Living with Mast Cell Activation Syndrome (MCAS) can feel like navigating a stormy sea without a compass. Symptoms can be unpredictable and overwhelming, affecting multiple systems in the body. However, there is hope through innovative integrative treatments that focus on root causes and personalized care. I want to share insights into how combining traditional and holistic approaches can bring lasting relief and improved quality of life. Understanding MCAS and the Need for m

Yoon Hang “John” Kim, MD, MPH, FAAMA Board-Certified Preventive Medicine | Integrative & Functional Medicine | LDN Research Trust Presenter The short version If you’ve been told LDN will make you better but every dose so far has made you worse, you aren’t broken and you aren’t a “bad responder.” You may be a canary patient — exquisitely sensitive, with a depleted endorphin reserve.For canary patients, the standard 1.5 → 4.5 mg climb is too much, too fast. The fix isn’t abando

Looking for a Functional Medicine Doctor in San Antonio? Here's How I Work — From Anywhere in Texas Many patients experience the frustration of pursuing symptom relief for years, moving from one specialist to another, only to receive more prescriptions without real solutions. I am Dr. Yoon Hang "John" Kim, specializing in integrative and functional medicine for complex cases often overlooked by standard practices in San Antonio. My practice operates virtually. I provide care

The LDN Sleep Paradox: Why a Healing Medication Disrupts Your Rest You started Low Dose Naltrexone hoping to feel better — not to lie wide awake at 2 a.m. watching the ceiling fan spin. If your LDN sleep experience has involved vivid, almost cinematic dreams, sudden 3 a.m. wake-ups, or a wired-but-exhausted feeling you can't shake, you're not imagining things. The forums are full of people asking the same question: Is this medication helping me or destroying me? Here's the su

by Yoon Hang Kim MD MPH www.directintegrativecare.com Is Your Naltrexone Causing Headaches? You Aren't Alone That throbbing, pressure-behind-the-eyes pain that hits after your naltrexone dose isn't a sign something has gone terribly wrong — but it is one of the most common reasons people consider stopping the medication altogether. Headaches from naltrexone affect users across the board, whether they're taking a standard 50mg dose for addiction recovery or a much smaller amou

Most people who take a magnesium supplement assume they're covered. They're not — and the reason has almost nothing to do with dosage. According to the Harvard T.H. Chan School of Public Health, approximately 50% of the U.S. population consumes less than the Recommended Dietary Allowance for magnesium. More striking still, up to two-thirds of people in the Western world may never meet their daily needs through diet alone. Yet supplement sales are booming. Something isn't addi

by Yoon Hang Kim MD | www.directintegrativecare.com That frustrating inability to find the right word mid-sentence. The executive function that simply refuses to fire. The sensation that your thoughts are moving through wet concrete. These aren't signs you need more coffee — they're brain fog symptoms, and they represent a specific, measurable cognitive impairment that deserves serious attention. Brain fog is frequently dismissed as tiredness or stress, but that framing is da

Hope: A Biological Imperative for Chronic Illness Recovery Hope isn't a luxury for people living with chronic illness — it's a biological imperative. But before we can understand why, we need to dismantle a persistent misconception: that positive psychology is simply the academic dressing on "think happy thoughts." It isn't. Not even close. Positive psychology, as defined within the Handbook of Positive Psychology framework, is the rigorous scientific study of what allows ind

Chronic disease doesn't fit into a 15-minute slot. Yet for millions of Americans, that rushed appointment window remains the only access point to medical care — a structural mismatch that's quietly driving one of the most significant shifts in modern medicine. The traditional insurance model was built around acute care: diagnose a symptom, prescribe a treatment, move on. For patients managing conditions like autoimmune disorders, metabolic dysfunction, or hormonal imbalances,

Yoon Hang Kim MD www.directintegrativecare.com The Skeptic's Guide to LDN: Is This Really for Pain or Is My Doctor Guessing? If you've ever left a doctor's appointment with a prescription for low dose naltrexone chronic pain management and immediately opened Reddit to ask "is my doctor just winging it?"—you're not alone. That reaction is completely reasonable. Naltrexone has been around since the 1980s as a 50mg addiction treatment, so a doctor prescribing a fraction of that

By Yoon Hang (John) Kim, MD, MPH Board-Certified in Preventive Medicine | Integrative & Functional Medicine Physician www.directintegrativecare.com Introduction Elevated blood sugar — whether due to insulin resistance, prediabetes, or type 2 diabetes — is one of the most common metabolic conditions treated in integrative medicine. Many patients are actively searching for natural ways to lower blood sugar, including evidence-based supplements that can complement lifestyle and

Yoon Hang Kim MD Few topics in integrative oncology spark as much debate as glutathione and cancer . This powerful antioxidant is often celebrated for protecting healthy cells from oxidative damage — yet emerging research reveals a far more complicated story. Studies published in peer-reviewed literature confirm that glutathione can simultaneously shield normal tissue and fuel tumor survival, earning it a reputation as one of biology's most consequential double-edged molecu

by Yoon Hang Kim MD www.directintegrativecare.com Patients send me thoughtful supplement questions almost every week. Some are about products they already own, others about something they read online or heard from a friend. The five below come up often enough that I want to answer them publicly, in the same straightforward way I would during an office visit. My goal is not to promote or dismiss any brand, but to help you match the right formulation to the right goal — and to

By Yoon Hang Kim MD Should you reach for broccoli or a supplement bottle? The debate over calcium food vs supplements is one of the most common nutrition questions asked in doctors' offices today — and the answer is more nuanced than a simple label claim suggests. Where your calcium comes from may matter just as much as how much you're getting. Understanding why that distinction exists starts with physiology. Why the Source Matters: Physiology First The debate over dietary

by Yoon Hang Kim MD www.directintegrativecare.com The Question Behind the Question Can a probiotic strain ease the inflammation driving rheumatoid arthritis ? The growing research around Lactobacillus casei rheumatoid arthritis connections is generating real scientific interest — but the evidence is messier than headlines suggest. Before drawing conclusions, it's worth understanding why the gut keeps entering this conversation at all. Why the Gut Even Enters the Conversatio

By Yoon Hang Kim MD The Cowden Support Program offers one of the most structured herbal-based approaches to managing Lyme disease available today — combining antimicrobial botanicals, detoxification support, and immune modulation into a rotating monthly protocol. Developed by integrative physician Dr. W. Lee Cowden, it addresses the complexity of Lyme and its co-infections in ways that single-agent treatments often cannot. As you explore this guide, you'll discover how the p

Yoon Hang Kim, MD, MPH www.directintegrativecare.com If you live in San Antonio and have been searching for answers about unexplained flushing, hives, brain fog, gut reactivity, food intolerances, dysautonomia, or anaphylaxis-like episodes that no one can quite explain, you may be navigating Mast Cell Activation Syndrome (MCAS). MCAS is one of the most underdiagnosed and most misunderstood conditions I see in my integrative and functional medicine practice. MCAS is a conditi

Low-Dose Naltrexone (LDN): A Functional Medicine Approach to Autoimmunity, Lyme Disease, Long COVID, and Chronic Illness Low-Dose Naltrexone: A Quiet Revolution in Chronic Illness Care Imagine a medication that's been FDA-approved for decades, costs just a few dollars a day, and carries a remarkably mild side effects profile — yet most patients with autoimmune disease, Lyme disease, and Long COVID have never heard of it. That's the reality surrounding low-dose naltrexone (LD

Dr. Kim's Approach to treating MCAS: https://www.ifmsynergy.com/a-functional-medicine-approach-to-mast-cell-activation-syndrome-mcas/ Understanding Mast Cell Activation Syndrome (MCAS) MCAS treatment remains one of the most challenging puzzles in modern medicine — a condition where mast cells misfire, triggering systemic inflammatory responses that affect virtually every organ system. Estimates suggest MCAS may affect up to 17% of the general population, yet it remains widel

Yoon Hang Kim MD www.directintegrativecare.com More than half of American adults take herbal supplements , vitamins, or other dietary products — yet fewer than one-third tell their doctor. That gap between cabinet and conversation is where real safety risks hide. Integrative medicine aims to bridge that gap. But doing so effectively requires patients and providers to move beyond marketing claims and wellness trends toward something more rigorous: honest, evidence-based evalu