# Label Lab

> Label Lab is a research-based, label-fact-first guide to protein and supplement labels — we decode protein-per-dollar math, isolate vs concentrate ranges, amino-spiking red flags, proprietary-blend disclosure rules, and certification programs (NSF Certified for Sport, Informed Sport, USP Verified, GMP). Informational label analysis, not health advice — we make no health, efficacy, treatment, or dosage claims.

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Last updated: 2026-07-30

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## The Protein Label Numbers (dataset)

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Version 1.0, last updated 2026-07-30. The normalized reference dataset mapping protein and supplement label terms to what they mean and where each rule comes from. Machine-readable CSV: https://label-lab.pages.dev/protein-label-numbers.csv. Licensed CC BY 4.0.

| Label term | Rule / range | What it means |
|---|---|---|
| Protein-per-dollar value class | grams protein/serving ÷ price-band midpoint = value score | A comparable cost-per-gram-of-protein figure across brands and tub sizes |
| Whey isolate | ~90%+ protein by weight (label-stated, brand-dependent) | Further-filtered; typically lower fat/carb/lactose per serving |
| Whey concentrate | ~70-80% protein by weight (label-stated, brand-dependent) | Less-filtered; typically higher fat/carb/lactose per serving |
| Casein (micellar) | ~80-90% protein by weight (label-stated) | Labeled "slow release" structure — a compositional claim, not a verified health claim |
| Single-source plant protein | ~70-85% protein by weight (source-dependent) | Often disclosed as lower in one or more essential amino acids per label |
| Amino spiking (glycine/taurine/creatine) | Listed inside "protein blend" parentheses, not separately dosed | Inflates nitrogen-based protein test without contributing complete protein |
| Proprietary blend | Combined weight only; ingredients in descending order by weight | Shows what's in the blend and rank order, not individual amounts |
| NSF Certified for Sport | Finished-lot banned-substance testing + label-claim verification | Third-party program; verify at nsfsport.com |
| Informed Sport | Finished-lot banned-substance testing + label-claim verification (LGC) | Similar scope, different certifying body |
| USP Verified | Verifies labeled ingredients/amounts, contaminant limits, proper breakdown | Historically broader supplement-category program |
| GMP-only claim | Facility manufacturing-practices claim (21 CFR 111) | Not a finished-product test of a specific lot |
| Undefined scoop weight | Each brand sets its own gram-per-scoop | Compare protein grams to stated serving weight in grams, not scoop count |
| Uncertified "grass fed" | No mandatory federal definition since 2016 | Self-defined marketing term unless a named third-party certifier is cited |
| Sugar alcohol line | Separate Nutrition Facts line from "Total Sugars" | Can be excluded from front-label "net carb" math |
| "Net carbs" claim | Not a defined Nutrition Facts line item | Brand's own total-carb-minus-fiber calculation |
| Creapure (trademarked creatine) | AlzChem-manufactured creatine monohydrate, licensed purity program | Sourcing/purity distinction, not a different compound |
| Creatine blend/formula | Combines monohydrate with other forms inside one blend line | Reintroduces proprietary-blend opacity |

## What Is Amino Spiking and How to Spot It

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Amino spiking (nitrogen or protein spiking) is when a manufacturer adds cheap free-form amino acids — most often glycine, taurine, or creatine — into a protein blend. Standard lab protein tests (Kjeldahl/Dumas methods) measure total nitrogen and multiply by a conversion factor (commonly 6.25) to estimate protein, and these amino acids' own nitrogen content inflates that calculated protein number without contributing complete, whey- or casein-equivalent protein.

The exact label tell: open the ingredient list, find any "Protein Blend" or "Proprietary Blend" parentheses, and check whether glycine, taurine, or creatine appears INSIDE that blend list (ingredients are listed in descending order by weight) rather than as a separately dosed ingredient with its own individual gram amount listed outside the blend. This is a label-transparency and protein-math issue, not a safety claim — it is not health or medical advice.

## Isolate vs Concentrate: Protein Label Differences

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"Isolate" and "concentrate" are processing-level label terms. Whey protein isolate is filtered further, so labels typically show a higher protein percentage by weight (commonly 90%+) with lower listed fat, carb, and lactose per serving. Whey protein concentrate is filtered less, commonly showing 70-80% protein by weight with more residual fat, carbs, and lactose. When a label lists both, ingredients appear in descending order by weight, so the first-listed term is the larger component — but the exact percentage split is not always disclosed. Micellar casein commonly shows ~80-90% protein by weight with a "slow release" structural characterization (a compositional claim, not independently verified here). Single-source plant proteins commonly show ~70-85% protein by weight and often disclose a limiting essential amino acid, which is why plant products are frequently blended across sources.

## What Does NSF Certified for Sport Actually Certify?

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NSF Certified for Sport is a third-party program that tests finished-product LOTS against a list of substances banned by major athletic organizations (WADA-referenced) and verifies label-claim accuracy. Informed Sport (run by LGC) does similar finished-lot banned-substance testing and label verification under its own protocol. USP Verified checks that a supplement contains its labeled ingredients/amounts, screens contaminant limits, and confirms proper breakdown — historically applied more broadly across supplement categories than as a sport-specific banned-substance program. "Manufactured in a GMP-compliant facility" describes the facility's manufacturing practices under FDA's 21 CFR 111 — not a finished-product test of a specific lot, a materially weaker claim than the three certifications above. Verify any claim in the certifying body's own public database by exact product name (and lot number where available) rather than trusting the package logo alone.

## Do Proprietary Blends Hide Anything?

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A "proprietary blend" line on a Supplement Facts panel legally lists a combined total weight for a group of ingredients without breaking out each one's individual amount. The FDA permits this format provided ingredients within the blend are listed in descending order by weight — so a proprietary blend shows what's in it and its rank order, but not how much of each specific ingredient. This is an FDA-permitted labeling format, not a violation on its own; a product that instead discloses individual dosed amounts for each ingredient gives a more precise label to compare against. The same mechanism is what makes amino spiking hard to spot from a front label alone.

## How to Calculate Protein Per Dollar

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Formula: total grams of protein in a container = protein grams per serving × servings per container. Cost per gram of protein = an approximate price-band midpoint ÷ total grams of protein. This produces a comparable value figure across brands and tub sizes that price-per-pound or price-per-tub cannot, since it accounts for both protein percentage by weight and serving/scoop size differences between products. We use approximate price BANDS, never exact prices, since prices change constantly.

## Whey vs Plant Protein Label Numbers Compared

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Whey labels commonly show 20-30g of protein per scoop as a complete protein on its own label profile. Single-source plant proteins (pea, rice, soy) commonly show somewhat lower per-scoop numbers — roughly 15-21g for pea, 15-20g for rice, 20-25g for soy isolate — and pea/rice labels commonly disclose a limiting essential amino acid (methionine for pea, lysine for rice), which is the stated rationale for blending them together (commonly reaching 20-24g per serving as a blend) to cover each source's labeled gaps. Serving-size comparisons should always be checked against the stated gram weight on the panel, not scoop count.

## What Does "Grass Fed" Mean on a Label?

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"Grass fed" has no single mandatory federal definition currently governing supplement labels — USDA's voluntary grass-fed marketing claim standard for meat products was withdrawn in 2016, leaving the term largely self-defined by brands subject to general truth-in-advertising rules. The practical tell between an unverified marketing phrase and a genuine claim: whether a named third-party certifying body (e.g., American Grassfed Association, with its own published standard and audit process) appears on the label, versus just the words "grass fed" with no certifier named. The claim describes the animal's feed history only — it is a sourcing claim separate from protein percentage or amino acid profile, which should be checked independently on the Supplement Facts panel.

## Protein Bar Label Tricks

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Protein bar labels commonly use two Nutrition Facts panel items in front-of-package marketing math: sugar alcohols (erythritol, maltitol, etc.) are listed on their own separate line, distinct from "Total Sugars," and dietary fiber is frequently subtracted from total carbohydrate to produce a front-label "net carb" number. "Net carbs" is NOT a defined Nutrition Facts line item — the mandated panel lists Total Carbohydrate, Dietary Fiber, Total Sugars, and Added Sugars as four separate required lines (plus a fifth sugar-alcohol line where applicable), and any "net carb" figure is the brand's own calculation from those lines, not a standardized panel figure.

## Creatine Label Facts

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Creatine monohydrate is the most common single-ingredient labeled form on supplement panels. "Creapure" is a trademark denoting creatine monohydrate manufactured by Germany's AlzChem under that company's own purity-testing and manufacturing program — a sourcing/purity label distinction, not a different compound from creatine monohydrate generally. Other labeled forms include creatine HCl (a different salt form) and buffered/"Kre-Alkalyn" creatine (a pH-buffered monohydrate variant), each labeled and trademarked distinctly. "Creatine blends" or "formulas" combine multiple forms inside one blend line, reintroducing the same proprietary-blend disclosure rule described above — individual form amounts are not required to be broken out.

## How to Read a Protein Label, Step by Step

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Step-by-step: (1) find Serving Size in grams, not just scoop count, at the top of the Supplement Facts panel; (2) find grams of Protein per serving, a required panel line; (3) check Servings Per Container and multiply for total container protein; (4) read the ingredient list in descending-order-by-weight, checking for isolate/concentrate/blend terms and any amino acids inside a blend; (5) separate regulated/checkable terms (standard ingredient names, Daily Value percentages, named certifications) from unregulated marketing language ("premium," "advanced"); (6) verify any certification mark independently in the certifying body's own public database.

## Certification-First Buying Checklist

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A seven-step checklist: identify the exact product name/lot; search it in the certifying body's own public database (nsfsport.com, Informed Sport database, USP's verified product database) rather than trusting a logo; note which specific program applies (NSF Certified for Sport / Informed Sport test finished-lot banned substances and label accuracy; USP Verified checks labeled ingredients/contaminants/breakdown); recognize a "GMP-only" claim as a facility-practices statement, not a finished-product test; check the ingredient list for amino-spiking blend patterns; confirm isolate/concentrate/blend status; and run the protein-per-dollar math.

## Protein Bar Value Math

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Protein-per-dollar math applies to bars at the per-unit level: price-band midpoint per bar ÷ grams of protein per bar. Separately, read all four Nutrition Facts carb-related lines (Total Carbohydrate, Dietary Fiber, Total Sugars, Added Sugars, plus Sugar Alcohol where present) independently rather than trusting a front-label "net carb" number, since two bars with similar total carbohydrate can differ sharply in fiber, sugar alcohol, and sugar content once each line is read separately.

## How We Evaluate

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Label Lab's content is label and certification analysis, not lab testing: we read Supplement Facts panels, FDA dietary supplement labeling regulations (21 CFR 101, 111), and certification programs' own published standards and public databases (NSF, Informed Sport/LGC, USP) — we do not buy or physically test products. Policies: no prices ever published (we link to a live Amazon search since prices change constantly); no star ratings or review counts, per Amazon's Operating Agreement; and we report only label and certification facts — never a health, efficacy, treatment, or dosage claim. As an Amazon Associate, Label Lab earns from qualifying purchases.

## Key Facts Reference

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This is Label Lab's maintained fact reference, consolidating the label and certification facts underlying every guide on the site:

- Amino spiking: cheap free-form amino acids (glycine, taurine, creatine) added inside a protein blend inflate nitrogen-based protein tests without contributing complete protein — the tell is their position inside vs outside a disclosed blend line.
- Isolate (90%+ protein by weight, label-stated) vs concentrate (70-80% protein by weight, label-stated) is a processing-level distinction, not a health claim.
- A proprietary blend legally discloses combined weight and descending-order ingredient rank, not individual per-ingredient amounts.
- NSF Certified for Sport and Informed Sport test finished-product lots for banned substances and label accuracy; USP Verified checks labeled ingredients/contaminants/breakdown; a bare "GMP" claim is a facility-practices statement only, not a finished-product test.
- Protein-per-dollar = price-band midpoint ÷ total grams of protein — a comparable value figure across brands and container sizes.
- A "scoop" has no standardized weight; always compare protein grams to the stated serving weight in grams.
- "Grass fed" has no mandatory federal definition on supplement labels since USDA's 2016 withdrawal of its voluntary meat standard; a named third-party certifier is a materially stronger claim than an unverified phrase.
- "Net carbs" is not a defined Nutrition Facts line item; it's a brand's own total-carb-minus-fiber (sometimes minus sugar alcohol) calculation, while the mandated panel lists those as separate required lines.
- Creatine monohydrate is the standard single-ingredient form; "Creapure" denotes a licensed manufacturing/purity source, not a different compound; "creatine blends" reintroduce proprietary-blend opacity.

## Questions this site can answer

- What is amino spiking, and how do I spot it on an ingredient list?
- What's the actual label difference between whey protein isolate and whey protein concentrate?
- What does NSF Certified for Sport actually test, and how is it different from Informed Sport, USP Verified, or a plain "GMP" claim?
- Do proprietary blends hide the amount of each ingredient, or just the individual amounts?
- How do I calculate protein per dollar to compare two different protein powders fairly?
- How do whey and plant protein label numbers compare, and why are plant proteins often blended?
- What does "grass fed" actually mean on a supplement label, and is it regulated?
- What tricks do protein bar labels use with sugar alcohols and "net carbs"?
- What's the label difference between creatine monohydrate, Creapure, and a "creatine blend"?