Medik8 Hydro B5 Liquid Rehydration Serum. Travel Size 10ml. Brand new and sealed. Infuse your skin with intense hydration and long-lasting moisture with Hydr8 B5, Medik8's best-selling moisturising serum. KEY BENEFITS A deeply hydrating, crystal-clear serum that sinks in quickly to flood the skin with moisture. RESULTS Softens fine lines and wrinkles to leave skin supple, restored and nourished.