✦ The TDG Five-Test Programme

Five tests. Seven systems.
One protocol built around your results.

After 37 years in clinical practice, I have yet to encounter a case of persistent, significant symptoms where comprehensive functional testing found absolutely nothing. The symptoms are messages. The TDG Programme is how you read them — and address them.

5Advanced tests

900+Data points

7Body systems

37yrClinical experience

Book a discovery consultation → How it works

Discovery consultation is complimentary — no obligation

Why people come to TDG

You've been through the NHS route. You've had the standard blood tests. You've been told everything is normal. And you still don't feel well.

Standard medicine is excellent at identifying disease. It is not designed to identify the territory between optimal health and diagnosed disease — the zone where most people with persistent symptoms actually live. Functional testing maps that territory with precision.

The conditions below are the most common presentations in the TDG programme. Most clients arrive having already spent years being investigated, reassured, and sent away without answers.

Persistent fatigue Brain fog IBS / gut dysfunction Hormonal imbalance Thyroid symptoms (normal TSH) Weight resistance Anxiety & low mood Poor sleep Autoimmune conditions Perimenopause / menopause Skin conditions Recurrent infections

The five tests

Comprehensive functional investigation
across every major body system.

Each test addresses a different dimension of your health. Together they produce a complete picture that standard medicine — testing one system at a time — structurally cannot provide.

Comprehensive Blood Chemistry

60+ markers across thyroid, metabolic, iron, inflammatory, liver, vitamins and minerals, lipids, full blood count, and kidney. Interpreted to functional optimal ranges — not just conventional normal. Includes 10 calculated ratios your standard lab report doesn't show.

60+ markers

Medichecks / Forth

GI-MAP Stool Analysis

DNA-based stool testing identifying pathogens, parasites, digestive function, gut immune markers, intestinal permeability, and microbiome composition. Detects organisms that standard stool culture routinely misses — including Blastocystis, Giardia, and H. pylori virulence factors.

35+ markers

Genova Diagnostics

DUTCH Plus Hormone Panel

The most comprehensive commercially available hormone test — four cortisol samples plus the cortisol awakening response, complete oestrogen pathway mapping (2-OH, 4-OH, 16-OH, 2-methoxy), progesterone, testosterone, melatonin, and organic acid markers for B12, B6, glutathione, serotonin, and dopamine.

40+ markers

Regenerus Labs

Organic Acids Test (OAT)

Urine-based metabolic snapshot revealing mitochondrial function, nutrient cofactor status, neurotransmitter metabolism, detoxification capacity, and yeast and bacterial overgrowth markers. The test that connects symptoms to cellular-level dysfunction.

70+ markers

Genova / Great Plains

Food Sensitivity Panel

IgG-based food reactivity testing across 200+ foods. Identifies the dietary triggers driving systemic inflammation, gut permeability, and immune activation. Essential context for the nutritional protocol — removing reactive foods without this data is guesswork.

200+ foods

Lorisian / YorkTest

How the programme works

A structured clinical process — not a one-off consultation.

The TDG Programme is a complete clinical investigation, not a single appointment. Everything is sequenced deliberately — each phase builds on the last.

Discovery consultation

Complimentary 30-minute call. We review your history, your symptoms, and confirm TDG is the right fit. No obligation.

Test kit dispatch

All five test kits are arranged and dispatched. Detailed instructions provided. Tests are completed at home on your schedule.

Clinical analysis

Results are analysed across all five tests simultaneously — mapping patterns across systems that single-test interpretation structurally misses.

Results consultation

A full 60-minute consultation presenting your findings, the clinical patterns identified, and the priority intervention sequence.

Written protocol

A comprehensive written protocol covering nutrition, supplementation, lifestyle, and the sequenced intervention hierarchy based on your specific results.

Follow-up support

Check-in consultations at 6 and 12 weeks to review progress, adjust the protocol, and plan reassessment testing.

Clinical focus areas

The twelve conditions TDG investigates most frequently.

These are presentations where functional testing consistently reveals what standard investigation misses — the root cause rather than the symptom.

Persistent Fatigue

Mitochondrial dysfunction, iron deficiency, HPA exhaustion, thyroid conversion failure — four distinct root causes that look identical symptomatically.

IBS & Gut Dysfunction

Pathogen burden, gut permeability, microbiome disruption, enzyme insufficiency — addressable once identified. Often present for years before testing.

Hormonal Imbalance

Oestrogen dominance, progesterone deficiency, pregnenolone steal — patterns invisible to standard blood oestrogen and progesterone testing.

Thyroid (Normal TSH)

T4-to-T3 conversion failure, Hashimoto's with normal TSH, reverse T3 elevation — the most common missed thyroid pattern in functional medicine.

Weight Resistance

Insulin resistance, thyroid dysfunction, HPA axis disruption, gut microbiome imbalance — the metabolic drivers that make standard dietary advice ineffective.

Anxiety & Low Mood

Gut-driven neurotransmitter depletion, HPA dysregulation, nutrient deficiency (B12, iron, vitamin D, magnesium) — addressable biological drivers.

Brain Fog

Blood glucose dysregulation, neuroinflammation, mitochondrial dysfunction, methylation impairment — cognitive symptoms with measurable metabolic causes.

Perimenopause / Menopause

Complete hormonal picture including oestrogen pathway safety markers (4-OH oestrogens) that standard HRT monitoring does not assess.

Autoimmune Conditions

Gut permeability, molecular mimicry, HPA axis dysregulation — the upstream drivers of autoimmune activation that are addressable with the right intervention.

Poor Sleep

Melatonin synthesis failure, elevated evening cortisol, blood glucose instability, gut serotonin depletion — sleep problems rarely lack a measurable cause.

Skin Conditions

Gut-skin axis disruption, food reactivity, inflammation, hormonal drivers — skin is often the external presentation of internal gut and hormonal dysfunction.

Recurrent Infections

sIgA depletion, HPA exhaustion, nutritional deficiencies (zinc, vitamin D) — compromised immune resilience has identifiable and addressable drivers.

Is TDG right for you

This programme is designed for a specific type of person.

TDG is right for you if…

✦You have persistent symptoms that haven't been explained by standard investigation

✦You've been told results are normal but you don't feel well

✦You're ready to invest in a thorough, root-cause investigation

✦You want a written protocol you can follow, not just a conversation

✦You understand this is a programme, not a quick fix

✦You're committed to implementing the protocol with consistency

TDG may not be the right fit if…

—You're looking for a prescription or GP referral (I'm not a medical doctor)

—You want a single appointment with immediate answers

—You're not prepared to make dietary and lifestyle changes

—You have an acute condition requiring urgent medical attention

—You're looking for the cheapest possible option

"Normal and optimal are not the same number. The gap between them is where your symptoms live — and it is precisely the territory that comprehensive functional testing is designed to map."

Stephen Duncan MSc FDN-P · Founder, Detective Health

The investment

The TDG Programme is a comprehensive clinical investigation. The fee covers the full programme — consultation, testing coordination, clinical analysis, results consultation, written protocol, and follow-up support.

TDG Five-Test Programme

^£3,500

Test costs are additional — arranged directly with laboratories (approx. £600–800 depending on panel)

✦Discovery consultation (30 min, complimentary)

✦All five test kits arranged and coordinated

✦Full clinical analysis across all five tests simultaneously

✦Results consultation (60 min)

✦Comprehensive written clinical protocol

✦Follow-up consultations at 6 and 12 weeks

✦Email support throughout the programme

Book your discovery consultation →

Discovery consultation is complimentary and without obligation

Not ready for the full programme? The interpretation guides are a powerful self-guided starting point at £197 each — or speak to us about the Resilient Gut System programme.

Your practitioner

37 years. One framework. Built on testing.

Stephen Duncan

MSc · FDN-P · Edinburgh

MSc Functional Nutrition

Functional Diagnostic Nutrition Practitioner (FDN-P)

Reed Davis FDN Model

Bill Wolcott Metabolic Typing (Healthexcel)

Bryan Walsh Blood Chemistry

Paul Chek Movement Framework

Co-founder, Omnos functional lab platform

Founder, Detective Health

I started in athletics and boxing coaching before spending nearly four decades working with clients whose symptoms were real but whose investigations kept coming back normal. That gap — between feeling unwell and getting an explanation — is what the TDG programme was built to close.

The Test, Don't Guess philosophy is not complicated. You cannot optimise what you haven't measured. You cannot address root causes you haven't identified. And you cannot build a credible protocol from a single test viewed in isolation.

Every protocol I produce is built from the intersection of five test results, viewed through seven body systems, informed by 37 years of pattern recognition. There is no template. Everything is specific to your results.

Common questions

Before you apply.

How long does the programme take?

From discovery consultation to written protocol is typically 6–8 weeks — most of that is waiting for test results. Active consultation time is 90 minutes across the programme. The implementation phase runs 3–6 months.

Do I need a GP referral?

No. All tests are arranged privately and directly. You don't need a GP referral, and you don't need to have seen a doctor first. That said, TDG doesn't replace your GP — we work alongside conventional medicine.

Are the consultations in person or online?

All consultations are conducted via video call. Clients are based across the UK and internationally. Test kits are posted directly to your address regardless of location.

What if my results come back relatively normal?

In 37 years of practice, I have never seen a case of persistent significant symptoms where five comprehensive functional tests found absolutely nothing. The question is usually not whether something is present — it's knowing where to look.

Is the programme suitable for men as well as women?

Yes. The programme is appropriate for any adult experiencing persistent symptoms. The test panels and reference ranges are fully sex-specific where clinically relevant.

What happens after the 12-week follow-up?

Most clients continue with a reassessment protocol — retesting the most relevant markers at 6–12 months to confirm progress and refine the approach. Ongoing support is available as needed.

Five tests. Seven systems.One protocol built around your results.