Home / Field guides / Clinical Doses: What the Research Actually Used
Field guide
Every ingredient on a supplement label is a dose decision, and most labels don't tell you what that decision was measured against. Below are the thresholds we use, drawn directly from the studies that established them, along with what the research actually looked like and why "more" isn't automatically "better."
| Ingredient | Clinical dose | Source |
|---|---|---|
| L-Citrulline | 6,000 mg | Bailey et al., J Appl Physiol 2015 |
| Citrulline Malate 2:1 | 8,000 mg | Perez-Guisado & Jakeman, J Strength Cond Res 2010 |
| Beta-Alanine | 3,200 mg | Trexler et al., ISSN Position Stand 2015 |
| Creatine Monohydrate | 5,000 mg | Kreider et al., ISSN Position Stand 2017 |
| Betaine Anhydrous | 2,500 mg | Cholewa et al., J Int Soc Sports Nutr 2013 |
| Caffeine | 200 mg | Guest et al., ISSN Position Stand 2021 |
| L-Tyrosine | 1,000 mg | Jongkees et al., J Psychiatr Res 2015 |
| Taurine | 1,000 mg | Waldron et al., Sports Med 2018 |
| Alpha-GPC | 300 mg | Ziegenfuss et al., J Int Soc Sports Nutr 2008 |
| L-Theanine | 100 mg | Giesbrecht et al., Nutr Neurosci 2010 |
These are the numbers we score against. Not a marketing claim, not a round number that sounds sufficient — the dose that was actually administered in the study behind each ingredient's use case.
This is the single most common source of confusion on a pre-workout label, and it's worth being precise about it.
L-citrulline is the free amino acid on its own. Citrulline malate is L-citrulline bound to malate, typically in a 2:1 ratio, meaning a given weight of citrulline malate contains meaningfully less actual citrulline than the same weight of pure L-citrulline — the malate portion adds mass without adding citrulline.
Bailey et al. (2015) studied 6 g of L-citrulline. Perez-Guisado & Jakeman (2010) studied 8 g of citrulline malate. Those are different compounds studied at different total weights, and treating "8 g citrulline malate" as equivalent to or better than "6 g L-citrulline" misreads the label. A product listing "citrulline malate 8,000 mg" is not delivering 8 g of citrulline — depending on the exact ratio used, the actual citrulline content is lower, closer to 5–6 g minus the malate weight — and it isn't automatically equivalent to a product listing "L-citrulline 6,000 mg," which delivers a full 6 g of the amino acid itself.
This is why the two are tracked as separate line items rather than folded into one "citrulline" bucket. Conflating them would mean crediting a product for a dose it didn't actually deliver, which defeats the purpose of dose auditing in the first place.
It's intuitive to assume that if 3,200 mg of beta-alanine is the studied maintenance dose, then 6,000 mg must work even better. That intuition doesn't hold up, and it isn't how we score.
The clinical dose is the amount used in the research that established an effect — it's a floor that needs to be met for a product to plausibly deliver what the ingredient is known for, not a point on a dose-response curve where more is proportionally better. Ingredients have different behaviors above their studied range: some show no meaningful additional effect once you're past the dose that produced the measured outcome, some come with dose-dependent side effects that were outside the scope of the original studies, and in every case, going past the studied dose means you're now outside the data the "clinical dose" label was borrowing credibility from. A product that doses far above the threshold hasn't demonstrated it's more effective — it has demonstrated it's outside the range anyone actually measured.
Practically, this also means a giant dose isn't a substitute for an honest label. A product could bury an ingredient at 20,000 mg specifically to make the "clinically dosed" claim viscerally impressive while the total serving becomes unpalatable, expensive, or oddly proportioned relative to everything else in the formula. Meeting the threshold is the bar. It isn't a race past it.
The useful exercise is narrow: find the ingredient, find its disclosed dose, and compare it against the number the research actually used — not a rounder number, not a related-sounding compound, not an assumption based on where it sits in the ingredient list. Where a dose isn't disclosed at all, because it sits inside a proprietary blend, there's no way to run this comparison, which is exactly why blends carry their own separate scrutiny.
This isn't dosing advice — what to take, and how much, is a decision between a reader and whoever they get personal guidance from. It's a description of what a specific set of studies used, so a label claim can be checked against something real.
The sources above aren't an arbitrary pick from the literature. Several are ISSN (International Society of Sports Nutrition) Position Stands — consensus documents where a panel of researchers reviews the available trials on an ingredient and states where the evidence actually supports a specific effect at a specific dose. Where a single trial is cited instead of a position stand, it's because that trial established the dose most commonly referenced by later research on the same ingredient. None of this makes the number permanent — sports nutrition research continues, and a threshold can move if better evidence arrives — but it does mean each figure traces back to a published, citable source rather than to convention or round numbers that simply sound sufficient.
Caffeine is the one ingredient on this list most often dosed by body weight in the underlying research rather than as a single fixed number — Guest et al. describe an effective range around 3–6 mg per kilogram of body weight, with 200 mg used here as the floor at which an ergogenic effect has been observed across a general adult population. A product listing well below that floor is dosing under the range the position stand describes; a product dosing well above it has moved into territory where individual tolerance, sleep disruption, and cardiovascular response start to matter more than any single study can generalize.