An allergen scanner that catches what other apps miss

SYE scans barcodes and restaurant menus for over 100 allergens, including the derivative ingredient names that confuse most other scanners. Free on iOS. Built for celiac, peanut allergy, dairy intolerance, soy, eggs, and dozens of conditions where one wrong ingredient ruins your day.

Why allergen scanners miss things

Most food scanners catch obvious labels. If a product says "wheat" or "milk" on the front, every scanner flags it. The problem starts with derivatives — ingredients that contain an allergen but use a different name on the label.

• "Casein" and "whey" are dairy. A lactose-intolerant user scanning a "non-dairy" creamer with sodium caseinate gets a green light from most apps. SYE doesn't.
• "Modified food starch" in a US product can be derived from wheat. EU labels disclose the source; US labels often don't. SYE flags it as a possible gluten source.
• "Carmine", "natural red 4", and "cochineal" are all the same insect-derived dye. Vegans avoiding it have to know all three names. SYE covers them.
• "Tocopherols" and "lecithin" can be soy-derived. SYE prompts when the source is ambiguous.

The full database is published in our 100+ allergen derivatives reference. Every match runs locally on your phone the moment you scan — no waiting on a server.

What SYE does that no other scanner does

1. Restaurant menu allergen detection

Photograph any restaurant menu. SYE's vision AI extracts each dish, infers likely ingredients from typical preparation, and flags items containing your configured allergens. This feature is unique to SYE — no other mainstream scanner offers menu detection. The full workflow is in our celiac restaurant survival guide.

2. 100+ allergens with derivative matching

Yuka and similar apps catch headline allergens (gluten, lactose, nuts) when explicitly labeled. SYE catches the same allergens plus their less-obvious chemical names: lactalbumin, sodium caseinate, modified food starch, hydrolyzed wheat protein, and dozens more. See our EU vs US allergen labeling comparison to understand why this matters.

3. Family profiles, separate for each member

One app, multiple profiles. Set up the parent's profile, the kid's allergy list, the partner's diet — each profile gets its own personalized verdict on every scan. Synced via private iCloud, no central server. Read more in our family profiles guide.

4. Personalized scoring on top

Beyond allergens, SYE scores every product against your full profile (age, BMI, conditions, diet preferences). The same Nutella jar produces a different verdict for a 25-year-old triathlete vs a type 2 diabetic — covered in our Yuka vs SYE comparison.

The allergens SYE covers

Every EU Regulation 1169/2011 declared allergen, plus the FDA-recognized US allergens, plus dozens of derivatives:

• Gluten / wheat — including spelt, kamut, einkorn, modified food starch (when wheat-derived), hydrolyzed vegetable protein, malt, brewer's yeast
• Dairy / lactose — milk, cream, butter, casein, caseinate, whey, lactalbumin, lactoglobulin, ghee, ghi
• Tree nuts — almonds, hazelnuts, walnuts, cashews, pistachios, pecans, brazil nuts, macadamia, pine nuts
• Peanuts — peanut, groundnut, arachis oil (rare unrefined forms)
• Eggs — albumin, lysozyme, lecithin (when egg-derived), globulin
• Soy — soybean, tofu, edamame, tempeh, miso, tamari, lecithin (when soy-derived), tocopherols (when soy-derived)
• Sesame — sesame, tahini, gomashio (newly added to FDA disclosure list in 2023)
• Fish — all finned fish + derivatives (fish sauce, anchovy paste, surimi)
• Shellfish / crustaceans — shrimp, prawn, crab, lobster, crawfish, mollusks
• Mustard, celery, lupin, sulfites, mollusks — EU-specific declared allergens
• Vegan-relevant — gelatin, isinglass, carmine, shellac, lanolin (cosmetics-adjacent)

How to set up allergen alerts

1. Open SYE → Profile → Allergens
2. Toggle each relevant allergen. For each, you can set severity (mild / severe / anaphylaxis-risk)
3. Severe and anaphylaxis-risk allergens trigger a full-screen DANGER warning when detected, not a small badge — designed so a kitchen-distracted parent can't miss it
4. Optional: add custom ingredients you personally avoid (for non-allergy intolerances or religious restrictions)

Frequently asked questions

How many allergens does SYE detect?

Over 100, including all 14 EU regulated allergens, the 9 FDA-recognized US allergens (sesame added 2023), and 80+ common derivative ingredient names. Full reference at the allergen derivatives article.

Is SYE safe to rely on for life-threatening allergies?

SYE is a decision-support tool. It catches allergens declared in ingredient lists, and it has a strong derivative-name database. It cannot detect cross-contamination from shared kitchen equipment, fryers, surfaces, or airborne residue. For severe or anaphylaxis-risk allergies, always confirm with the restaurant or manufacturer. SYE makes the conversation easier — it does not replace it.

Does it work on restaurant menus?

Yes — this is one of SYE's unique features. Photograph a printed or digital menu, the AI extracts each dish, and items containing your allergens are flagged based on typical preparation. The celiac restaurant guide walks through the workflow.

What's the cost?

Free tier: 3 personalized scans per day with full allergen detection. Premium ($2.99/month): unlimited scans + Aisle Scan + Quick Compare. No ads on either tier. No account required.

Is SYE on Android?

iOS only as of 2026. Android is on the roadmap with no firm date. If you have severe allergies and need an Android option today, Find Me Gluten Free has a different angle (restaurant directory, not ingredient scanner) that may help.