For FDN practitioners and students · UK practice
Blood chemistry isn’t one of the FDN lab tests, and when I mention to other FDN practitioners that I run it routinely, the usual reply is surprise. In much of the US it is genuinely hard for a non-medical practitioner to order. In the UK it is straightforward, if you do it properly. Here is exactly how I do it.
The FDN tests look at hormones, gut, organic acids and food reactions. They don’t cover the markers a GP, a haematologist or an endocrinologist would recognise: full blood count, iron studies and ferritin, thyroid, HbA1c, lipids, kidney and liver function. Those are also the most thoroughly validated tests in the whole picture, with population reference ranges and clinical guidance behind them.
Two practical reasons they matter. First, they anchor the functional findings: a ferritin or a thyroid result changes how I read a tired client’s DUTCH. Second, they are a safety net. Occasionally a blood panel shows something that needs a doctor, and I would rather find it than miss it because it wasn’t on the menu.
In the US, whether a practitioner without a medical licence can order a blood test depends on the state. New York, for example, only allows laboratories to offer tests directly to consumers where an FDA-approved over-the-counter kit exists for the same purpose. Practitioner platforms restrict what can be ordered for people living in New York, New Jersey and Rhode Island. That is the background to FDN’s own sessions on “accessing labs without a medical licence”.
The UK doesn’t have a state-by-state patchwork. Private laboratories supply practitioner panels, and trained phlebotomists will draw the sample at the client’s home. What limits a UK practitioner is not ordering the test. It is what you then say about the result.
I use Regenerus panels: a 57-marker panel, a Functional Platinum panel that adds inflammatory markers, fasting insulin and homocysteine, and a larger panel on request. The right one depends on the question, not the marker count. Prices and contents are on the blood test options page.
The lab posts the collection kit directly to the client with instructions: usually a fasted morning draw.
The client books a qualified mobile phlebotomist, who visits them at home or at a clinic. I use an independent network and link it from my blood draw page. Home visits are the difference between testing happening and not happening for a lot of my clients.
The sample is posted to the lab. Results return to me, usually within one to two weeks.
Every marker is read against the laboratory’s own reference range first, then against a tighter threshold only where there is a stated source for one. Ferritin is the clearest example: NICE guidance treats a ferritin below 30 µg/L as confirming iron deficiency, even though many lab ranges start lower.
A result outside the laboratory range that could point to disease is not mine to manage. The client takes it to their GP, with a short note from me if that helps.
“Nutritionist” is not a protected title in the UK; “dietitian” is. That makes it easy to start, and it is exactly why the line has to be held by the practitioner.
The reasoning I use for reading bloods alongside the FDN tests — which markers change the interpretation of which functional finding, and when a result goes to the GP — is written down in the TDG Clinical Manual. Module 01 is free. If you’re weighing up the FDN training itself, my review of the certification and FDN in the UK cover it.
Not an affiliate link — this one is mine
Leave your details and say which is closest to you. I send occasional notes for UK practitioners — labs, scope, corrections — and I read every question that comes in. Module 01 of the manual is on the next page, free.
FDN training link, if you want to look at the programme itself: FDN’s free sample modules. Affiliate link: I am paid a commission if you later enrol; nothing on the free modules.