- A revolutionary shampoo that lets you wash your way to beautiful, healthy looking hair. Powered by our patented Healthy Hair Molecule (OFPMA), Perfect hair Day (PhD) Shampoo is the first step to: helping you wash your hair less often; making hair look healthier instantly and improves over time. Perfect hair Day (PhD) Shampoo is ideal for all hair types. It is sulfate-free and silicone-free. Safe formulated for color and chemically treated hair. Apply PhD Shampoo to wet hair. Massage into a rich lather. Rinse. Follow with PhD Conditioner.