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Metformin

CAS 657-24-9 · 100/100 · High conf.

Metformin chemical structure

Concern score

100/100Critical concern based on regulatory listings.
High confidence

Metformin in plain language

What it is

Also known as Metformin (INN) and its salts · 3-(diaminomethylidene)-1,1-dimethylguanidine · Metformin extended release · N,N-Dimethyltriimidodicarbonic diamide · 1,1-Dimethylbiguanide · Biguanide, 1,1-dimethyl-

Show all 25 names

Cidophage · Diaformin · Dimethylbiguanid · Dimethylbiguanide · Dimethylguanylguanidine · Emiphage · Ficonax · Fluamine · Imidodicarbonimidic diamide, N,N-dimethyl- · LA-6023 · Meguan · Metformina · Metformine · Metiguanide · N,N-Dimethylbiguanide · N,N-Dimethyldiguanide · N,N-dimethylimidodicarbonimidic diamide · N1,N1-Dimethylbiguanide · Novo-Metformin

What it does

We don't have a plain-language description for Metformin yet.

Recorded functional uses: Pharmaceutical

Is it a concern?
Critical concern: no hazard classifications on record. It is banned in EU cosmetics.

Why it's flagged

Metformin (INN) and its salts is prohibited in cosmetic products under Annex II of the EU Cosmetics Regulation (EC) 1223/2009.

RestrictedEU EC — banned

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

Restrictions first, then routine listings from published regulatory sources.

  • EU Annex II — prohibited
  • EU prohibited in cosmetics

Recorded in these product areas

  • Found in consumer products
  • Industrial
  • EUEC

    Annex II of EU Cosmetics Regulation (EC) 1223/2009: substances prohibited in cosmetic products.

    banned
    View source →
  • EUCosIngActiveCosmetics Regulation annex II / ref 147.
    • Cosmetics Regulation annex II / ref 147.Source →
  • USEPAcommercial use observedEPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Pharmaceutical.
    • EPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Pharmaceutical.Source →
  • USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
    • openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for Metformin. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

  • SCCS

    EU Scientific Committee on Consumer Safety

    No SCCS opinion on file.

  • CIR

    Cosmetic Ingredient Review (US expert panel)

    No CIR safety assessment on file.

Evidence & sources

No graded research studies for Metformin yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

7 data sources

Where this comes from

  • CosIng

    regulatory · updated 2026-09-23

    Open →
  • EU CosIng Cosmetics Regulation Annexes

    regulatory · updated 2010-10-20

    Open →
  • EPA Chemical and Products Database

    exposure · updated November 2007

    Open →
  • EPA DSSTox Identifiers

    chemistry · updated 2025-12-29

    Open →
  • FDA GSRS UNII

    registry · updated 2026-02-26

    Open →
  • openFDA Substance

    registry · updated 2026-05-24

    Open →
  • PubChem Live Enrichment

    chemistry · updated 2026-05-17

    Open →
Reference links (1)
Openfda substance

dailymed.nlm.nih.gov

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Fragrance avoidance

No fragrance-linked caution surfaced in the current profile.

Good fit

This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.

Where it has been recorded

How often EPA CPDat has listed Metformin in a product composition. These are source records, not Greenveil catalog products.

Named organisations

6

Typical roles

Pharmaceutical
See products using Metformin →