Believe It: How to Go from Underestimated to Unstoppable is an inspiring personal and business memoir by Jamie Kern Lima, the founder of IT Cosmetics. In this powerful book, she shares her journey from being repeatedly rejected and underestimated to building a billion-dollar beauty company.

Through honest storytelling, Jamie reveals the challenges she faced — including self-doubt, rejection from investors, and the pressure of pursuing a dream that many people believed would fail. She explains how learning to trust her instincts, believe in her purpose, and stay resilient helped her turn obstacles into opportunities.

The book offers motivational lessons about confidence, perseverance, entrepreneurship, and personal growth. It encourages readers to trust their inner voice, overcome fear, and believe that their ideas and dreams are worth pursuing.