RENEW Health & Wellness takes a root-cause, functional medicine approach to the fatigue, chronic symptoms, and health concerns that conventional medicine keeps dismissing.
Personalized plans. Real lab analysis. Results you can feel — in McAllen and the Rio Grande Valley.
Sasha Castillo, MSN, FNP-BC
Family Nurse Practitioner · Functional Medicine Specialist
20+
Years Clinical Experience
100%
Personalized Plans
6
Integrated Services
★ 5.0
Patient-Rated Care
If your labs came back "normal" but you still don't feel right — you're not imagining it. Functional medicine looks deeper, past the standard ranges, into what your body actually needs.
Everything you need to heal from the inside out and feel confident from the outside in.
We dig past the surface complaints into root causes — using advanced lab analysis to uncover hormonal imbalances, nutrient deficiencies, and systemic dysfunction. Then we build a treatment plan around your specific results.
Learn MoreTargeted IV infusions deliver essential nutrients directly into your bloodstream — bypassing digestion for maximum absorption. Faster recovery, sharper energy, and whole-body replenishment.
View All InfusionsPharmaceutical-grade supplements prescribed to you — not what's on the shelf at any pharmacy. Ordered through Fullscript with clinical-grade quality standards tailored to your lab results.
Learn MoreThis isn't another diet program. We address the metabolic, hormonal, and nutritional root causes behind stubborn weight — with a supervised, medically guided plan that creates sustainable, lasting results.
Learn MoreFDA-approved aesthetic treatments administered with the precision and safety standards of a clinical practitioner — not a spa. Look and feel refreshed, with natural, confidence-building results.
Book a ConsultQuick, effective, and precisely dosed — vitamin injections (including B12, D, and specialized blends) provide targeted nutrient delivery when your body needs a fast, reliable boost.
Learn MoreRENEW has partnered with Cherry Payment Plans — apply in seconds, get an instant decision, and start your care today. No hard credit check. Ever.
Applying never affects your credit score. Find out what you qualify for with zero risk.
Qualified patients can split the cost of care into equal monthly payments at zero interest.
Apply in under 60 seconds. Get approved and schedule your care the same day.
Powered by Cherry · Subject to credit approval · Rates and terms vary by applicant
Three clear steps from your first conversation to feeling like yourself again.
We start with a thorough conversation — your symptoms, history, concerns, and goals. No rushing. No dismissing. We actually listen.
We analyze your bloodwork through a functional medicine lens — looking at optimal ranges, not just whether a number is "normal" by conventional standards.
You receive a protocol built entirely around you — specific supplements, infusions, treatments, and follow-up that address your root causes and your goals.
"Sasha pours her love, passion, and faith into the care she provides — and it shows in the results."
— Erica L., RENEW Patient
MSN, FNP-BC · Family Nurse Practitioner
With 20+ years in nursing and a Master of Science in Nursing with a Family Nurse Practitioner specialization, Sasha built RENEW out of a deeply personal conviction: that patients deserve more than a prescription and a dismissal.
Her approach is rooted in faith, scientific rigor, and genuine compassion for every patient she sees — creating a space in the Rio Grande Valley where that level of care is the standard, not the exception.
These aren't curated marketing stories. These are your neighbors, right here in the Rio Grande Valley.
"After more than three years of suffering — and two pulmonologists who couldn't help — Sasha found the answer and started me on the right path. Three months later, all my symptoms are gone. I feel better than I ever did."
"My lab numbers improved so significantly that the iron infusion I was scheduled for was no longer urgent. My own doctor told me to keep following Sasha's plan. She pours her love, passion, and faith into everything she does."
"My labs came back "normal" but I felt sluggish and exhausted. Sasha analyzed them through a functional lens, found my iron, Vitamin D, and ferritin were below optimal — within two weeks of her plan, I felt active and awake again."
"Sasha's analysis of my bloodwork led to a treatment plan that significantly improved my health and well-being. Her warm demeanor, trustworthy advice, and comprehensive knowledge make the journey toward wellness a comforting and successful experience."
"For I know the plans I have for you… plans to give you hope and a future." — Jeremiah 29:11
We believe your body was designed to thrive. When it isn't, there's a reason — and we're committed to finding it. Not managing your symptoms. Not guessing. Finding the reason, and fixing it.
Request Your ConsultationWe don't use templates. Your treatment plan is built from your labs, your history, and your goals — nobody else's.
Internal health and outer confidence are connected. RENEW is one of the few places in the RGV that addresses both with equal expertise and intention.
Sasha brings both clinical precision and a deep faith in the potential for healing to every patient interaction. You're not a chart number here. You're a person.
Located in McAllen and proud to serve patients across Edinburg, Mission, Harlingen, and the entire RGV community.
Conventional medicine treats symptoms. Functional medicine asks why — looking at root causes like nutrient deficiencies, hormonal imbalances, inflammation, and genetic factors. Instead of managing your condition, we aim to resolve it at its source using personalized protocols.
No referral is necessary. You can book your consultation directly. We welcome patients from across McAllen, Edinburg, Mission, Harlingen, and the entire Rio Grande Valley.
Your first visit is a thorough intake — we listen to your full health history, discuss your symptoms and goals, and assess what labs we need. You won't feel rushed. Most initial consultations lead to a lab draw and a follow-up visit to review results and begin your personalized plan.
Yes — this is exactly the patient we're here for. "Normal" in conventional medicine means you fall within a wide population reference range. Functional medicine looks at optimal ranges. Many patients with "normal" labs are significantly below optimal in key markers like ferritin, Vitamin D, B12, and thyroid function.
Yes. RENEW is uniquely positioned to address both internal health and aesthetic confidence. FDA-approved Botox and dermal fillers are administered with the precision and safety standards of a clinical practitioner — not a spa. You can address both at the same practice.
We're located at 500 S. 11th St., Suite 1, McAllen, Texas. Open Monday through Friday, 9AM – 5PM. Closed weekends. Call us at (956) 867-2365 or book directly online.
Rio Grande Valley · McAllen, Texas
You don't have to keep living with symptoms that have no clear answer. Book your consultation with Sasha today, and let's find what's actually going on — and what can be done about it.
