Hedrin Treat & Go Head Lice Spray 60ml. Hedrin treat and go lotion, spray and mousse all contain activdiol, a substance that works by stripping away the waxy cuticle (outer skin) of head lice, causing them to dehydrate and die.. Hedrin Treat & Go contains 5% Activdiol.. Head lice cannot become resistant to Hedrin treat and go because it works in this physical way, unlike conventional insecticides for head lice which poison the parasites by chemical means.. Hedrin treat and go kills both lice and eggs. However, treatment should be repeated after seven days to kill any lice that survived or have hatched from eggs that survived the first application.