What Is Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer?
Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer is a silicone-based ingredient designed for hair care. It belongs to the family of amine functional silicones, meaning the polymer chain carries small amounts of nitrogen that can cling to the negatively charged surface of damaged hair. The backbone is made of siloxane units that are crosslinked with diethyl tartrate, which locks the material into a stable three-dimensional network.
This type of silicone was first explored in the 1990s when cosmetic chemists looked for gentler, longer-lasting conditioning agents than earlier dimethicones. By adding amine groups and crosslinking, they found they could create a lightweight film that stays on the hair cuticle without heavy buildup. Today manufacturers start with a base amodimethicone, react it with glycols to introduce hydroxy and methoxy groups, then use diethyl tartrate to crosslink the chains. The finished product is usually dispersed in water or a light solvent to make it easy to add to shampoos and treatments.
You will most often see Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer in rinse-off and leave-in conditioners, smoothing masks, color-protect shampoos, anti-frizz serums and heat-protect sprays. It can also appear in multi-benefit styling creams or split end treatments whenever formulators want soft feel and humidity control.
Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer’s Cosmetic Benefits/Uses
Its role in a formula is straightforward yet valuable.
As a hair conditioning agent, it forms a thin breathable coating over each strand. This coating smooths raised cuticles, reduces friction during combing, boosts shine, controls static and helps hair feel soft without weighing it down. Because the polymer has a slight positive charge, it is attracted to damaged areas so it conditions where it is needed most and resists rinsing, giving longer-lasting results between washes.
Who Can Use Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer
This silicone works well for most hair types including straight, wavy, curly and coily textures. Oily scalps usually tolerate it because the film it leaves is lightweight and does not trap excess sebum. Dry or damaged hair often benefits the most since the positively charged polymer targets rough areas and helps seal in moisture. Extremely fine hair may need lower concentrations, as too much product can create a flat look.
The ingredient is synthetically produced and contains no animal-derived substances so it is generally considered suitable for both vegans and vegetarians.
Current research has not shown any specific risk to women who are pregnant or breastfeeding when the ingredient is used in rinse-off or leave-in hair products. This is not medical advice and anyone who is pregnant or nursing should check with a healthcare professional before adding new products to a routine just to be safe.
Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer is not known to cause photosensitivity so it will not make hair or scalp more sensitive to the sun. It is also odorless and free of common protein allergens, making it a low-risk choice for people who avoid fragranced or protein-based conditioners.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical application of Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer can vary from person to person. The points below list potential issues, but they are unlikely to be the typical user experience when the ingredient is formulated and used correctly.
- Mild scalp irritation or itching in individuals sensitive to silicones
- Product buildup that may leave hair feeling heavy if used in high amounts or without regular cleansing
- Allergic contact dermatitis, though this is rare given the large molecular size of the polymer
- Eye irritation if the product accidentally drips into the eyes during application or rinsing
- Acne or folliculitis along the hairline in people already prone to pore clogging when heavy styling products are layered repeatedly
If you notice any of these reactions stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5
Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer has a large molecular size that sits on the surface of hair rather than penetrating skin or follicles. Its breathable film is less occlusive than heavier oils or waxes, so it is unlikely to block pores in most users. Build-up can still occur if multiple leave-in products are layered without regular cleansing, which is why the rating is not a perfect zero.
Suitable for acne-prone or breakout-prone individuals in typical rinse-off and light leave-in formulas.
Those who experience repeated scalp or hairline congestion may want to clarify periodically to remove residue and keep pores clear.
Summary
Bis-Hydroxy/Methoxy/Methyl Amodimethicone Crosspolymer is chiefly a hair conditioning silicone that smooths the cuticle, reduces friction, boosts shine, controls static and offers light humidity protection. Its amine groups give a gentle positive charge that directs the polymer to damaged spots while crosslinking keeps the film thin and long lasting.
The ingredient appears in a growing number of shampoos, conditioners, serums and heat protectants but it is still less common than classic dimethicone, so you may need to read labels to spot it.
Overall safety data show a low risk of irritation or pore clogging when used as intended. As with any new cosmetic, perform a small patch test before fully incorporating a product that contains this silicone to make sure it agrees with your individual skin and scalp.