How much leucine is in a Quest bar, and is there a bar with more?
Quest doesn't print a leucine figure, but you can get close from the label. Here's our estimate, and the bars that go higher.
A Quest Protein Bar has about 1.9–2.2 g of leucine by our estimate, from 21 g of milk and whey protein isolate. Yes, some bars have more. Leucent 3.0 has 3.0 g but is in pre-production, so you can't buy it yet. On sale now, EVOBAR lists 3.0–3.3 g, Myprotein Loaded EAA 3.0 g and Pursuit about 3.5 g by the brand's estimate.
How we estimate leucine in a Quest bar
Whey protein isolate is about 10–11% leucine and milk protein about 9–10%. Applied to 21 g of protein, that gives roughly 1.9–2.2 g. It's an estimate, not a lab result, and flavours can vary.
Protein bars with more leucine than Quest
| Bar | Leucine | Protein | Status |
|---|---|---|---|
| Leucent 3.0 | 3.0 g | 21 g | Pre-production, not on sale |
| Pursuit Protein Bar | ~3.5 g (brand estimate) | 26.5 g | On sale, includes collagen |
| EVOBAR (EVO Sports Fuel) | 3.0–3.3 g | 20–23 g | On sale, no collagen |
| Myprotein Loaded EAA Bar | 3.0 g | 15 g | On sale |
| ADDRA Labs Leucine-Boosted | ~2.9–3.2 g (part estimated) | 17–18 g | On sale |
| David Protein Bar | 2.0–2.6 g (estimate) | 28 g | On sale, may overlap with Quest |
| Quest Protein Bar | 1.9–2.2 g (estimate) | 21 g | On sale, for comparison |
The bars at about 3 g all add free leucine. See all 16 bars in our high-leucine protein bar comparison.
Is a Quest bar enough on its own?
It's close, but short of the 2.5–3 g research suggests for one meal, and about 1 g short of the 3 g suggested for lifters over 50. Eating it with another protein source closes the gap. See the leucine threshold for where those numbers come from.
Common questions
How much leucine is in a Quest bar?
We estimate 1.9–2.2 g of leucine in a Quest Protein Bar. Quest doesn't list it, so that comes from the bar's 21 g of milk and whey protein isolate, which carry roughly 9–10.5% leucine.
Is there a protein bar with more leucine than Quest?
Yes. Leucent 3.0 has 3.0 g, but it's in pre-production and not on sale. On sale now, EVOBAR lists 3.0–3.3 g, Myprotein Loaded EAA 3.0 g and ADDRA Labs about 3 g, and Pursuit estimates about 3.5 g for its bar. We estimate David at 2.0–2.6 g.
Is a Quest bar enough to reach the leucine threshold?
It's close, but short of the 2.5–3 g research suggests for one meal, and about 1 g short of the 3 g suggested for lifters over 50. Eating it with another protein source closes the gap.
Leucent makes Leucent 3.0, so we're not neutral. Its figures are our planned formula, and it's in pre-production and not on sale. This page is general nutrition information, not medical advice.