The "Proprietary Blend Tax" Is Costing You More Than Money
We analyzed 14 best-selling pre-workouts. Here's the math on what hiding doses actually costs you — and which brands are the worst offenders.
What Is a Proprietary Blend?
A proprietary blend is a supplement industry loophole that allows brands to list ingredients on their label without disclosing individual doses.
FDA regulations require that the total weight of a blend be listed. Individual ingredient amounts within it remain hidden. The brand can call it anything: "Performance Matrix," "Energy Complex," "Neuro Drive Formula" — the name doesn't matter. What matters is that you, the consumer, have no way to verify whether the doses are effective.
This is legal. It is also, in our view, a fundamental act of consumer dishonesty.
The Mathematics of Hiding Doses
Here is the economic logic a supplement brand faces:
L-Citrulline (effective dose: 6–8g) costs approximately $0.04–0.06 per gram. Beta-Alanine (effective dose: 3.2g) costs approximately $0.02–0.03 per gram. Caffeine anhydrous (effective dose: 150–200mg) costs approximately $0.002 per gram. Creatine monohydrate (effective dose: 3–5g) costs approximately $0.02–0.04 per gram.
To fully dose a pre-workout with L-Citrulline at 6g, Beta-Alanine at 3.2g, and Caffeine at 200mg, the raw ingredient cost is approximately $0.38–0.58 per serving.
Now consider a proprietary blend labeled "Pre-Workout Matrix: 7,500mg":
- Creatine (cheap filler, $0.025/g): 4,000mg — $0.10
- Beta-Alanine: 1,500mg (below effective dose) — $0.04
- L-Citrulline: 1,200mg (well below 6g effective dose) — $0.06
- Caffeine: 180mg (effective) — $0.004
- Various prop-up ingredients: 620mg
Total raw ingredient cost: ~$0.20 per serving.
Both formulations have a 7,500mg blend. Both have the same label. One delivers clinical doses. One doesn't. The consumer cannot tell the difference from the label. The brand saves ~$0.20 per serving — across 100,000 units monthly, that's $20,000/month in margin extracted from consumers who thought they were getting a clinical product.
What We Found: 14 Pre-Workouts Tested
We purchased and assayed 14 of the top-selling pre-workouts in the United States, by market share data. For each, we tested:
- Total caffeine vs. label claim (or stated amount)
- L-Citrulline content vs. 6g minimum effective dose (MED)
- Beta-Alanine content vs. 3.2g MED
- Whether the label uses a proprietary blend
Key findings:
Caffeine accuracy: 11 of 14 products were within ±10% of stated caffeine content. This is the one ingredient brands don't underdose — they know consumers feel caffeine immediately, and a miss would generate returns and reviews.
L-Citrulline underdosing: 9 of 14 products contained less than 6g L-Citrulline per serving. Six of those nine contained less than 3g — less than 50% of the minimum effective dose.
Beta-Alanine underdosing: 12 of 14 products contained less than 3.2g beta-alanine per serving. The median was 1.4g — 44% of the clinical threshold. The tingling you may feel (paraesthesia) begins at approximately 800mg, so brands dose enough to cause a sensation but not enough to produce the actual ergogenic effect (reduced muscle acidosis, which requires 3.2g+/day).
Full label transparency: 3 of 14 products disclosed all individual ingredient amounts. Those three were: Legion Pulse, Transparent Labs BULK, and Bare Performance Project 1.
The prop-blend offenders
We won't name all 14 products here, but the pattern was clear: every product using a proprietary blend was underdosed on at least one performance-relevant ingredient. The brands without proprietary blends were correctly dosed on all three markers.
This is not a coincidence. Prop blends exist specifically to enable this.
The Cost Calculation
| Tier | Example | Cost/serving | L-Cit | Beta-A |
|---|---|---|---|---|
| Transparent, clinical | Legion Pulse | $2.20 | 8g ✓ | 3.6g ✓ |
| Prop blend, mass market | [Unnamed] | $1.40 | ~2g ✗ | ~1.4g ✗ |
| Prop blend, budget | [Unnamed] | $0.90 | ~1.5g ✗ | ~0.8g ✗ |
The "savings" on cheaper prop-blend products are largely illusory. You're paying less for a product that doesn't work as advertised. The $0.80/serving premium for a fully-dosed transparent product is paying for the actual ingredients — not the label.
What to Do
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Avoid proprietary blends. Any product that lists a blend without individual doses should be presumed to be underdosed until proven otherwise by third-party assay.
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Check for Informed Sport, NSF Sport, or Informed Choice certification. These certifications test for banned substances but do not verify dosing. They are a necessary but not sufficient condition.
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Read the label number by number. L-Citrulline or Citrulline Malate (as L-Citrulline equivalent) should be ≥6g. Beta-Alanine ≥3.2g. Caffeine ≥150mg. If any aren't listed individually, assume underdosing.
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Use our reviews. We assay every pre-workout we review and publish the lab data. You shouldn't have to take our word for it — the numbers are in the report.
Published by Fitlab Research Team, May 2026. Lab assay data available to subscribers.