Let’s talk about functional testing. Is it a massive waste of money or an absolute necessity on your thyroid healing journey?

The answer is, just like with many other things, it depends!

Firstly, what are functional tests?

These are tests we use to help us map out your thyroid terrain, meaning what is currently driving your symptoms and condition, as well as your unique root causes, which are things that might have contributed to your thyroid condition and are still present.

These tests are generally accessed through functional medicine practitioners like myself and are not routinely used in mainstream medicine, which tends to focus on diagnosing and managing specific conditions and symptoms rather than investigating every potential underlying factor.

Yay or nay? My stance on functional testing

Overall, yay. But there’s a big BUT.

Functional tests can be incredibly helpful, but for most people, they’re not needed as a starting point. One of my biggest issues with the root cause approach is excessive testing that gives us an avalanche of information without fundamentally changing our approach or healing protocols.

With Hashimoto’s and hypothyroidism, we already know, to a large extent, which underlying factors are commonly associated with these conditions. Many of the root causes and imbalances overlap. This is why rebuilding your thyroid terrain and working on deep foundations, like we do in the first one to two months of BLOOM, can produce significant results for many people.

Once the foundations are in place, we can assess your symptoms and thyroid terrain again and decide whether further investigations are needed.

You might be wondering what sort of tests we could do. There are so many, from hair analysis, toxic exposure testing, viral screens, food intolerance testing, gut microbiome analysis and hormonal panels, all the way to high-tech epigenetic testing.

But the reality is that, in my highly specialised, thyroid-focused practice, I tend to use the same tests again and again.

There are three tests I run regularly because they can provide actionable insights, help us tailor protocols and guide our next steps.

My three favourite functional tests, and one I never do

1. DUTCH test

This is probably the test I use most often in BLOOM for anyone wanting to understand their hormones better, especially if they’re struggling with PCOS, entering perimenopause, considering HRT or trying to conceive.

It’s particularly useful for exploring how your body processes and metabolises oestrogen, providing information about hormone metabolites that we cannot obtain from a standard blood test alone.

Functional oestrogen dominance can be pro-inflammatory and may affect thyroid health. This test can help assess hormone metabolism and identify areas worth investigating further.

DUTCH testing also provides insight into cortisol patterns, which, as I’m sure you already know, can play a significant role in the Hashimoto’s healing journey.

2. Saliva stress test

A saliva cortisol test with five collection points throughout the day shows your daily cortisol rhythm, providing a fuller picture than the single snapshot offered by a blood cortisol test.

It’s a great option for those who don’t want or need a DUTCH test but are looking to understand how their stress response might be affecting their body.

Cortisol testing can be incredibly helpful. And contrary to what you might hear, cortisol isn’t always high when we’re feeling stressed. Sometimes, the pattern looks quite different.

Testing can help us understand what’s happening and tailor our approach accordingly, rather than guessing.

3. Stool test

A functional stool test can provide around 25 pages of insights into your microbiome and gut health, including markers related to inflammation, digestion and aspects of immune function.

Depending on the test, it may also identify specific organisms or imbalances that could be relevant to your symptoms.

What we have to remember, though, is that we’re not always as unique as we’ve been led to believe. Many gut imbalances overlap, so not everyone absolutely needs this test.

Generally speaking, it’s particularly useful for anyone with persistent gut symptoms. If we’re not seeing the improvements we’d expect after the first one to two months of my Thyroid Terrain protocol, I may recommend stool testing so we can look under the hood.

Gut health is also an important consideration in Hashimoto’s, even if you don’t experience obvious digestive symptoms. That’s why we dedicate time to gut health and restoration work during month four of BLOOM.

The test I never do: basic food intolerance IgG testing

Basic food intolerance IgG tests are a hard no from me. They’re not a reliable way to diagnose food intolerances, and the results can lead people to eliminate perfectly good foods unnecessarily.

IgG antibodies to foods often reflect exposure to those foods rather than proving that they are causing symptoms. Please don’t fall into the trap of cutting out half your diet based on a test that doesn’t tell you what you think it does!

So, which functional test do you actually need?

I hope you’ve found this deep dive useful. Which test do you think might be relevant to you?

If you’re not sure, one of the benefits of working together inside BLOOM is that you don’t have to figure it all out yourself. I review your health history and symptoms and help determine what might be most useful in your individual case, including whether further testing is needed at all.

Functional testing can be a valuable tool, but it isn’t the starting point for everyone. The real change begins with deep foundational work on your nutrition, lifestyle and nervous system.

Before spending hundreds of pounds on tests, make sure you have a clear idea of what you’re looking for, why you’re testing, and how the results would change your next steps.

If you’re ready for personalised support with your Hashimoto’s or hypothyroidism, BLOOM is my signature thyroid restoration programme, designed to help you explore the factors affecting your health and build a more sustainable approach to feeling better.

You can explore BLOOM, find out more about the programme and join the waiting list for the next cohort through my website.

Aggie x