Achieve a smooth, polished finish with REF Stockholm’s Hair Serum — a lightweight, concentrated formula that seals the cuticle, tames frizz and delivers instant shine. The nourishing blend strengthens the hair fibre, leaving it soft, supple and luminous without weighing it down. Enhance the result with favourites from our Leave In collection — try Hair Oil, a Leave-In Conditioner or a conditioning spray — to seal in moisture and gloss.