Why I Don’t Sell Tests and Supplements

Why I don’t sell tests and supplements.

I recently had it suggested that by offering supplements and nutrition-related tests—like blood tests, gut health tests, or hormone panels—I could increase my credibility and income as a Nutritionist.  

It’s a fair suggestion-many in the field are doing exactly that.

But for me, it would do the exact opposite of what I aim for in my practice: it would compromise my integrity, blur my professional boundaries, and potentially mislead the very people I aim to help.

Why Tests Like Hair Analysis, Food Sensitivity and Gut Microbiome Aren’t Valid 

The market is flooded with private tests — you can literally check everything from head to toe. When people struggle with food, weight, health symptoms, menopause, energy, or mood, they often seek answers. Unfortunately, that makes them easy targets for those selling these tests.

Of course, they will do anything to make themselves feel better and improve their quality of life and marketing plays on this vulnerability. These tests are often sold as simple fixes to complex issues. The appeal of a neat diagnosis or a list of foods to cut out can feel easier than dealing with the messy, nuanced reality of human health. But these “black-and-white” solutions are rarely accurate — and rarely helpful.

Let’s explore a few of the most common tests I see marketed or get asked about and explain the scientific validity (or lack thereof). Of course, this is just a sample of the many tests out there, but it helps you to understand that many of these tests are not going to be the answer.

Hair Mineral analysis 

Hair mineral analysis claims to test your hair for vitamin and mineral deficiencies and “imbalances”.   

But here’s the problem, there’s no reliable evidence that these are an accurate way to decipher the levels of vitamins and minerals in your body tissue and in fact you can have low levels in your hair without deficiency and vice versa.   

This study found that hair samples taken and then sent to different labs came back with wildly different results and even the same sample sent twice to the same lab came back with different readings. 

Another study concluded from its findings:  

“Hair mineral analysis from these laboratories was unreliable, and we recommend that health care practitioners refrain from using such analyses to assess individual nutritional status or suspected environmental exposures,”  

Why iso much variation?  Because there is no regulation and validation on the testing methods and there are no agreed ‘normal’ and so labs can define their own.  Each testing company has its own protocols, which may or may not lead to internally consistent results at a given lab, but there’s still no evidence-based definition of “normal.” 

My Advice: If you are worried about nutrient deficiencies, ask your GP for a blood test — it’s free and clinically valid. 

IgG Food intolerance tests

These are often marketed as a way to identify food intolerances. But there’s no good-quality evidence that they work. 

In fact the advertising standards authority have ruled that companies cannot claim to diagnose food intolerances with these tests due to this lack of evidence and the concern of the damage these false claims could cause. 

Everyone produces IgG’s in response to eating food, it’s a normal immune response.  So, when a test tells you your “intolerant” to half your diet, it’s more likely reflecting what you’ve eaten recently than what’s harming you. 

These tests can: 

• Cause unnecessary food fear 

• Lead to over-restriction and nutritional deficiencies 

• Delay appropriate medical assessment and diagnosis 

My advice:  If you suspect an intolerance or allergy then please seek support from your GP or a Registered Dietitian. 

Why I don’t sell tests and supplements

At Home Gut Microbiome Tests 

These tests look ‘sciencey’ but are not really showing anything of clinical meaning and they can’t be used to diagnose or treat medical conditions.   

We still don’t have a clear definition of a ‘normal gut microbiome’ is.  So how can we tell if yours is ‘abnormal’ and what should we do about it? 

Clinicians will use symptoms and clinical assessment to diagnose and treat gut disorders – not gut microbiome tests, so save your money on these.  They often cause anxiety – and that alone is something that can worsen your gut symptoms! 

Blood tests for menopause 

There is often no need for blood tests to diagnose menopause or perimenopause.   

The British menopause society and NICE advise that in otherwise healthy women over the age of 45 years (not on hormonal contraception) can be diagnosed on the symptoms alone – no blood test needed.   

In other cases, blood tests might be useful — but only when part of a clinical conversation, not sold online in isolation. 

Perimenopause and menopause symptoms can overlap with other conditions and simply getting a random blood test from an online nutritionist can mean you not getting the right investigations, diagnosis and treatment.   

My advice:  If you are struggling with symptoms of menopause seek advice from a qualified medical professional (you can ask for a menopause specialist GP at lots of GP surgeries). 

Why I don’t sell tests and supplements

The Risks of Selling or Recommending Supplements for Profit 

I am proud to be an evidenced based healthcare professional – my core values are trust and integrity.  

 If I were to sell you supplements, this creates a conflict of interest- how do you know if my recommendation was based on my professional assessment and truly in your best interests- or just good for my bank balance? 

Many clients come to me after seeing practitioners who start with: 

• A long list of expensive private tests 

• A shopping list of supplements (sold directly by the practitioner) 

It’s easy to see how this creates confusion — and conflict of interest. 

What would be left of their practice without these tests to base inaccurate advice of- do they really know how to assess you, offer evidenced based advice and meet your individual needs? 

The truth is most supplements are not actually required if people are eating a mostly healthy balanced diet.  There is a time and a place for supplements but when they are useful, it’s mainly in specific situations, for specific people, based on clinical assessment. 

And just because something is natural, doesn’t mean it’s safe and so any supplements should be discussed with your doctor before starting to check they are appropriate for you.  This is another good reason not to just offer them up willy nilly without the correct training.  For example: 

• Black cohosh has been linked to liver problems 

• Sage leaf can interact with anticonvulsants or affect blood sugar 

• St John’s Wort can interfere with medications like warfarin 

In my clinic: 

✔️ Supplements are only suggested when supported by assessment or current evidence base
✔️ Clients are encouraged to buy independently  
✔️ I refer them to their GPs and for NHS blood tests where needed (these are free and assessed by qualified medical professionals who can treat you appropriately if required!) 

  

Why I don’t sell tests and supplements

Evidence-Based Nutrition: What This Means in Practice 

Evidence-Based Practice (EBP) means making decisions based on the best available, current, valid and relevant evidence– not trends or product sales. 

Benefits of evidenced based practice: 

• Improve the quality of healthcare 

• Improve client outcomes 

• Reduce healthcare costs and harm  

• Supports consistent, high-quality standards 

It is also important to know that Nutritionist is not a protected title status in the UK.  Anyone can call themselves one, even if they have not taken appropriate scientific training. 

Nutritional therapists are often using alternative medicine strategies that are often not based in science and although their approach can suit some, it is always worth checking that you are getting the right support for your symptoms or concerns. 

That’s why I am proud to be a Registered Nutritionist with the Association for Nutrition – a register of competent, qualified nutrition professionals who meet our rigorously applied standards for scientifically sound evidence-based nutrition and its use in practice and the only register recognised by the NHS.   

There’s a clear distinction between credible nutrition advice and health marketing trends, but unfortunately, ‘wellness advice’ often blurs the line between the two. As a regulated professional, if I were to offer advice that isn’t evidence-based, I could lose my registration. That level of accountability means you can trust that what I share is rooted in science — not driven by sales — making it nutrition advice you can rely on.

Why I don’t sell tests and supplements

How Unvalidated Testing Can harm our Relationship with Food 

So many of my clients come to me struggling with: 

• Food anxiety 

• A history of dieting and restriction 

• Guilt or confusion about eating 

Vague and alarming test results can make things worse. They: 

• Fuel food fear  

• Encourage disordered or restrictive eating 

• Delay proper diagnosis of real medical issues (e.g. coeliac, IBS, thyroid conditions) 

Building Trust Through Transparency  

Impartiality matters in a wellness landscape full of upselling and marketing.  

When you choose a Nutritionist, you want someone: 

• Scientifically trained
• Impartial
• Honest when they don’t know something
• How I foster trust with clients:
  • personalised assessments
  • Clear, open communication
  • No upselling or commission-based products
  • Seeking answers from trusted sources if I don’t have them immediately

What Do I Offer Instead 

• 1:1 nutritional support grounded in science
• Collaborative goal setting
• Referral to NHS testing and treatment when appropriate
• Behavioural support for your relationship with food
• A compassionate, judgment-free approach (I’m trained as a Compassionate Mind facilitator)

Final Thoughts: Keeping Clients at the Centre 

My approach is built around empowering clients — not selling to them. 

Ask yourself: 

Do I want a Nutritionist who’s selling me a quick fix solution, or one who’s helping me understand my needs with honesty and care? 

Next time you’re offered a private test or supplement, ask: 

• Would my GP use this test?
• If not, why not?
• Is this too good to be true?

If this blog has shifted your view on private testing and supplement sales, I’d love to hear from you. 

And if you’re looking for support that’s grounded in science, ethics, and genuine care — feel free to get in touch. 

Why I don’t sell tests and supplements