Katharyn Holmberg builds Sinful Co. after three years of planning

Katharyn Holmberg, founder and CEO of Sinful Co., launched the Broomfield-based e-commerce intimate apparel company in January 2026 after about three years of planning. Her story centers on startup grit, product development and a push to create better-fitting bra and underwear options.

Why it matters: - Sinful Co. is entering a crowded intimate apparel market with a founder-led brand built around fit, design and a more thoughtful customer experience. - Holmberg’s path shows how first-time founders can turn a long-developing idea into a business through persistence, skills-building and execution. - The company launch also reflects a broader trend in e-commerce: founders using direct-to-consumer channels to challenge established retail categories.

What happened: - Katharyn Holmberg is the founder and CEO of Sinful Co., an e-commerce company in the bra and underwear retail sector based in Broomfield, Colorado. - Sinful Co. launched in January 2026 after about three years of planning and development. - Holmberg built the company from the ground up while handling product development, manufacturing coordination, marketing, advertising and operations. - The idea for Sinful Co. emerged during a late-night conversation with a childhood friend about frustration with poorly fitting and unappealing intimate apparel.

The details: - Holmberg spent about three years preparing before formally starting the business. - She worked through business permits, product pattern development, manufacturer searches and prototype development. - Holmberg started the company without prior experience running a business, which made marketing and advertising especially difficult. - Her background includes food service and culinary training, plus work as a server and bartender. - Holmberg is completing an Entrepreneurship Certification at Front Range Community College. - Her stated values are kindness, authenticity and honesty. - Holmberg’s career advice came from another entrepreneur who urged her to have 100% confidence, aim high and remember that nothing is impossible.

Between the lines: - Holmberg’s story is less about a fast launch than a prolonged build, which can matter in consumer brands where product development and supplier relationships take time. - The emphasis on confidence, persistence and learning suggests Sinful Co. is still in an early stage where founder resilience is part of the brand narrative. - Her focus on better-fitting intimate apparel points to a market opportunity driven by dissatisfaction with existing options, not just a desire to add another label.

What's next: - Holmberg is continuing to develop Sinful Co. while working through the demands of marketing, manufacturing and product refinement. - She is expected to keep building the business step by step as she gains more experience in entrepreneurship. - More information is available through her Influential Women profile.

The bottom line: - Katharyn Holmberg turned a conversation into a startup, and Sinful Co. now serves as a case study in patience, persistence and first-time founder execution.