THICK BOOST SHAMPOO 16.0FLOZ. Benefits: Hawthorne Thick Boost Shampoo powers up your hair with Biotin and Rosemary Extract, natural DHT blockers that help strengthen every strand and boost volume. Perfect for fine or thinning hair, this formula leaves your hair feeling thicker, stronger, and healthier - without weighing it down.. Key Ingredients: Biotin and Rosemary Extract. Scent Type: Scented with Hawthorne 'Steamroom' cologne, featuring invigorating Eucalyptus Vapor and crisp Shiso Mint, it's as refreshing as it is effective..