Thickening Mousse is an aerosol styling mousse from Kenra Professional built to plump the hair shaft itself, adding body from the strand outward rather than relying on stiff-hold polymers alone. It's propelled by isobutane and propane and dispenses as a light foam worked through towel-dried hair.
The formula centers on Polyurethane-14 and an AMP-Acrylates copolymer for flexible hold, paired with a Polyquaternium-4/Hydroxypropyl Starch Copolymer that coats and thickens each strand. Kenra states it increases hair shaft density by up to 150%, resists humidity for up to 48 hours, and protects against heat styling up to 428°F (220°C), drying to a light, flexible hold that brushes out without flaking.