L-leucine
L-leucine carries a source-backed screening score of 3/5 and appears in 270 indexed US food products.
Source-backed answer
L-leucine appears in 270 catalogued products. CSPI has no rating attached in this snapshot. Its FDA SAFFA status is “Approved.” Those source labels describe the ingredient; they do not establish whether a particular product, dose, allergy, or diet is safe.
- 270
- catalogued products
- #1,593
- usage rank of 247,206
- 92
- named brands represented
- 34%
- average depth down ingredient lists
Catalog prevalence comes from Open Food Facts ingredient lists. FDA SAFFA and CSPI Chemical Cuisine labels are shown only when the source record contains them.
High-volume listing for L-leucine - usage rank #1,593
- Usage rank
- #1,593
- of 247,206 ingredients that appear in at least one catalogued product, tied with 1 other that also appear in exactly 270 products, listed in more products than 99.4% of them.
- Typical depth in an ingredient list
- 34%
- Averaged label depth puts L-leucine in the upper half of the list (34% of list length, mean slot 9.9). Compound ingredients and OCR noise mean this cannot stand in for quantity.
Ranks use Open Food Facts ingredient rows on this site’s refresh cycle. 247,206 ingredients with ≥1 product appearance enter the ranking. Prevalence and list depth are catalog facts, not toxicology.
What this page can and cannot answer
Audit the co-occurring flags first
59.3% of the linked products contain at least one separately flagged ingredient, making co-occurrence the dominant follow-up question. That figure does not identify L-leucine as the trigger. Open records such as 100% Mass Gainer Chocolate Fudge Brownie; 100% Pure Whey With Grass Fed Whey Isolates Vanilla Cream Slice Flavour; 3rd Trimester Prenatal Pack and inspect which ingredient row carries the caution marker. The 85.7/100 product average is therefore a triage signal for this surrounding formulation set, not an ingredient verdict. Its 34% average label depth helps locate the term when checking the package.
59.3% of linked products contain a separately flagged ingredient
Processing is unusually concentrated here: Group 4 accounts for 269 of 269 NOVA-tagged records. That describes the surrounding products, not the substance. For a useful comparison, hold category and processing level constant, then inspect which named component changes alongside the caution flag; otherwise the product mix will confound the ingredient question.
Next check: open the lowest-scoring linked formulation and locate the exact caution-marked component.
What else is usually in the same product as L-leucine
Across the 270 products on this site that list L-leucine, these flagged additives appear alongside it most often. The comparison column is how often each one appears across every product with a parsed ingredient list, so the two figures are measured over the same set. Sucralose shows up about 21.4x more often with L-leucine than in the catalogue at large.
| Additive | Shared products | Share of L-leucine products | Share of all products |
|---|---|---|---|
| Sucralose | 156 | 57.8% | 2.7% |
| Acesulfame Potassium | 93 | 34.4% | 1.8% |
| Carrageenan | 12 | 4.4% | 4.5% |
| Monk fruit extract | 9 | 3.3% | 0.5% |
Co-occurrence describes what manufacturers formulate together. It is not a claim that these additives interact, and it carries no regulatory meaning. Counted over products with parsed ingredient lists; Open Food Facts, 2026-09-01.
Function
FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, NUTRIENT SUPPLEMENT
How do the sampled products compare?
Each point is one of the 16 sampled products listed below: its overall safety score against how many separately flagged ingredients its label carries. Bubble size is the number of ingredient rows the label actually resolved to.
Safety score vs. flagged-ingredient count for products containing L-leucine
Products Containing L-leucine
A sample of 16 high-volume listings among the 270 indexed products containing L-leucine:
Peer ingredients with comparable catalog mass (near “Carbohydrate Gum”)
Top-decile company for L-leucine: 270 listings averaging 85.7/100. Comparable product-count neighbours: Carbohydrate Gum · Celery Juice Concentrate · Enrichment.
Similar product count
Nearest other ingredients by Open Food Facts product count (floored at ≥50).
Similar mean product score
Nearest other ingredients by mean product screening score (floored at ≥50 scored products), distinct from the count row.
What to do with this L-leucine record
270 product rows plus any FDA/CSPI fields on L-leucine are the evidence base — drill into the listings that matter for your decision.
- Review the sampled product records that list L-leucine to see how the ingredient appears in actual labels. Open product sample
- Place L-leucine next to “Celery Juice Concentrate” (or another peer) using the same FDA/CSPI and prevalence fields. Compare a peer
- See the join rules behind screening scores before reading them as dietary advice. Read the methodology
This page describes published source classifications and product-label coverage. It is not dietary, allergy, or medical advice.
Frequently Asked Questions
How should I read safety signals when L-leucine sits in heavily flagged products? ▼
59.3% of linked products contain at least one separately flagged ingredient, so the first task is locating which row carries the caution marker — not assuming L-leucine is the trigger. Where a source rating exists, L-leucine scores 3/5 on this site's screening scale with FDA SAFFA status "Approved". None of that replaces a product-, dose-, allergy-, or person-specific determination.
Which product shelves show up most often with L-leucine? ▼
L-leucine ranks in the top decile by product count (#1,593 of 247,206), appearing in 270 indexed products led by Dietary supplements. The sample list below is a slice of that footprint, not the full universe.
What function does L-leucine serve when it appears beside other flagged additives? ▼
L-leucine is recorded as a flavor enhancer, flavoring agent or adjuvant, nutrient supplement in source technical-effect fields. In high co-flag products, that function coexists with other caution-marked components — inspect the full list rather than isolating this role.
Regulatory status: FDA SAFFA (L-leucine). Safety ratings: CSPI Chemical Cuisine; product presence: Open Food Facts via PlainFoodSafe (September 2026). Figures are computed from those sources, no editor-typed counts. Methodology · State regulations.