About KYIR

Our Mission 

Welcome to KYIR. 

Dedicated to transforming your hair care experience, KYIR is leading a hair care revolution by offering non-toxic and highly concentrated products that harness the power of natural ingredients. We prioritize clean and sustainable solutions for various hair types while ensuring transparency and cruelty-free practices that deliver results.

KYIR’s mission is to encourage hair health through natural and efficacious solutions without harsh chemicals and additives. Join us in celebrating your beauty and healthy hair journey with our innovative plant-based serum. 

Our Story

The founders of KYIR have decades of extensive beauty industry experience between them, with a particular emphasis on clean beauty. Both struggled with hair loss from different perspectives. William’s issues concerned hormones, heredity and diet and Kelsey’s were a result of excessive damage due to chemical processing, over styling and hair extensions. Both were actively searching for a solution to fix thinning hair and make it look better, feel fuller and grow stronger without harmful ingredients.

What began as a simple journey to find a formula for personal use, utilizing clean ingredients that actually worked, turned into their ethical, sustainable luxury hair care brand KYIR.

Now, after three years of research and development, sourcing ingredients from around the globe, and working with one of the cleanest labs in the country, they have launched FULLER, a powerful and highly performing hair serum. 

A fresh-scented blend of citrus, bergamot, ginger and sandalwood (that’s never sticky or oily), this lightweight, luxe serum is formulated with natural, non-synthetic (and patented) ingredients targeted to aid hair growth, improve scalp health and provide immediate volume and fullness. Cruelty-free, FULLER contains absolutely no harsh sulfates, parabens, silicones, phthalates or other harmful chemicals.  Use it as part of your daily grooming ritual to achieve more confidence and a head of healthier, thicker, more volumized hair.


Our Founders  

William Kirst, Co-founder KYIR

With an extensive 17 year career in the beauty industry,  William has worked with high profile prestigious brands such as Dior, Givenchy, Trish McEvoy and RMS Beauty, as well as a wide variety of other clean beauty brands including ,Vinter’s Daughter, One Love Organics and Eve Lom. 

He spent a decade at Trish McEvoy in sales and product development. He was personally recruited by Rose-Marie Swift, founder of RMS Beauty, where he learned about the clean beauty industry, and was responsible for launching their first virtual education platform during the pandemic.

Currently, William is a highly sought after consultant, also working with Bright Beauty Collective, the largest green beauty agency in the industry. 


Kelsey Fenner, Co-founder KYIR

Kelsey has a career that spans two decades in the beauty business. She spent eight years in the medical esthetics industry accumulating extensive knowledge which encompassed advanced aesthetic treatments and procedures. 

She is extremely conversant about all things involving wellness, including health, fitness, personal care and cosmetics. Kelsey is an ardent advocate of not only clean beauty but clean living. Her background and extensive knowledge about the best esthetic procedures and products positions Kelsey as an authority to educate and inform consumers about ingredients that could be harmful.