Thermal protectors, usually heat-absorbing polymers, shielding the hair against excessive heat, caused by, e.g., blow-drying or curling irons or hot rollers.
Glossers, light-reflecting chemicals which bind to the hair surface. Usually polymers, usually silicones, e.g., dimethicone or cyclomethicone.
Oils (EFAs – essential fatty acids), which can help dry/porous hair become more soft and pliable. The scalp produces a natural oil called sebum. EFAs are the closest thing to natural sebum (sebum contains EFAs).
Surfactants – Hair consists of approximately 97% of a protein called keratin. The surface of keratin contains negatively-charged amino acids. Hair conditioners therefore usually contain cationic surfactants, which don’t wash out completely, because their hydrophilic ends strongly bind to keratin. The hydrophobic ends of the surfactant molecules then act as the new hair surface.
Lubricants, such as fatty alcohols, panthenol, dimethicone, etc
Sequestrants, for better function in hard water.
Antistatic agents
Preservatives