Dr. Tina R. Singh is the Cofounder and Medical Director of Serene Skin and Wellness Medspa in Fairfield, CA, where she blends her expertise in aesthetic medicine with a holistic approach to wellness. A board-certified family physician with over 15 years of experience, Dr. Singh’s passion for dermatology and plastic surgery is deeply personal—having overcome her own skin challenges, she understands the emotional impact of skin concerns. This empathy drives her commitment to providing personalized, cutting-edge treatments like Botox, laser skin correction, medical weight loss, and more, always with meticulous attention to detail and compassion.
Certified in Lifestyle Medicine, Dr. Singh believes lasting beauty starts with overall wellness, integrating nutrition, physical activity, and mental health into her practice. She is devoted to continuous learning and mastering the latest advancements, ensuring the highest quality of care. Outside her practice, Dr. Singh is a devoted mother of three, a culinary enthusiast, and an avid traveler who values humor, family, and cultural exploration. Her vision for Serene Skin and Wellness Medspa is to offer a sanctuary where clients experience transformation—healing both inside and out—guided by a philosophy rooted in excellence, mindfulness, and genuine care.
Neither John Muir Medical Group (JMMG), John Muir Health (JMH) nor the John Muir Physician Network (JMHPN) have any affiliation with this website or entity, or the products, practitioners, physicians, or services featured on this website or marketing materials. JMH, JMHPN and JMMG do not in any way endorse the products, practitioners, physicians, or services featured on this website or marketing materials.
Lenee Cayabyab is a licensed and board-certified Family Nurse Practitioner specializing in dermatology and aesthetic medicine, with over 15 years of healthcare experience. She is passionate about helping patients achieve healthy, radiant skin through a comprehensive and personalized approach to care.
She graduated magna cum laude from the Doctor of Nursing Practice/Family Nurse Practitioner (DNP/FNP) program at Samuel Merritt University. She is board certified by the American Nurses Credentialing Center and is a member of the Society of Dermatology Nurse Practitioners.
Prior to joining Serene Skin and Wellness MedSpa, Lenee worked in a high-volume dermatology practice in the Central Valley, where she gained extensive experience in medical, surgical, and cosmetic dermatology. She has advanced training in aesthetic treatments, including neurotoxins, dermal fillers, laser therapies, skin rejuvenation procedures, and skin regenerative treatments. Her experience working closely with dermatologists and dermatologic surgeons has provided her with a strong clinical foundation and an artistic eye for natural-looking, balanced results. She continues to practice dermatology part-time, maintaining her expertise across medical, surgical, and cosmetic care.
Lenee is dedicated to patient-centered care, taking the time to understand each individual’s goals, preferences, and values. She believes in creating customized treatment plans that enhance natural beauty, facial harmonization while maintaining skin health and integrity.
A Bay Area native, Lenee enjoys traveling the world and exploring new cultures. She also loves spending time with her family, trying new foods, cooking, and visiting national parks.
Kimberly Shaul, FNP-BC, is a board-certified Family Nurse Practitioner specializing in aesthetic medicine and functional wellness. With several years of experience in pain management and a clinical background in Labor & Delivery and NICU care, she brings a precise, compassionate approach to every patient interaction.
Her philosophy is rooted in individualized care—blending advanced aesthetic treatments such as neurotoxins, dermal fillers, and skin rejuvenation with functional wellness strategies to support long-term health and natural-looking results. Kimberly is known for her attention to detail, refined technique, and ability to create balanced, personalized outcomes.
She holds a Master’s degree in Nursing from the University of Cincinnati with a strong commitment to ongoing education and innovation.
Outside of her practice, Kimberly enjoys time with her husband, two children, and their dog, often exploring Napa Valley and staying active outdoors. She is dedicated to creating an elevated, welcoming experience where patients feel confident, supported, and empowered in their transformation.
Janice Pagtakhan is a dedicated and highly skilled Registered Nurse with over 20 years of experience, specializing in aesthetic nursing at Serene Skin & Wellness Medspa. Her true passion lies in helping clients enhance their natural beauty through advanced, personalized aesthetic treatments in a serene and supportive environment.
With extensive training and certifications in numerous laser applications—including laser hair removal, skin laser treatments, medical grade peels, microneedling, skin tightening—as well as injectable medications and IV therapy, Janice brings a wealth of expertise and an artistic eye to every procedure. Her unique techniques and meticulous approach have delivered exceptional, noticeable results.
Janice is deeply committed to patient-centered aesthetics. She treats every individual with compassion, taking the time to understand their unique goals and crafting tailored treatment plans that blend science, artistry, and wellness for natural-looking, radiant outcomes. She believes true beauty enhancement is both an art and a science—and she has a genuine talent for it.
When she’s not at the medspa, Janice enjoys spending quality time with her husband and three children, traveling, reading, skating, and volunteering in the community. Her warm, caring nature shines through in everything she does, making clients feel confident, refreshed, and truly cared for.
