Discover our 2 simple steps for stronger, healthier hair and nails – built on our breakthrough Biodiffusion™ bond repair technology for multi-layered repair. 1. Repair hair with epres™ Bond Repair Treatment. One-step spray actively repairs broken disulfide bonds to restore hair's structure in just 10 minutes.2. Repair nails with ePhD™ Bond Repair Nail Treatment. Penetrates the tightly cross-linked bonds in the nail to deliver immediate repair and lasting restoration over time.