Dr. Sarah Khan, PhD, MBA · Integrative & Functional Nutrition
Online Functional Nutritionist for Gut, Thyroid, and Autoimmune Health
Your labs keep coming back normal, but you still feel awful. I work virtually with clients across the United States to find what is actually driving your symptoms, then build a plan around your biology instead of a generic template.
Not sure where to start? Take the free 2-minute Root Cause Quiz
You do not need to live in New York to get real answers
Most people who find me have already seen several practitioners. They have been told everything looks fine. They have tried elimination diets, probiotics, and a cabinet full of supplements, and they still feel exhausted, bloated, foggy, or inflamed.
The problem is almost never a missing supplement. It is that no one has asked why your body is responding this way. That question does not require us to be in the same room.
This is usually the pattern:
- You are exhausted no matter how much you sleep. Wired and depleted at the same time.
- Your digestion runs your life. Bloating, IBS, or reacting to foods you used to tolerate.
- The brain fog will not lift. Focus takes effort it never used to.
- Your hormones feel off and nothing you try seems to move them.
- You are managing an autoimmune condition and living with the flares.
- Your labs come back normal and you are tired of being dismissed.
What working together online actually looks like
Same depth, same concierge access, no commute.
Step 01
Comprehensive Assessment
You complete a detailed intake covering your health history, major life events, current diet, medications, and daily routines. I review every lab you already have before we ever meet.
Step 02
Your Personalized Protocol
We meet by video for an in-depth review. You leave with a sequenced nutrition and lifestyle plan built around your biology and your actual schedule, plus a written guide to implement it.
Step 03
Ongoing Refinement
Between sessions you have direct access to me for questions and real-time adjustments. Healing is rarely linear, so we track, retest when it helps, and adjust as we go.
What I work on with virtual clients
These overlap far more than most people realize, which is often why earlier attempts did not hold.
SIBO and IMO
Hydrogen, methane, and hydrogen sulfide overgrowth. Breath testing ships to you at home anywhere in the country.
Gut Health and IBS
Bloating, reflux, food sensitivities, and irregular digestion that a restrictive diet alone never resolved.
Hashimoto’s and Thyroid
Fatigue, hair loss, and rising antibodies, addressed through the gut, blood sugar, and nutrient status driving them.
Autoimmune Disease
Fewer flares and a body that feels stable again, by looking at the systems driving immune activity.
Hormone Imbalances
Hormone symptoms are usually downstream of blood sugar, gut function, liver health, and stress physiology.
Perimenopause
Weight, mood, sleep, and energy shifts in your 30s and 40s that do not match what you are doing.
Does online functional nutrition work as well as in person?
In this work, yes. Functional nutrition is built on your history, your symptom timeline, your labs, and how your systems interact. All of that travels perfectly well over video. There is no physical exam that changes the plan, and I am not diagnosing disease or adjusting your medications. That stays with your physician.
What actually determines results is the depth of the assessment and the quality of the follow-up. Virtual clients get the same comprehensive intake, the same lab interpretation, and the same concierge access between sessions as anyone I see at my Manhattan office.
Functional testing ships to your door
When testing adds clarity, at-home collection kits are mailed to you anywhere in the country. That includes SIBO and IMO breath testing, comprehensive stool testing, full thyroid panels, and hormone testing. You collect at home, the lab processes it, and we review the results together on video.
I use testing to confirm what your symptoms are already pointing toward and to make your plan more precise, never to order for its own sake. You will not be left with a printout and no direction.
What clients say
★★★★★ 5.0 on Google · 21 five-star reviews
★★★★★
“In 20 years of dealing with health issues, I have never found someone more willing to help me find relief.”
She approaches each client dimensionally and offers life-changing solutions for every aspect of health. I had often felt left on an island by conventional medicine. Now I have someone in the trenches with me.
Alisha R.
★★★★★
“As a skeptic, I was relieved by the scientific, detailed explanations she provided.”
Sarah gave me extremely personalized advice and created a safe space to discuss my health in detail. She truly listens and encourages diverse, expert ways to tackle health concerns.
Aditya A.
★★★★★
“It is so reassuring to finally know exactly what is going on with my body.”
It is hard having sleep issues and getting no answers from doctors, but Sarah knows exactly what to pinpoint and improve. She is also extremely kind and empathetic.
Nathan A.
Frequently asked questions
Which states do you work with clients in?
All of them. I see clients virtually across the United States. Functional nutrition is educational and lifestyle-based rather than diagnostic, so I am able to work with you wherever you live. Most of my clients are in New York and the surrounding area, but location does not affect the depth of the work.
How is functional nutrition different from seeing a regular dietitian?
Functional nutrition looks for the root cause of your symptoms rather than managing them one at a time. Instead of asking only what you should eat, I ask why your body is responding the way it is, what is happening with your gut, your thyroid, your hormones, and your stress physiology, and then build a plan around your biology rather than a generic template.
Can I do functional lab testing if I am not local to NYC?
Yes. At-home collection kits ship anywhere in the country, including SIBO and IMO breath tests, comprehensive stool testing, thyroid panels, and hormone testing. You collect the sample at home and mail it back, and we review the results together on video. I also look closely at any standard bloodwork you already have.
Do you accept insurance, HSA, or FSA?
No. Working privately lets me give the personalized, concierge-level attention this work requires, without the limits insurance places on time and approach.
Will you work alongside my doctor?
Absolutely. Functional nutrition is meant to complement your medical care, not replace it. I do not diagnose disease or change your medications, that stays with your physician. What I add is the nutrition and lifestyle layer most conventional visits do not have time for, and I am glad to coordinate so everyone is working toward the same goal.
How long until I see results?
Most clients notice early shifts, such as better energy, less bloating, and steadier mood, within the first few weeks. Deeper change, like calming an autoimmune flare or rebalancing hormones, usually unfolds over a few months as we work through the root causes in order. Healing is rarely linear, which is one reason the programs are built around ongoing support rather than a single visit.
How do I get started?
The first step is a free discovery call. It is where we talk through what you have been experiencing, decide whether we are a good fit, and choose the right level of support together. If you are not sure where your symptoms are coming from yet, you can take the free Root Cause Quick Scan first as a low-pressure way to begin.
Ready to stop guessing?
Book a free discovery call and we will talk through what you have been experiencing, whether we are a good fit, and what the right level of support looks like. Wherever you are in the country.
Dr. Sarah Khan, PhD, MBA · Integrative & Functional Nutrition
136 Madison Avenue, New York, NY 10016 · Seeing clients virtually nationwide