Two premium clean-label brands serving the same shopper: the lifter who would rather pay 40 percent more for grass-fed whey, no artificial sweeteners and a fully-disclosed label. Promix from American family farms vs Transparent Labs from grass-fed Irish dairy. We tracked every retailer.
Promix Nutrition was founded in 2011 in Charlotte, North Carolina and built its catalog around a simple sourcing thesis: small American family farms, grass-fed cows, cold-processed whey. The brand is small-team, often direct-to-consumer, and has avoided big-box retail in favor of subscribe-and-save bulk orders. Promix sells Grass-Fed Whey Isolate, Vegan Plant Protein, Grass-Fed Whey Concentrate, Clear Protein and a Mass Gainer line. The 5 lb tub is the volume product. The brand's biggest selling point: more whey per scoop than nearly any competitor, sweetened with stevia and monk fruit, no artificial anything.
Transparent Labs launched in 2012 out of Utah with the strongest commitment to lab transparency in the industry. The brand publishes third-party Certificates of Analysis for every batch, refuses to use proprietary blends or artificial colors, and sources its grass-fed whey from Irish dairy farms. The catalog spans ProteinSeries 100% Grass-Fed Whey, Whey Isolate, Casein, Mass Gainer and a full pre-workout and recovery lineup. Transparent Labs is sold direct only (transparentlabs.com) and has stayed out of Amazon to maintain pricing control. Premium tier, premium positioning, no compromise.
| Metric | Promix Grass-Fed Whey Isolate (5 lb) | Transparent Labs 100% Grass-Fed Whey (2.5 lb) |
|---|---|---|
| Tub size | 2,270 g / 5 lb | 1,134 g / 2.5 lb |
| Servings per tub | 74 | 30 |
| Protein per serving | 25 g | 28 g |
| Serving size | 30 g | 38 g |
| Total protein in tub | 1,850 g | 840 g |
| Sweetener | Stevia, monk fruit | Stevia |
| Sourcing | US grass-fed dairy | Irish grass-fed dairy |
| Lowest tracked price | $89.99 direct | $59.99 direct |
| Cost per serving | $1.22 | $2.00 |
| Cost per gram of protein | $0.048 | $0.070 |
| Best flavor | Dutch Chocolate, Vanilla Bean | Mint Chocolate Chip, Milk Chocolate |
If grass-fed whey is your only criterion and you want the most protein for the lowest cost, Promix is the smarter buy. The 5 lb bulk option gives Promix a 30-plus percent per-gram cost advantage versus Transparent Labs's 2.5 lb tub. Across a year of daily use, that gap works out to roughly $150-200 in savings.
Transparent Labs justifies its premium with a higher protein-per-scoop density (28 g vs 25 g), the more transparent lab testing process, and unique flavor distinctions. If you treat your protein as a clinical-grade supplement (the way you treat a fish oil or a multivitamin), Transparent Labs's testing rigor and Irish dairy sourcing read as worth the premium. If you treat your protein as a daily training fuel, the Promix value wins.
Both brands sweeten with stevia and monk fruit, so neither delivers the dessert-shake hit you get from sucralose-sweetened brands like Optimum or Dymatize. Adjusting expectations matters.
Promix Dutch Chocolate is mainstream-palatable, lightly sweetened and works in a shaker with water or milk. Vanilla Bean is the strongest in the lineup and arguably the best stevia-sweetened vanilla on the US market.
Transparent Labs leans cleaner and slightly more polarizing. Milk Chocolate is good but not great; the standout flavors are Mint Chocolate Chip and Cinnamon French Toast, which deliver flavor complexity that other clean-label brands struggle with. The standard chocolate can taste "thin" if you are coming from a Whey Plus product, but daily-drinkers usually adjust within a week.
If your default shake is a daily training scoop and you want grass-fed whey at the lowest price-per-gram, buy Promix Grass-Fed Whey Isolate 5 lb. The Dutch Chocolate or Vanilla Bean flavors are mainstream-palatable and the bulk size means you reorder less often. The brand's subscribe-and-save program drops the per-tub cost meaningfully.
If lab transparency is a non-negotiable for you, you want a unique flavor like Mint Chocolate Chip, or you simply prefer the slightly leaner 28 g per scoop macros, buy Transparent Labs 100% Grass-Fed Whey. The premium is real but the product is the cleanest-tested grass-fed whey on the market.
If you cannot decide: start with a 2.5 lb Transparent Labs to confirm the clean-label flavor works for you. If you stick with it for a month, switch to Promix 5 lb for the bulk savings going forward. Combined first-month cost about $90 and you get a clear data point on whether stevia-sweetened whey fits your palate.
Transparent Labs ProteinSeries products are Informed-Protein certified (a UK-based banned-substance testing program) but not NSF Certified for Sport. Promix is third-party tested but not Informed-Sport or NSF certified. If you compete in a tested federation that requires NSF for Sport, look at Ascent or Klean Athlete.
The Promix Grass-Fed Whey Isolate IS the isolate option (filtered to remove most lactose). The brand also sells a Grass-Fed Whey Concentrate variant at a slightly lower price for shoppers who do not need the isolate processing. The concentrate is what most clean-label whey brands actually sell when they say "grass-fed whey"; Promix differentiates by labeling both clearly.
The brand has held the line on no-Amazon distribution since 2014 to maintain pricing control and avoid the counterfeiting problem that affects most clean-label supplements on Amazon. Subscribe-and-save through transparentlabs.com offers 10% off and free shipping on orders over $99. The trade-off: you wait 3-5 business days for shipping vs Prime same-day.
Yes for both. Promix Vegan Plant Protein uses a pea + rice + sacha inchi blend (24 g protein per scoop). Transparent Labs Organic Vegan uses a pea + rice blend (24 g protein, USDA Organic certified, the highest organic certification you can get in a vegan protein). The Transparent Labs vegan is the cleaner label of the two but Promix's plant blend has more flavor variety.
Promix launched in 2011, Transparent Labs in 2012. Both are over a decade into operations and have built loyal customer bases through quality consistency. Neither brand has gone through corporate acquisition or major formula changes; what you buy today is largely the same product the brand has been selling for years.