THICK.AGAIN is a treatment must-have if you'd like your hair to be thicker, lusher and more full of life. This leave-in treatment is a thickening treatment which has been formulated for men with fine or thinning hair which needs a boost. The ingredients have been carefully selected and blended to provide a thickening product which helps thicken hair, prevent breakage and feel fuller with a breakthrough technology gleaned from the technology behind eyelash thickening and lengthening treatments.