Claims audit · Grass-fed substantiation · 4 brands

Understanding the grass-fed claim
for supplement products

In the US, "grass-fed" has no legal definition for whey — so the claim is only as strong as the evidence behind it. This is a working reference on how leading brands make the claim, where the certified ingredient actually comes from, and which certifications can legitimately back it.

Grading key A wording ≤ evidence B wording > shown evidence C wording ≫ shown evidence Green Yellow Red

FDA — misbranding

21 CFR 101.18 treats a label as misbranded if its representations — including implied ones about ingredients and origin — overstate what the evidence supports.

FTC — substantiation

Objective claims, in ads and on-pack, must be substantiated before they run. Implied takeaways count, and qualifiers have to genuinely match the proof.

The dossier

4 products · ranked best → worst

Graded on one axis: how far the on-pack wording outruns the proof shown for the grass-fed claim specifically. Note that strong purity testing (COAs, NSF) verifies what's in the tub — it does not verify how the cows were fed.

Grass-fed claim sanity — wording vs. displayed proof
Grade	Product	Claim as written	Proof shown for grass-fed	The call	Tier
A 93/100	Legion AthleticsWhey+ Grass-Fed Isolate	"Truly Grass Fed™ certified — 95% grass diet, 250 days on pasture, inspector-verified."	Named third-party cert + published standard (SDAS / Bord Bia / SGS); AGW + Non-GMO; no rBST.	Evidence exceeds the claim; wording calibrated to the standard.	Green
B 60/100	MomentousWhey Protein Isolate	"Grass-Fed… European grass-fed source." Notably never says "100%."	NSF Certified for Sport every batch — verifies purity / banned substances, not grass-fed. No named feed standard.	Restrained wording, but the grass-fed claim itself is unverified; the cert proves safety, not sourcing.	Yellow
B 55/100	Transparent Labs100% Grass-Fed WPI	"100% … exclusively sourced from grass-fed cows."	Published lot COAs — purity & protein only. No grass-fed certification.	Absolute wording outruns proof; front panel even exceeds its own "access to pasture" body copy.	Yellow
C 30/100	Paleovalley100% Grass-Fed Whey + Colostrum	"100% grass fed and NEVER fed grains," plus stacked immune / gut / hormone claims.	None shown. FDA disclaimer present; page admits the term is undefined.	Most absolute wording, least proof; "never grains" forecloses the exceptions a real standard allows.	Red

At a glance

Side by side

Grass-fed substantiation — what's displayed on the public page
Criterion	Legion	Momentous	Transparent Labs	Paleovalley
Grade	A	B	B	C
Headline claim	Certified, qualified	Grass-fed, not 100%	100% / exclusive	100% / never grains
3rd-party grass-fed cert	Yes — named	No (NSF ≠ grass-fed)	None shown	None shown
Proves the sourcing claim?	Yes — cert + standard	No (sport cert only)	No (purity only)	No (nothing)
Wording vs. evidence	Evidence exceeds	Modest, unproven	Outruns	Far outruns
Stacked extra claims	Backed by certs	Light	Moderate	Heavy

Sourcing routes

Certified vs. self-declared

For a grass-fed claim, two ingredient routes are on the table. On a bag they look identical — both say "grass-fed" — but the evidence behind them is not in the same league. Side by side, on each supplier's own documentation:

Truly Grass Fed™ vs. Actus grass-fed WPI — on the suppliers' own specs
What you're comparing	Truly Grass Fed™ (Tirlán)🇮🇪 Ireland	Actus — Grass-Fed WPI 90🇺🇸 mfd · spec PIN 104384
Forage standard	≥95% forage diet; ≤5% concentrate	"Grass and other forage," but "may also include… grains" — no % defined
Pasture	250 days/yr (3-yr herd average)	"May or may not be continuous" — none specified
Dairy origin	Single-origin Ireland (SE catchment)	Multi-country blend — up to 12 countries (AU, NZ, IE, EU… and/or USA)
Independent grass-fed verification	SDAS / Bord Bia / SGS (ISO 17065), audited every 18 mo	None — a good-faith supplier feed statement, "not warranted"
Hormones	No rBST / growth hormones	rBGH-free (supplier signed statements)
Non-GMO	Non-GMO Project Verified (3rd-party)	Non-GMO / Identity-Preserved (self-documented)
Animal welfare	Animal Welfare Approved (AGW)	Not addressed
Grass-fed claim it can back	Certified "95% grass-fed, 250 days on pasture"	Self-asserted "grass-fed" only — no standard, blended origin

Read: both can legitimately print the word "grass-fed," but only Truly Grass Fed ties it to a defined percentage, pasture days, a single origin, and an independent audit. The Actus grass-fed spec is a self-declared feed statement from a multi-country blend — which sits closer to the commodity tier below than to a certified hero claim.

Also evaluated — no certified grass-fed standard

These came up earlier in sourcing and all three land Red for an unqualified grass-fed claim: none offers a defined forage standard, named exclusions, or independent certification. Fine as commodity WPI — but sourcing here caps your label at a qualified, amber-tier claim, not a certified hero claim.

Considered suppliers — why they can't anchor a certified claim
Supplier	Documentation on hand	Why it can't carry the certified claim	Tier
"Milky Whey"The Milky Whey + Wisconsin Whey Protein	Standard supplier whey specs	No defined forage standard, exclusions, or independent grass-fed certification.	Red
Mill Haven FoodsNew Lisbon, WI · US	200 IWPI w/SFL spec + "Feed Statement 200" (a disclaimer, not a standard)	Diet "may also include… grains"; pasture not continuous; supplier disclaims grass-fed and shifts all claim liability to the brand via indemnity.	Red
Mullins Whey5th-gen WI · single-source	9060/9010 specs, Feed Statement, FARM program; 100% traceability; rBGH/rBST-free (2017)	Feed is grass "supplemented with… grains"; the supplier itself states grass-fed here is an unverified marketing claim. No forage % or independent cert.	Red

Mill Haven — read the indemnity clause Its rep markets the 200 WPI as "the product many brands… use to support their grass-fed claims" — but Feed Statement 200 is a liability shield, not a standard. It concedes the diet "may also include… grains," pasture "may or may not be continuous," there's "no U.S. regulatory standard," and Mill Haven "does not certify or guarantee 'grass fed' status." Then it pushes 100% of the risk onto you: the brand owner must substantiate the claim and indemnify Mill Haven against any liability arising from it. Solid US/WI WPI (≥89.5% protein, Kosher/Halal/EU) — but on grass-fed it hands you the label and all the exposure.

Mullins — the honest red Red for grass-fed, but the strongest of these for an honest claim: 100% farm-to-finished traceability, rBGH/rBST-free since 2017, single-origin Wisconsin whey from its own cheese (no blend), FARM-program farms, ~$14.50/lb at pallet MOQ with 2 lb samples. Their rep said it plainly — "grass-fed is a marketing claim, not a standard or verified by an independent organization" — which is exactly this page's thesis. If you pivot off grass-fed, Mullins can strongly back "rBST-free, fully traceable US whey" instead.

AGN Roots — paused

A Greener World–certified Irish grass-fed WPI, but new wholesale/affiliate onboarding has been paused since early 2025 over tariff and cost uncertainty. Existing partners handled case-by-case.

American Grassfed (AGA) — different path

A US-origin certification route, not an ingredient supplier. Built around US family farms, so it likely can't cover imported whey — and may certify producers rather than finished powders. Confirm the level it attaches at first.

The certification landscape

What each label actually requires

The US has had no federal grass-fed standard for dairy since the USDA withdrew its grass-fed marketing claim in 2016 — which is exactly why a named third-party scheme is what turns "grass-fed" from a marketing word into a defensible claim. The top three rows are true grass-fed certifications; the rest are adjacent labels that prove other things.

Grass-fed & adjacent certifications — side by side
Certification	Forage diet	Pasture & welfare	Hormones / antibiotics	Verification	Fits a whey/WPI claim?
American Grassfed (AGA)🇺🇸 USA-only · farm/producer	100% forage, lifetime; no grain ever	Pasture, no confinement	None added — prohibited	Independent on-farm audit every 12–15 mo	Only if your milk is from US family farms — can't cover imported Irish whey. Certifies producers + licenses the mark.
Truly Grass Fed™ (Tirlán)🇮🇪 Ireland · ingredient brand	≥95% forage (≤5% concentrate); 3-yr herd avg	250 days/yr pasture + AGW welfare	No rBST / growth hormones	SDAS / Bord Bia / SGS (ISO 17065), every 18 mo	Yes — built as a branded ingredient designed to go on finished products. The realistic WPI route.
Certified Grassfed by AGW🇺🇸🇨🇦 A Greener World · farm	100% grass/forage, lifetime; no grain	Outdoors on pasture; AWA welfare prerequisite	None — prohibited	Independent on-farm audit (IOAS-accredited)	Strongest US-side standard; has a processor/distributor label path, but still farm-anchored + US/Canada.
Adjacent labels — not grass-fed certifications
USDA Organic🇺🇸 federal · operation/product	Grain allowed — not grass-fed	≥120 days grazing; ≥30% intake from pasture	No synthetic hormones/antibiotics	USDA-accredited certifier, annual	Proves organic, not grass-fed. Doesn't substantiate the forage claim.
Non-GMO Project Verified🌐 ingredient/product	n/a — GM avoidance only	n/a	n/a	Non-GMO Project, annual renewal	Useful bundled add-on; says nothing about grass-fed.
NSF Certified for Sport🌐 finished product · per batch	n/a — purity / banned substances	n/a	n/a	NSF, every batch	Proves what's in the tub, not how cows were fed (this is Momentous's cert).

Bottom line for a WPI brand: the only labels that actually back "grass-fed" are the top three. AGA and AGW set the higher bar (100% forage) but are anchored to US/Canada family farms, so they fit a domestically sourced product — not imported Irish whey. Truly Grass Fed sits at 95% but is the one purpose-built to be licensed onto a finished ingredient. Your sourcing decision and your certification are therefore the same decision.