Body & Beauty / Compounds / Betaine

Betaine on your skin: a safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Safety profile for Betaine relevant to people.

What is betaine?

The IUPAC name is 1,1,1-trimethylmethanaminium.

Also known as: 1,1,1-trimethylmethanaminium, trimethylglycine, TMG, betaines.

IUPAC name
1,1,1-trimethylmethanaminium
CAS number
107-43-7
Molecular formula
C5H11NO2
Molecular weight
117.15 g/mol
SMILES
C[N+](C)(C)CC(=O)[O-]
PubChem CID
247

Risk for people

Low risk

Regulatory consensus

3 regulatory and scientific bodies have classified Betaine. The classifications differ — that's the data.

AgencyYearClassificationNotes
EU_CLP—Not ClassifiedBelow hazard classification thresholds
INCI——Approved cosmetic ingredient; INCI Name: BETAINE
FDA——GRAS status for food applications

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter betaine

  • skincare products
  • haircare products
  • dietary supplements
  • cosmetic formulations

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Betaine:

  • Glycerin (plant-derived) — gold standard humectant, excellent safety profile
    Trade-offs: Consumer preference for 'natural' label; many natural fragrance compounds are potent allergens (limonene, linalool, eugenol); 'natural' ≠ 'safe'; often more expensive than synthetic equivalents.
    Relative cost: 2-5× conventional
  • Hyaluronic acid — naturally occurring, very low sensitization potential
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 2-5× conventional
  • Panthenol (provitamin B5) — well-tolerated, additional skin-soothing properties
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain betaine?

Betaine appears in: skincare products; haircare products; dietary supplements.

Why do regulators disagree about betaine?

Betaine has been classified by 3 agencies including EU_CLP, INCI, FDA, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Betaine in the body app

Look up products containing betaine, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (2)
  1. PubChem Compound CID 247 — database
  2. ATSDR Toxicological Profile — CAS 107-43-7 — reference

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →