Indigotine (Blue 2)

Also known as: FD&C Blue No. 2, Blue 2, indigo carmine, E132

Lower concernunder our published method

By NordicScan Evidence Engine · generated from structured evidence records · source spans verified by automated gates · Reviewed 2026-07-08 · Evidence snapshot geo-wave1-evidence-snapshot-2026-07-08 · Scoring engine det_v3 · how we score.

What it is

Indigotine is a synthetic blue colour additive used in some processed foods and dietary supplements.

Why people ask

People ask because the same dye can appear as Blue 2, FD&C Blue No. 2, indigotine, indigo carmine, or E132.

What our method flags — by use

Food · US federal

In US food, our method currently rates Blue 2 as lower-concern because the source cell is a listing and certification cell.

The US listed by 21 CFR 74.102 FD&C Blue No. 2 for coloring foods, including dietary supplements, generally in amounts consistent with current good manufacturing practice and certification requirements.

Authority / source	Finding (our paraphrase)	Evidence tier	Date	Link
eCFR / US FDA	The US listed by 21 CFR 74.102 FD&C Blue No. 2 for coloring foods, including dietary supplements, generally in amounts consistent with current good manufacturing practice and certification requirements.	authority_regulatory	2026-07-02	source

Evidence coverage for this use: Limited (computed from source count × authority tier × recency; signals depth, does not change the concern band).

How this moves a product’s score

On a product score, Blue 2 contributes little to no concern signal in this snapshot unless another product-specific rule applies.

Nordic Scan provides ingredient information and a concern score under our published method, for general consumer research. It is not medical advice and not a medical device, and does not diagnose, treat, cure, or prevent any disease, or determine the safety of any product. Decide for yourself.

This is what Indigotine (Blue 2) is. What’s in the products you buy? Scan a label and see the concern signals our method flags. Get the app.

Reviewed 2026-07-08 · Evidence snapshot geo-wave1-evidence-snapshot-2026-07-08 · Scoring engine det_v3 · Sources checked 2026-07-08 · See how we score.