Cysteine
Cysteine carries a source-backed screening score of 5/5 and appears in 17 indexed US food products. CSPI rates it “Safe.”
Source-backed answer
Cysteine appears in 17 catalogued products. CSPI rates it “Safe.” No FDA SAFFA status is attached. Those source labels describe the ingredient; they do not establish whether a particular product, dose, allergy, or diet is safe.
- 17
- catalogued products
- #10,499
- usage rank of 247,206
- 11
- named brands represented
- 62%
- 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 Cysteine - usage rank #10,499
- Usage rank
- #10,499
- of 247,206 ingredients that appear in at least one catalogued product, tied with 444 others that also appear in exactly 17 products.
- Typical depth in an ingredient list
- 62%
- Mean relative depth 62% across 17 parsed labels, slot 22.2 on average. Cysteine tends to sit in the lower half of the list. Depth is location on the label, not a measured dose.
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.
Reading this ingredient record
Separate this ingredient from its product neighborhood
This is a mixed product neighborhood: 8 of 17 records have some flagged component, while the rest do not. Compare Apple Caramel Cake Mix; Asiago Turkey; Beigne to see how surrounding formulations change; do not assign their 55–100 score range to Cysteine itself. The ingredient most often sits in the lower half of the list, and Plant-based foods and beverages supplies the most useful like-for-like starting point for a label review.
8 of 17 linked records have some flagged component
All 17 NOVA-classified records cluster most heavily in Group 4, while the first-category labels split across several shelves. That makes the 55–100 score spread more informative than the average alone: investigate the low end, identify the actual flagged row, and compare it with a similar unflagged formulation before drawing a conclusion.
Next check: pair one flagged product with a similar unflagged product from the same shelf category.
Function
Preservative
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 Cysteine
Products Containing Cysteine
16 busy labels from the 17 indexed products that list Cysteine:
High-volume peers for Cysteine
Cysteine sits among other busy catalog rows (17 products, mean score 87.6/100). Count peers and score peers are listed separately on purpose.
Similar mean product score
Mean product-score neighbours (≥50 scored products), kept separate from the product-count peers above.
Using the Cysteine evidence
Use the 17-product footprint and source labels as a starting point, then inspect the records most relevant to your question.
- Open the product sample for Cysteine and read how the term sits on real packages. Browse linked labels
- Compare another ingredient’s source-backed rating, FDA status, and product footprint. Compare a peer
- Read how PlainFoodSafe joins source records before treating a screening label as a personal food or health conclusion. See source joins
This page describes published source classifications and product-label coverage. It is not dietary, allergy, or medical advice.
Cysteine — common follow-ups
Does Cysteine carry its own safety label in this catalog? ▼
This is a mixed neighborhood: some linked products carry a separate flag while others do not. Cysteine itself carries a CSPI "Safe" rating where the source record supplies them. Compare like-for-like products before treating the average screening score as an ingredient verdict.
Which product shelves show up most often with Cysteine? ▼
Cysteine ranks in the top decile by product count (#10,499 of 247,206), appearing in 17 indexed products led by Plant-based foods and beverages. The sample list below is a slice of that footprint, not the full universe.
What does Cysteine do in food? ▼
Cysteine is recorded as a preservative in source technical-effect fields.
Regulatory status: FDA SAFFA (Cysteine). 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.