey (Unflavored)

What’s in it: Grass-fed whey protein concentrate. One ingredient. No lecithin, no gums, no flavoring of any kind.

Ingredient-Honest verdict: Pass, and the most straightforward single-ingredient pick of the five.

Cost, calories, protein: ~$1.80/serving (2 scoops, 30g), 120 calories, 25g protein — the highest protein-per-calorie ratio of the three Pass brands, which tracks with whey’s reputation as a fast-digesting, high-leucine protein source.

Naked Casein (Unflavored)

What’s in it: Micellar casein, cold-processed to preserve its slow-digesting micelle structure. One ingredient, same single-ingredient discipline as Naked Whey from the same brand.

Ingredient-Honest verdict: Pass.

Cost, calories, protein: ~$1.67/serving, 130 calories, 26g protein — the highest raw protein count of the five, at a similar price to the other Pass brands.

Vital Proteins Collagen Peptides (Plain/Unflavored)

What’s in it: Collagen peptides — hydrolyzed collagen sourced from grass-fed, pasture-raised bovine hide. One ingredient, confirmed directly on vitalproteins.com’s own product page.

Ingredient-Honest verdict: Pass. Worth naming plainly: collagen is an incomplete protein (it lacks tryptophan and is lower in several other essential amino acids than whey or casein), so it’s not a direct nutritional swap for the other two Pass brands here — it’s a Pass on ingredient cleanliness, not a claim that it’s nutritionally interchangeable with whey or casein.

Cost, calories, protein: ~$1.93/serving (20g, 2 scoops), 70 calories, 18g protein — the lowest calorie count of the five, which also makes it the lowest protein-per-serving of the three Pass brands.

Vital Proteins Collagen Peptides (Vanilla, flavored)

What’s in it: Collagen peptides, maltodextrin, sea salt, natural flavors, and a stevia sweetener.

The same-brand warning that matters here, carried over from our registry: this is the exact same collagen base as the Pass brand directly above it, from the same company, under a near-identical name. The only difference is four added ingredients for flavor. Ingredient-Honest verdict: Fails, specifically on maltodextrin (a processed starch, not a whole-food ingredient), unspecified “natural flavors” (Criterion 5), and the added stevia sweetener. Check for “unflavored” or “plain” specifically on the label — “Vital Proteins Collagen Peptides” alone isn’t enough to know which formulation you’re getting.

Cost, calories, protein: ~$1.68/serving (23g, 2 scoops), 80 calories, 18g protein, 3g carbs, 0g sugar — the 0g sugar figure is doing real marketing work here, since the carbs are still coming from maltodextrin and the sweetness from stevia, not from the “clean” collagen the brand name leans on.

Levels Grass-Fed Whey (Unflavored)

What’s in it: Whey protein concentrate, sunflower lecithin. Two ingredients, confirmed directly off the printed label.

Ingredient-Honest verdict: Pass. Sunflower lecithin is a minor emulsifier added to help the powder mix, not a gum/thickener/stabilizer, so it doesn’t trip the same criterion that fails KOS below. Levels also markets grass-fed, hormone-free dairy sourcing — a stronger hormone-sourcing claim than we have confirmed for Naked Whey, for what it’s worth if that specific point matters to you.

Cost, calories, protein: ~$1.61/serving (1 scoop, 32g) at Walmart, Levels’ primary retail partner, 130 calories, 24g protein — essentially tied with Naked Whey and Naked Casein on all three numbers.

Levels Grass-Fed Whey (Pure Chocolate and Vanilla Cinnamon, flavored)

What’s in it: Pure Chocolate: whey protein concentrate, cocoa powder, sunflower lecithin, sea salt, stevia leaf extract, monk fruit extract. Vanilla Cinnamon: whey protein concentrate, sunflower lecithin, vanilla extract, cinnamon, natural vanilla flavor, stevia leaf extract, sea salt, monk fruit extract. Both confirmed directly off the printed label.

Ingredient-Honest verdict: Fails, both SKUs — and it’s a different kind of fail than Vital Proteins’ or KOS’s, worth naming precisely rather than lumping in with “has additives.” Nothing here is an alarming ingredient: real cocoa, real named vanilla extract and cinnamon, no artificial dyes, no seed oils, no synthetic preservatives. The problem is the sweetening system. Both flavored SKUs rely entirely on stevia leaf extract and monk fruit extract, and per our own Sweeteners Compared page, monk fruit/stevia blends are a separate, currently-ungraded tier on this site — not one of the five sweeteners (maple, honey, raw cane sugar, coconut sugar, dates) that can earn a Criterion-1 Pass. That alone keeps both SKUs out of Pass territory regardless of anything else on the label. Vanilla Cinnamon has a second, independent problem on top of that: it lists “natural vanilla flavor” alongside its vanilla extract, a direct Criterion 5 violation, and that vanilla extract itself isn’t labeled “pure,” so it doesn’t clear Criterion 6 either.

Cost, calories, protein: ~$2.07/serving at the directly-confirmed Vitacost price ($57.99/28 servings) — though same-size Levels flavors we did confirm at Walmart (e.g. Cappuccino) price identically to Unflavored at $44.99, which would put the real per-serving cost closer to $1.61 — 130 calories, 24g protein for both flavors.

KOS Organic Plant Protein (Vanilla)

What’s in it: A plant protein blend (pea protein, flax seed, quinoa, pumpkin seed protein, chia seed) plus an “organic superfoods blend” that includes coconut milk, inulin, acacia gum, apple, carrot, cranberry, orange, broccoli, shiitake mushroom extract, and tomato — then, in the Vanilla SKU specifically, coconut sugar, vanilla flavor, natural flavor, sea salt, stevia leaf extract, and monk fruit extract on top of that base.

Ingredient-Honest verdict: Fails, and the most layered fail of the five. The acacia gum is in KOS’s base superfoods blend, which ships in every flavor of this product line including the unflavored/unsweetened SKU — meaning KOS fails Criterion 4 (added gums) before flavoring even enters the picture. The Vanilla SKU then stacks an unspecified “natural flavor” (Criterion 5) and a stevia leaf extract on top. Worth naming directly: KOS markets this line on being organic and clean-label, and the organic claim itself checks out — but organic sourcing doesn’t change what acacia gum is structurally doing in the formulation, the same lesson our milk research already found with Rice Dream’s organic canola oil and Aroy-D’s organic coconut milk, both of which still failed on added stabilizers despite organic certification.

Cost, calories, protein: ~$2.60/serving (2 scoops, 1.2 lb container, 15 servings), 150 calories, 20g protein — the priciest and most calorie-dense serving of the five, and the only plant-based option in this lineup.

Which One Should You Actually Buy?

• Cleanest ingredient list, highest protein per serving: Naked Casein (26g) is the single highest, with Naked Whey, and Levels Unflavored all landing around 24-25g at a nearly identical price point — genuinely a toss-up between those three if you want unflavored whey/casein specifically.
• Want collagen specifically (skin/joint-support framing, not a whey/casein replacement): Vital Proteins Collagen Peptides, plain/unflavored only — skip the Vanilla SKU from the same brand entirely.
• Already buy Levels and want the clean SKU: get Unflavored specifically. Both Pure Chocolate and Vanilla Cinnamon fail the standard — not on anything alarming, but because their stevia/monk-fruit sweetening system isn’t one this site currently grades as Ingredient-Honest, and Vanilla Cinnamon additionally lists “natural vanilla flavor.” If you want the chocolate or vanilla taste and still want an IH Pass, buy Unflavored and add your own verified-clean flavor (real cocoa powder and a splash of pure vanilla extract get you most of the way there).
• Want a flavored protein powder that’s actually Ingredient-Honest: none of the eight SKUs checked so far. Every flavored option here fails on at least one named issue. The honest workaround is buying an unflavored Pass brand (Naked Whey, Naked Casein, Vital Proteins Plain, or Levels Unflavored) and building your own flavor from a separately-verified clean extract or syrup (see our Ingredient-Honest Registry’s Extracts & Sweeteners sections) — exactly how our Ingredient-Honest protein coffee recipes are built.
• Want a plant-based option: KOS is the only plant-based brand we’ve checked so far, and it fails on acacia gum even in its unflavored form — we haven’t yet found a clean plant-based protein pick, the same “no clean commercial option exists yet” finding our rice milk research landed on.
• Cost is the only thing that matters: Levels Unflavored at ~$1.61/serving (Walmart) is the cheapest Pass brand here, just ahead of Naked Casein’s ~$1.67 — both genuinely clean, so this one’s a real tiebreaker if price is your deciding factor.

FAQ

Why does Vital Proteins have both a Pass and a Fail product?

Because “Vital Proteins Collagen Peptides” (plain) and “Vital Proteins Collagen Peptides, Vanilla” are two different formulations sold under a near-identical name from the same brand — the same pattern our registry has now found repeatedly (Califia’s two almond milks, Oatly vs. Elmhurst). Only the plain/unflavored version is a single ingredient. The Vanilla version adds maltodextrin, natural flavors, and stevia. Always check for “unflavored” or “plain” specifically.

Is collagen a good substitute for whey or casein in protein coffee?

Not nutritionally — collagen is an incomplete protein (it’s missing tryptophan and lower in several other essential amino acids), so it’s not interchangeable with whey or casein gram-for-gram if complete amino acid coverage matters to you. It’s a real, clean, Ingredient-Honest option on its own terms, just not a direct swap-in replacement.

Is there a clean flavored protein powder you’d recommend?

Not among the eight SKUs we’ve checked so far — every flavored SKU in this comparison fails on at least one named issue (maltodextrin, an unspecified “natural flavor” line, acacia gum, or a sweetening system built entirely on stevia/monk fruit, which this site doesn’t currently grade as Ingredient-Honest). The honest workaround is buying an unflavored Pass brand and adding your own verified-clean flavor (vanilla extract, maple syrup, etc.) rather than relying on a flavored protein powder to do that work.

Does “organic” mean a protein powder is automatically Ingredient-Honest?

No — KOS Organic Plant Protein is a direct counterexample. Its organic certification is real and accurate, but the product still fails our standard because of acacia gum, an added stabilizer, which is present regardless of organic sourcing. The same disconnect shows up elsewhere in our registry (Rice Dream’s organic canola oil, Aroy-D’s organic coconut milk) — organic answers a different question (how the ingredient was farmed) than Ingredient-Honest does (whether an ingredient belongs in the formulation at all).

Which of these is best for proffee or a protein cold brew specifically?

Naked Whey is the most common choice for cold protein drinks — it’s fast-digesting, mixes reasonably well cold, and is a clean single ingredient. Our Ingredient-Honest Registry names it as the protein-powder substitution to reach for across our protein-coffee recipes for exactly that reason. Unflavored Levels Grass-Fed Whey is an equally clean, nearly identically priced alternative if you already have that brand on hand.

Why do Levels’ Chocolate and Vanilla Cinnamon fail if the Unflavored version passes?

Not because of any artificial ingredient — both flavors use real cocoa powder, real vanilla extract, and real cinnamon, with no artificial dyes, seed oils, or synthetic preservatives. They fail specifically because both sweeten entirely with stevia leaf extract and monk fruit extract, a sweetening system this site’s own Sweeteners Compared page already treats as a separate, ungraded tier rather than one of the five sweeteners that can earn an Ingredient-Honest Pass. Vanilla Cinnamon has a second, independent issue on top of that: it lists “natural vanilla flavor” alongside its vanilla extract, which trips our standard’s ban on vague flavor wording regardless of the sweetener question.