Self-Directed Health Investigation Starter Kit

Test, Don't Guess.
Start here.

Your GP ran the tests. Everything came back normal. You still feel terrible.
The gap between normal and optimal is where most chronic health problems live — and where this kit begins.

£127 Instant download · Includes platform access · Personal written response
Get the Starter Kit What's included ↓
131-page clinical guide PDF + HTML editions 46 self-assessment tools Intake forms reviewed personally Foundation Reset movement plan 37 years clinical experience

"I have yet to encounter a case of persistent, significant symptoms where comprehensive functional testing found absolutely nothing."

Stephen Duncan FDN-P MSc · 37 years of clinical practice · Edinburgh

Why generic advice fails

Normal is not the same as optimal.

Standard testing uses population reference ranges. Functional medicine uses optimal ranges — and the gap between them is where most chronic symptoms go unexplained for years, sometimes decades.

Your ferritin is "normal"

A ferritin of 18 falls within NHS reference range. The functional optimal for sustained energy, thyroid hormone conversion, and dopamine transport is 50–100 ng/mL. That gap explains the exhaustion nobody can account for.

Your glucose is "fine"

Fasting glucose without fasting insulin tells you almost nothing. Insulin rises a decade before blood sugar — and the dysglycaemic cycle driving your 3am waking, afternoon crashes, and carbohydrate cravings won't appear on a standard panel.

Your stress is "just life"

The UK has a cultural habit of minimising stress. But chronic psychological stress triggers the pregnenolone steal, collapses sex hormone production, suppresses digestive function, and creates gut symptoms that no amount of probiotics will fix if the root cause goes unaddressed.

Your supplements aren't working

Supplementation is Layer 7 of the intervention hierarchy, not Layer 1. Starting with supplements without understanding what's actually driving your symptoms is expensive guesswork. The Starter Kit teaches you why — and what to do instead.

Everything included

Five components. One framework.

Not a PDF and a password. A complete self-directed investigation framework with a personal clinical response built in.

01

Test, Don't Guess — The Book

131 pages. 20 chapters. The complete functional medicine investigation framework in plain language — from why conventional advice fails to a full walkthrough of the seven body systems, five functional tests, and how to build a protocol built entirely around your biology.

  • Part I — Foundations: Why generic advice fails, the five-test approach, the intervention hierarchy, the psychology of sustainable change
  • Part II — The Seven Body Systems: Nervous system, digestive health, hormonal balance, metabolic health and blood sugar, inflammation, sleep and circadian health, movement and exercise
  • Part III — Taking Action: The five tests in depth, nutrition, supplementation, lifestyle, your personalised protocol, and a 12-condition quick guide
  • 12 clinical diagrams, normal vs optimal reference tables, three detailed case studies, The Non-Negotiables quick reference
PDF + HTML editions included
02

The Detective Health Checklist

Functional lab reference ranges, movement, stress, nutrition and lifestyle assessment with personal action plan. A working reference document you will return to repeatedly — not a summary sheet, not a freebie PDF.

Practitioner-designed reference
03

3 Months TDG Platform Access

46 clinical self-assessment tools covering blood sugar patterns, breathing function, weight loss resistance, gut health, neurodivergent presentation, food logging, daily tracking, movement assessment, lifestyle audit, allostatic load, and more. The same platform used by TDG programme clients.

Complete the tools at your own pace. Understand your patterns. Know exactly what to ask for — and why.

46 tools · 3 months access
04

Four Intake Forms — Personally Reviewed by Stephen

After purchase, email hello@detective-health.com with the subject line "Starter Kit Access" to receive your platform link. Complete the four core intake forms and return them. Within 5 working days you receive a written personal response covering your primary health patterns, what to prioritise first, and whether functional testing is indicated for your case.

  • Health Story & History — your full health timeline, medications, presenting concerns
  • Symptom Burden — systematic scoring across all body systems
  • Lifestyle Audit — sleep, stress, movement, environment, work patterns
  • Food Log — three-day dietary record, reactions, eating patterns

This is not an automated report. It is a personal written response from a practitioner with 37 years of clinical experience.

Personal written response · Within 5 working days
05

The Foundation Reset — Your Movement Blueprint

Based on your Movement History intake form, you receive a personalised movement programme alongside your written response. Not a generic workout plan. A clinical starting framework built around your history, injury background, and current capacity — the physical foundation for everything else you're working on.

Request the optional Movement History form when you email for access if you have any joint, injury, or movement history you want factored in.

Personalised · Not a template
What you'll understand differently

20 things this book changes.

01

The gap between "normal" and "optimal" on your blood tests — and why your ferritin of 25 is why you're exhausted

02

Why insulin rises a decade before blood sugar — and why your GP's "fine" glucose reading means nothing without fasting insulin

03

The pregnenolone steal — why chronic stress makes hormonal chaos inevitable and why you can't supplement your way out

04

Why waking at 2–4am is a blood sugar problem, not an anxiety problem

05

Why food sensitivities cause fatigue on Wednesday from pasta eaten on Monday

06

The Intervention Hierarchy — why supplements are Layer 7, not Layer 1, and why starting there is expensive guesswork

07

Why the HPA axis must be addressed before thyroid, and thyroid before sex hormones — always

08

Why LDL being "bad cholesterol" is marketing, not science

09

Why stress is the primary driver of gut symptoms — and why treating the gut without addressing stress produces short-term results at best

10

What GI-MAP stool analysis reveals that no elimination diet or probiotic protocol can identify

11

Why DUTCH hormone testing shows not just hormone levels but how they're being metabolised — which is where the clinical picture actually lives

12

The 120-day rule — why red blood cell markers take four months to change, and why expecting results in four weeks is a guarantee of disappointment

13

Why thyroid conversion problems don't appear on TSH — and why millions of people on thyroxine still feel terrible

14

The Liebig's Law shortest stave principle — why treating the wrong system first is why protocols fail even when the protocol itself is sound

15

Why organic acids testing reveals mitochondrial function, neurotransmitter metabolism, and nutrient deficiencies that blood tests miss entirely

16

Why exercise makes some people worse — and what that tells you about their HPA axis and metabolic state

17

The cortisol–melatonin seesaw — why poor sleep is often a cortisol problem disguised as a sleep problem

18

Why IBS is a description, not a diagnosis — and why the actual cause is almost always identifiable with the right tests

19

Why food sensitivity panels change over time — and why a sensitivity that was present two years ago may now be irrelevant

20

Why comprehensive functional testing almost always finds something meaningful — and why "everything is normal" is rarely the whole story

The full pathway

Start here. Go as far as you need.

The Starter Kit is the entry point to a complete clinical pathway. Every step is optional — many people find the written response gives them everything they need. Others use it as the launchpad for the full investigation.

1
Self-Directed Starter Kit
Book, checklist, 46 tools, four reviewed intake forms, Foundation Reset movement plan, personal written response
You are here
£127
2
Discovery Consultation
One-to-one with Stephen. Full 16-form intake. Health Status Report. Wellness Engine profiling. Test recommendations. Starter Kit holders pay £95 instead of £145.
£95 for kit holders
3
Resilient Gut System
Four-month gut-focused coaching programme. For those where gut is the primary pattern. Consultation fee credited toward programme cost.
£1,500
4
TDG Five-Test Programme
The full investigation. All five tests simultaneously. 900+ data points. Complete personalised protocol built entirely around your biology. Consultation fee credited.
£3,500
Two formats

PDF and HTML. Both included.

Screen · Recommended

HTML Clinical Edition

Open in Chrome. Clickable navigation, zoomable full-colour diagrams, instant search, fast loading. Designed to be used as a working clinical reference — not read once and filed. The format that makes the most of the content.

Print · Offline

PDF Edition

Fully designed, print-ready. Everything in the HTML edition in a format you can annotate, share, and read without a connection. A4, optimised for printing at home or a print shop. Also available as a physical paperback on Amazon for £19.99.

Who this is for

If any of these are familiar.

You have been told your tests are normal while feeling anything but.

You have spent money on supplements that haven't produced results.

You are considering functional testing and want to understand what it involves before committing.

You want to understand your own biology rather than following generic advice.

You already have blood results and want to know what they actually mean.

You have tried multiple approaches and want to know why nothing has stuck.

About the author

Stephen Duncan MSc FDN-P

Functional Diagnostic Nutrition Practitioner based in Edinburgh with 37 years of clinical experience in health, fitness, and functional medicine. His approach began at 18 as an athletics and boxing coach — where he observed early that the same programme produces radically different results in different people. That observation became the framework that defines his practice.

Co-founder of Omnos, an early functional lab data platform now integrated with Regenerus Labs. Runs the TDG five-test programme through Detective Health, integrating Metabolic Typing, Functional Diagnostic Nutrition, and blood chemistry interpretation using functional reference ranges.

"I spent years watching clients struggle with generic advice. Eat less, move more. Take this supplement. Try this diet. When it didn't work, they blamed themselves. But the problem wasn't their willpower — it was that nobody was looking at what was actually happening inside their bodies."

FDN-P MSc Coaching Studies & Applied Sports Science BSc Developmental Biology · Glasgow Advanced Metabolic Typing Advisor C.H.E.K. Certified MTHFR & Methylation 37 Years Practice
Get started today

One kit. A complete starting point.

Instant download. Both formats included. Platform access and intake forms activated on request. Foundation Reset delivered within 5 working days of returning your forms.

£127
Instant download · Gumroad secure checkout
Get the Starter Kit — £127
Questions before buying? hello@detective-health.com
Common questions

Before you buy.

Is this just a PDF download?
No. It is a book in two formats (PDF and HTML), a working checklist, three months of access to 46 clinical self-assessment tools, four intake forms reviewed personally by Stephen with a written response, and a personalised movement plan. The personal written response alone takes more time to produce than a standard consultation.
How do I access the platform and intake forms?
After purchase, email hello@detective-health.com with the subject line "Starter Kit Access." You'll receive the platform link and intake form access by return. Complete the four core forms at your own pace and return them — your written response follows within 5 working days.
Do I need to have had blood tests already?
No. The kit is valuable with or without prior testing. If you have blood results, the book and platform help you interpret them against functional reference ranges. If you don't, the written response will include recommendations on whether and what to test.
How does the consultation discount work?
If you purchase the Starter Kit and subsequently book a one-to-one discovery consultation with Stephen, you pay £95 instead of the standard £145. If you then proceed to the TDG Five-Test Programme or Resilient Gut System, the £145 consultation fee is credited toward the programme cost. Each step builds on the last.
Is there a physical version?
Yes — the book is available as a paperback on Amazon for £19.99. The physical edition does not include platform access, intake form review, or the Foundation Reset. The Starter Kit is the digital clinical edition designed to be used as a working tool, not just read once.
Is this suitable for people outside the UK?
Yes. The framework, tools, and written response are relevant regardless of location. If functional testing is recommended and you're outside the UK, Stephen works with international clients through Nordic Labs (Europe), Direct Labs (US), and other partners globally.