- BioSilk Silk Therapy Original is weightless leave-in silk replenishing and reconstructing treatment that helps repair, smooth and protect all hair types. • Fills voids in cuticle to create smooth hair. • Aids in preventing split ends. • Provides incredible shine. Shake well before use. Place a small amount of silk therapy in the palms and apply from the scalp to ends. May be used on wet or dry hair or skin. Us as often as necessary.