603-856-0372 603-856-0372  ·  Now accepting new patients  ·  In-person in NH + telehealth in 4 states. Schedule a discovery call →
Functional Medicine. Done Right.

You’re not imagining it.
And we can prove it.

If conventional medicine has dismissed you, brushed off your symptoms, or told you your labs are “normal” while you feel anything but — you’re in the right place. We use precision functional testing and root-cause clinical investigation to find what’s actually happening in your body. Then we fix it.

5,000+
Patients treated since 2014
5
States licensed for telehealth
93%
Patient satisfaction rating
Dr. Seth Osgood, DNP, FNP-BC, IFM-CP, in his clinic
Founder's note
"I built this clinic because I was the patient conventional medicine almost lost."

DNP, FNP-BC

Doctorate of Nursing

IFM-CP

IFM Certified

11+ years

Clinical practice

5,000+

Patients served

NH · VT · TX · FL

In-person + Telehealth
Dr. Seth Osgood consulting with a patient at GrassRoots Functional Medicine

“Several years ago, conventional medicine almost gave up on me. That’s why I’ll never give up on you.”

Why I Built GrassRoots

I was the patient. Now I'm the clinician.

Several years ago, I was a high-performing clinician with debilitating neurological symptoms. Brain fog. Tremors. Joint pain. Cognitive decline.

I went to specialists. Multiple MRI lesions were found. Every test came back “normal.” I was told my symptoms were stress. Then anxiety. Then I needed antidepressants.

No one was investigating why. They were just managing the label.

Six months later, an IGeneX test revealed what conventional serology had missed: Lyme disease and co-infections — the same test most clinics still don’t order.

I treated it with a protocol that blended conventional antibiotics, strategic herbal medicine, nutrition, peptides, and lifestyle medicine. Within 8 weeks, my symptoms began reversing. Within 6 months, I was symptom-free.

The bigger realization: conventional and functional medicine aren’t enemies. They’re incomplete without each other.

I built GrassRoots to be the clinic I needed back then. A place where patients aren’t dismissed. Where testing is precise, not perfunctory. Where we don’t choose between conventional rigor and functional depth — we use both.

Doctorate of Nursing Practice Family Nurse Practitioner, Board Certified IFM Certified Practitioner Host, GrassRoots Functional Medicine Podcast

Not another wellness clinic. A clinical operating system.

Most functional medicine clinics run the same panels, recommend the same supplements, and produce the same vague results. We rebuilt the model from the ground up.

Precision functional testing

We use Genova Diagnostics, Doctor’s Data, US Biotek, IGeneX for tickborne illness, Vibrant Wellness, urine mycotoxin panels, salivary cortisol, and leaky gut markers. We test what answers questions — not what insurance “allows”.

Metabolic optimization, not just weight loss

GLP-1s can work — but only with muscle preservation, PNOE metabolic testing, InBody body composition tracking, and progressive strength protocols built in.

Conventional + functional integration

Your case needs antibiotics? We prescribe them. Needs herbs and nutrition first? We do that. Needs both? Standard protocol. We blend evidence — not ideology.

Comprehensive intake — included

Bloodwork, PNOE metabolic testing, and InBody body composition are included in your intake assessment. Most clinics charge separately for each.

Strategic peptide therapy

Peptides aren’t a trend — they’re a tool. We use them strategically for tissue repair, immune modulation, neurological support, and metabolic health, with proper oversight.

Real lab interpretation

No “normal range” hiding. We dig into optimal ranges, pattern recognition, antibody trends, and root-cause clues that standard reads miss entirely.
As featured
across:

The illnesses other clinics miss or mismanage.

If you’re chronically symptomatic and your labs keep coming back “normal” — there’s a strong chance one of these is at the root of it.

Lyme & Co-Infections

IGeneX testing, integrated antibiotic + herbal protocols, mast cell support, neurological recovery.

Thyroid & Hashimoto's

Antibody reduction, T3/T4 conversion, gut-thyroid axis repair, optimal hormone restoration.

Chronic Fatigue & ME/CFS

Mitochondrial assessments and testing, adrenal recovery, post-exertional malaise protocols.

Gut Health & SIBO

SIBO breath testing, advanced stool analysis, leaky gut repair, microbiome restoration.

Autoimmune Conditions

Root-cause investigation for RA, lupus, MS, psoriasis, and ulcerative colitis. Low-dose immunotherapy available.

Mold & CIRS

Urine mycotoxin testing, environmental assessment, biotoxin clearance, neurological recovery.

GLP-1 & Metabolic Reset

PNOE testing, InBody composition tracking, muscle-preserving GLP-1 protocols, peptide adjuncts.

Hormone Optimization

Bioidentical HRT, perimenopause, low testosterone, adrenal optimization, fertility support.

Brain Fog & Cognitive Decline

Inflammatory marker workup, neuroinflammation protocols, peptide support, mitochondrial care.

Not ready to book? Start where you are.

Not every patient is ready to schedule a consultation on day one — and that’s okay. Choose the entry point that matches where you are right now.

/ Step One — Free

Get the Knowledge Hub

Instant access to 50+ free resources: case studies, root-cause guides, condition deep-dives, and protocols. Built by Dr. Osgood for patients who want real answers — not surface-level advice.

Get Free Access →
No signup wall. Browse everything.
/ Step Two — Watch

See how we work

Watch a 5-minute walkthrough of a real patient case — from chronic symptoms to root-cause diagnosis to full recovery. See exactly how we test, treat, and track outcomes.

Watch the Walkthrough →
5 minutes. Real patient. Real results.

Specific results. Real patients. Measurable change.

We don’t trade in vague “I feel great now” testimonials. Every patient case includes the diagnosis, the protocol, and the measurable outcome.

TPO antibodies: 487 → 62 in 6 months. Off Synthroid.

“I’d been on thyroid medication for seven years with no real improvement. Dr. Osgood looked at the full picture — gut health, adrenal function, food sensitivities — and rebuilt my protocol. I feel like myself again.”

Jennifer K., 42

Jennifer K., 42

Hashimoto’s · Chronic Fatigue

Symptom-free after 8 years. Working full capacity.

“Conventional rheumatology said my Lyme was “cured.” IGeneX testing showed active co-infections. Dr. Osgood’s integrated protocol — antibiotics, herbs, peptides, lifestyle — cleared it. No brain fog. No fatigue. No compromise.

Marcus T., 51<br />

Marcus T., 51

Lyme Disease · Co-Infections

Lost 18 lbs. Preserved muscle. Energy optimized.

“I was terrified of losing muscle on GLP-1. GrassRoots protocol — PNOE, InBody, targeted strength training, peptides — kept me strong while the fat came off. This is how weight loss should actually work.

Amanda L., 38<br />

Amanda L., 38

Metabolic Reset · GLP-1

Real education. Free. Always.

50+ root-cause deep-dives written by Dr. Osgood. Lyme. Hashimoto’s. GLP-1 truth. CIRS. Gut health. No fluff. No upsells. Just real medicine.

Tickborne Lyme disease guide
The Lyme Patient's Guide to Real Testing
Metabolic Dr. Seth Osgood on the GrassRoots Functional Medicine Podcast
The Truth About GLP-1s & Muscle Loss
Hormones Hashimoto's guide
Reversing Hashimoto's at the Root
Environmental Mold and CIRS
When Your Home Is Making You Sick

In-person in New Hampshire. Real patients. Measurable change.

Our clinic in West Lebanon, NH serves patients throughout a 60-mile radius — including the Upper Valley NH/VT region and the Champlain Valley patient corridor. Patients also travel in from across New England and beyond for the comprehensive intake assessment. Ongoing care is delivered in-person or via telehealth in Texas, Florida, Vermont, and New Hampshire.

In-Person Clinic

The Upper Valley

89 South Main Street, West Lebanon, NH 03784
Monday–Thursday, 8:00 AM – 5:00 PM

Serving NH: Hanover, Lebanon, Enfield, Lyme, New London, Claremont, Cornish, Grantham, Orford, plus surrounding communities.

Serving VT: White River Junction, Norwich, Woodstock, Hartford, Hartland, Thetford, Fairlee, plus the wider Upper Valley.

Patient Travel Corridor

Champlain Valley & Beyond

Patients travel from across the region for in-person care at our West Lebanon clinic.

Common patient origins: Plattsburgh NY, Burlington VT, Saranac Lake, Lake Placid, Tupper Lake, Middlebury VT, plus Boston metro and southern New England.

If you can travel for the initial assessment, we can build a long-term care plan around your geography.

Telehealth

Texas, Florida, VT & NH

Licensed for telehealth in Texas, Florida, Vermont, and New Hampshire. Same comprehensive care, delivered remotely.

Texas patients: Austin, Houston, Dallas-Fort Worth, San Antonio metro areas, plus the Hill Country and surrounding communities.

Florida patients: statewide telehealth access.

You’ve waited long enough for answers.

Your Discovery Call is 30 minutes, no charge, and no pressure. We’ll review your history, explain how we’d approach your case, and tell you honestly whether we’re the right fit. If we’re not — we’ll point you somewhere that is.

Limited spots each week · Reserved for serious patients · 888-644-7668