Encyclopedia · silicone
Amodimethicone
A dimethicone with positively charged amine groups, so it clings to damaged hair and resists rinsing better than plain dimethicone.
What it is
An amino-substituted silicone polymer used in conditioners and leave-ins. The Cosmetic Ingredient Review panel reviewed it together with dimethicone and related polymers. Nair 2003
How it works
Damaged hair carries more negative charge, and electrostatic attraction is the main deposition force on bleached hair. Labarre 2023 That fits the rationale for amine groups with a positive charge (an inference; the paper tested a silicone conditioner, not amodimethicone specifically).
What the studies show
- A Kao shampoo and conditioner system with amino-silicone formed a fine surface structure that increased colour intensity and shine, including on dyed hair. Watanabe 2007
- Electrostatics dominated deposition on bleached hair in a force-microscopy study. Labarre 2023
- All of these data are industry or instrumental. We found no human trials.
How it's used in studies
Rinse-off conditioners. Typical product percentages were not verified.
Side effects and safety
The Cosmetic Ingredient Review panel judged it safe as used. Nair 2003 It is a cosmetic ingredient and can still build up with repeated use.
Bottom line
Often the most useful silicone for bleached, coloured or heat-damaged hair, though the solid evidence is thinner than the marketing suggests. We are only moderately sure of its benefit. See silicones.
Studies 3
Nair B, Cosmetic Ingredient Review Expert Panel. Final report on the safety assessment of stearoxy dimethicone, dimethicone, methicone, amino bispropyl dimethicone, aminopropyl dimethicone, amodimethicone, and related silicones. Int J Toxicol. 2003
Result: The panel judged dimethicone and the amino-silicones safe as used in cosmetics, with minimal absorption.
Read the study ↗Watanabe S et al. Formation of nanostructure on hair surface. J Cosmet Sci. 2007
Tested: shampoo and conditioner system with amino-silicone
Result: A very fine surface structure formed on the hair, raising colour intensity and shine and helping dyed hair keep its look.
Read the study ↗Labarre L et al. Hair surface interactions against different chemical functional groups as a function of environment and hair condition. Int J Cosmet Sci. 2023
Result: Hydrophobic interaction drove deposition on virgin hair and electrostatic interaction on bleached hair.
Read the study ↗Related
- DimethiconeThe standard hair silicone, a water-insoluble oil that coats the fibre for slip, shine and friction control without repairing anything.
- Bis-aminopropyl dimethiconeAn amino-terminated silicone related to amodimethicone, used in conditioners and colour-care products to stick to damaged hair.
- DimethiconolA dimethicone with hydroxyl end groups, usually supplied as a thick gum emulsion for longer-lasting slip in rinse-off conditioners.
- Silicones in hair careSilicones coat hair to cut friction and add shine without repairing it; buildup is real but manageable, and the scare claims are unsupported.