Protein powder is the most crowded shelf in sports nutrition, and most tubs hide behind proprietary blends, artificial sweeteners, and labels that read like chemistry homework. Transparent Labs built its brand on the opposite bet: fully disclosed labels with nothing to hide. Its Grass-Fed Whey Protein Isolate in Chocolate Peanut Butter promises 28 grams of protein per serving from a short, clean ingredient list — sweetened with stevia and monk fruit, with no artificial sweeteners, colors, or preservatives.
This review breaks down the label — the 28g protein claim, the four-ingredient formula, the grass-fed sourcing — what the brand claims, what lifters report, and the honest complaints: the premium price, the stevia taste divide, and the clumping that can come with a lecithin-free formula. Nothing here is based on hands-on testing; it is the label, the brand’s claims, and buyer reports, examined.
Product at a Glance
| Detail | Spec |
|---|---|
| Photo |  |
| Product | Transparent Labs Grass-Fed Whey Protein Isolate, Chocolate Peanut Butter |
| Key Specs |
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| Best For | Lifters who want a clean-label, high-protein isolate and will pay a premium for minimal ingredients |
| Check Price on Amazon | |
What This Protein Is
Transparent Labs Grass-Fed Whey Protein Isolate is exactly what the name says: a whey protein isolate — the most filtered form of whey, with most of the fat and lactose removed — sourced from grass-fed cows. The Chocolate Peanut Butter flavor reviewed here is one of the brand’s most popular. Each tub holds 30 servings, and each serving is built around a single goal: as much protein as possible with as little else as possible.
The positioning is clean-label premium. Where mass-market proteins bulk out their formulas with gums, creamers, and artificial flavors, this one keeps the ingredient list to four items. That minimalism is the product’s identity — and, as we’ll see, the source of both its appeal and its quirks.
The Label, Up Close
The headline number is 28 grams of protein per serving, with 1 gram of fat and 1 gram of sugar. For an isolate, that’s a strong protein-to-calorie ratio — the whole point of choosing isolate over concentrate is getting more protein with less of everything else, and 28g delivers.
The ingredient list is strikingly short: grass-fed whey protein isolate, natural flavors, stevia extract, and monk fruit extract. No artificial sweeteners, no artificial colors, no preservatives, no gums, no lecithin. The brand lists exact amounts rather than hiding behind proprietary blends, and the product undergoes third-party testing for purity — two transparency practices that set it apart in a category famous for opacity.
The absence of lecithin and gums is a deliberate clean-label choice with a practical consequence: lecithin is an emulsifier that helps powder dissolve, and gums thicken the shake. Without them, the formula is purer — and potentially clumpier. More on that below.
What the Brand Claims
Taken as the brand’s claims: Transparent Labs says each serving delivers 28 grams of protein from grass-fed whey isolate, and that the product goes through batch-level third-party testing. The grass-fed claim refers to the sourcing of the whey; the testing claim refers to independent verification of what’s in the tub. Both are about transparency rather than transformation — this is a protein powder, not a promise.
What We Like
28 grams of protein with a very short ingredient list. High protein plus minimal ingredients is a rare combination. Most isolates that hit 28g do it with a longer list of additives; this one keeps it to four ingredients.
Genuine label transparency. Exact amounts are listed — no proprietary blends, no “matrix” hiding the doses. In sports nutrition, that openness is still the exception rather than the rule.
Mixes well and tastes good. The Chocolate Peanut Butter flavor gets consistent praise from buyers for tasting like an actual treat rather than a chore. For a stevia-sweetened isolate, that’s an achievement.
Third-party tested for purity. Independent testing of what’s in the tub is a meaningful quality signal in a loosely regulated category.
Honest Complaints
Premium price. At roughly $2 per serving based on prices observed at the time of writing, this is priced well above budget proteins. You’re paying for the short label and the testing — whether that’s worth it depends on how much you value clean ingredients.
The stevia taste doesn’t suit everyone. Stevia has a distinctive aftertaste that some people notice and dislike. If you’ve bounced off stevia-sweetened products before, this one won’t convert you.
Potential clumping without lecithin. The flip side of the clean label: without lecithin as an emulsifier, some users report clumping. A good shaker bottle and enough liquid help, but it may never mix as effortlessly as formulas built for mixability.
Only 30 servings per tub. At a premium per-serving price, a 30-serving tub runs out fast for daily users — this is a product you rebuy often.
Not dairy-free. It’s whey — obvious, but worth stating plainly for anyone scanning for a dairy-free option. This isn’t it.
Red Flags to Know
Contains dairy. Whey protein isolate still contains dairy and trace lactose. It’s not suitable for anyone with a dairy allergy, and some people with lactose intolerance still react to isolates despite the reduced lactose.
Some users report digestive issues. Bloating, cramping, and GI discomfort show up in buyer reports — common with protein powders generally, but worth knowing before you commit to a full tub.
Check with a professional if it applies to you. If you’re on medication or managing a health condition, consult a healthcare professional before adding a high-protein supplement to your routine — as with any supplement.
A Note Before You Buy
Protein powder is a supplement, not a shortcut: it helps if you’re not getting enough protein from food, and it won’t do much if you already are. If you have a dairy allergy, lactose intolerance, or a medical condition — or you’re taking medications — talk to a healthcare professional before use.
The Verdict
Transparent Labs Grass-Fed Whey Protein Isolate is the clean-label isolate done right: 28 grams of protein, a four-ingredient label with exact amounts, no artificial anything, and third-party testing to back it up. The Chocolate Peanut Butter flavor earns its praise, and the transparency is genuine.
The trade-offs are the price (roughly $2 a serving), the stevia taste that divides people, and the occasional clumping that comes with skipping lecithin. If you want maximum protein with minimum ingredients and you’re willing to pay for it, this is a strong pick. If you want the cheapest protein per dollar — or you know stevia isn’t for you — the budget aisle has options.
How much protein per scoop?
Each serving delivers 28 grams of protein from grass-fed whey protein isolate, with 1 gram of fat and 1 gram of sugar. That high protein-to-calorie ratio is the main reason to choose an isolate over a concentrate.
Is it grass-fed?
Yes — the whey protein isolate is sourced from grass-fed cows, per the brand. The product is also third-party tested for purity.
Does it mix well?
Most buyers report good mixability and praise the Chocolate Peanut Butter flavor. Because the formula contains no lecithin or gums, some users report occasional clumping — a shaker bottle and enough liquid help.
How many servings are in a tub?
Each tub contains 30 servings. At a premium per-serving price, daily users will go through a tub in about a month.
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