Our Team
Penninah Muthoka, MSN, APRN, PMHNP-BC, is a Board-Certified Psychiatric Mental Health Nurse Practitioner dedicated to providing compassionate, evidence-based mental health care. With more than five years of clinical experience, she helps individuals achieve emotional wellness through personalized, holistic, and patient-centered treatment. As a provider at Sage Behavioral Health, doing business as Sage and Serotonin Integrative Mental Health, Penninah is committed to supporting patients on their journey toward improved mental health and overall well-being.
Penninah provides care for children ages 10 and older, adolescents, adults, and older adults. She has extensive experience assessing, diagnosing, and treating a wide range of mental health conditions, including anxiety disorders, depression, ADHD, bipolar disorder, obsessive-compulsive disorder (OCD), trauma-related disorders, sleep disturbances, women’s mental health concerns, addiction, and other mood and stress-related conditions.
Her approach to care is rooted in the understanding that mental health is closely connected to physical health, emotional well-being, social relationships, and lifestyle factors. Penninah works collaboratively with each patient to develop individualized treatment plans that align with their unique goals, values, and life circumstances. By integrating psychiatric medication management, patient education, and wellness-focused strategies, she helps patients build resilience and create meaningful, lasting change.
Penninah is committed to fostering a safe, welcoming, and nonjudgmental environment where patients feel heard, respected, and empowered. She values strong therapeutic relationships and believes that collaborative care is essential for achieving positive and sustainable outcomes.
Dedicated to lifelong learning and clinical excellence, Penninah stays current with advances in psychiatric treatment and integrative mental health practices. Her goal is to help patients develop greater self-awareness, strengthen emotional well-being, and enhance their overall quality of life.
Outside of her clinical practice, Penninah enjoys road trips, traveling, sports, and exploring new places. These interests reflect her commitment to balance, personal growth, and wellness, values she brings to her work with every patient.
Penninah Muthoka, APRN, PMHNP-BC
Hilder Njoroge, MSN, APRN, BS-HSA, PMHNP-BC
Hilder is a board-certified Psychiatric Mental Health Nurse Practitioner. Hilder works with patients ages 15 years and older, offering a supportive and compassionate space for healing. She begins with holistic and lifestyle approaches before medications. She also supports safe de-prescribing when appropriate, with a focus on empowering patients to make informed, confident choices about their care.
Hilder’s style is relational, gentle, and grounded in genuine respect. She uses psychoeducation, group therapy, and reading-based discussions to help patients better understand their mental health and feel less alone in their journey. Book clubs and group learning are some of her favorite ways to help people connect, grow, and heal together. She often shares that she learns just as much from her patients as they learn from her.
Hilder has more than 16 years of nursing experience at The University of Kansas Health System. During her time there she worked in various units as a Registered Nurse but was based on her home unit in a surgical urology/gynecology cardiac unit which has strengthened her broad clinical expertise and adaptability. Hilder brings a deep understanding of how physical and mental health intertwine. She also worked as an LPN in home health and long-term care, shaping her gentle, patient-first approach.
Her professional journey—from LPN to Master’s-prepared PMHNP—reflects a lifelong commitment to serving others with humility, curiosity, and compassion. Hilder earned her MSN from Walden University, her BSN from MidAmerica Nazarene University, and her Bachelor of Science in Health Services Administration from Upper Iowa University. She practices with holistic, trauma-informed, and culturally sensitive lens.
Outside of work, she enjoys reading, being outdoors, walking, and spending quality time with her family and friends..
Amanda Hill, MSN, APRN, CNM, PMHNP-BC
Amanda is a highly experienced, dual-certified advanced practice provider with over two decades of nursing and healthcare experience. Her board certifications as a Psychiatric Mental Health Nurse Practitioner (PMHNP-BC) and Certified Nurse Midwife (CNM) enable her to provide comprehensive, holistic mental health care tailored to individuals across the age spectrum.
Additionally, she focuses on women's mental health throughout their lives, from pregnancy and postpartum to managing PMS/PMDD, perimenopause, and menopause. She combines medication with a holistic approach, using her knowledge of hormones, lifestyle changes, and trauma-informed care. Besides her expertise in women's health, she also offers general psychiatric services to children aged 10 years and above, teens, and adults, regardless of gender. Furthermore, Amanda provides support and treatment for conditions like anxiety, depression, ADHD, insomnia, PTSD, schizophrenia, personality, and mood disorders.
With a rich and varied background, she has worked in diverse clinical settings, such as midwifery, newborn ICU, nurseries, perinatal and postpartum care, radiology, IV therapy, weight management, urgent care, family practice, and long-term care facilities, demonstrating her extensive and adaptable clinical skills.
Outside of work, Amanda enjoys spending time with her family, traveling, biking, and pursuing creative hobbies. She appreciates opportunities to explore new places, connect with loved ones, and maintain an active lifestyle. These interests reflect her belief that mental, physical, and emotional well-being are closely connected and play an important role in living a healthy, balanced life.