It’s 3pm on a Wednesday, and you’re staring at your computer screen trying to remember what you were just doing. You’ve had two coffees already, but instead of feeling energised, you’re jittery and somehow more exhausted. You forgot your colleague’s name mid-conversation this morning. And the thought of what to cook for dinner tonight feels overwhelmingly complicated.
Sound familiar?
If you’re nodding along, you’re not alone. I see this pattern constantly in my practice. Clients come to me frustrated because they’ve been told their blood tests are “normal,” they just need to manage their stress better, or perhaps they should try another type of coffee.
But here’s what I’ve learned after 12+ years of working with exhausted, foggy-brained clients: this isn’t about willpower, and it’s not all in your head. Brain fog and crushing fatigue are symptoms pointing to real, identifiable imbalances in your body. And once we find and address those root causes, most people start feeling genuinely better.
In this article, I’m walking you through the functional medicine approach to brain fog and fatigue. Not the “just rest more” advice you’ve heard a thousand times, but the actual mechanisms behind why you feel this way and the practical steps that address the underlying issues.
Why Brain Fog and Fatigue Happen: The Functional Medicine View
Not Just “Being Tired”
Let’s be clear about what we’re talking about. Normal tiredness is what you feel after a big day or a poor night’s sleep. It responds to rest. You bounce back.
Chronic fatigue and brain fog are different. They persist despite rest. They affect your ability to think clearly, remember things, and function at your normal capacity. You might experience:
- Mental cloudiness or difficulty concentrating
- Forgetting words, names, or why you walked into a room
- Needing the entire weekend just to recover from the work week
- Feeling tired but also weirdly wired
- Dragging yourself through activities that used to feel easy
This isn’t a character flaw. It’s your body telling you something is off.
The Root Causes I See Most Often
In functional medicine, we look for the underlying mechanisms driving your symptoms. Here are the most common culprits I identify in practice:
HPA Axis Dysregulation and Cortisol Patterns
Your HPA axis (hypothalamic-pituitary-adrenal axis) manages your stress response. When you’re under chronic stress, whether physical, emotional, or biochemical, this system can become dysregulated. Your cortisol pattern gets disrupted. You might have cortisol spiking when it should be low (hello, 2am wide awake sessions) or bottoming out when you need it most (that 3pm crash).
This isn’t about “adrenal fatigue” in the way it’s sometimes misrepresented online. Your adrenals aren’t broken. But the signalling system is struggling, and it affects everything from your energy levels to your ability to handle stress. Natural ways to support healthy cortisol patterns can make a real difference here.
Thyroid Dysfunction Hiding in Plain Sight
I can’t tell you how many clients come to me saying their thyroid has been tested and it’s “fine.” But when I look at their actual results, I see TSH at 3.5 (within lab range, but not optimal), low-normal free T3, or elevated thyroid antibodies that weren’t even tested.
Standard thyroid testing often misses subclinical hypothyroidism or conversion issues. Your thyroid hormones are absolutely crucial for energy production, cognitive function, and metabolism. Even slight dysfunction can cause significant symptoms. Understanding thyroid dysfunction is often a game-changer for people.
Blood Sugar Dysregulation
If you’re experiencing energy crashes, brain fog after meals, or needing to eat constantly to avoid feeling shaky, blood sugar dysregulation is likely part of the picture. When your blood sugar spikes and crashes throughout the day, your brain (which relies heavily on stable glucose) suffers. You end up in a cycle of fatigue, cravings, more crashes, and stress hormone release.
Nutrient Deficiencies
Your body needs specific nutrients to produce energy at a cellular level. The ones I test most frequently:
- Iron: Essential for oxygen transport and energy production
- B12: Critical for nerve function and red blood cell formation
- Magnesium: Involved in over 300 enzymatic reactions, including energy production
- Vitamin D: Impacts everything from immune function to mood regulation
These deficiencies are incredibly common, especially in people with digestive issues, restrictive diets, or high stress levels.
The Gut-Brain-Energy Connection
Your gut health directly impacts your energy and cognitive function. Inflammation from gut dysfunction triggers immune responses that affect your brain. Nutrient absorption suffers. Your gut bacteria influence neurotransmitter production. If you’re dealing with bloating, irregular bowel movements, or food sensitivities alongside fatigue and brain fog, your gut is absolutely part of the equation.
Mitochondrial Function Issues
Your mitochondria are the powerhouses of your cells, literally producing the energy (ATP) you run on. When mitochondrial function is compromised by oxidative stress, nutrient deficiencies, or toxin exposure, energy production drops. You feel it as persistent, crushing fatigue.
Key Point: These issues rarely exist in isolation. More often, I see a combination: thyroid function is slightly low, which worsens blood sugar regulation, which increases stress hormones, which disrupts sleep, which depletes nutrients, which further impairs thyroid function. It’s a compound effect, and addressing one piece often starts improving the others.
Why Your Tests Come Back “Normal”
Here’s something that frustrates my clients endlessly: they feel terrible, but their doctor says everything looks fine.
This happens because standard medical testing uses pathological ranges, not functional ranges. Labs are designed to catch disease, not early dysfunction. Your TSH might be 3.8 (within the 0.5-4.5 range), but functional practitioners recognise that optimal is closer to 1-2 for most people.
Your iron studies might show ferritin at 30 (technically not deficient), but you need it above 70-100 to feel good and support energy production.
This is where functional medicine shines. We’re looking for optimal function, not just the absence of diagnosed disease.
What I Actually Do When Clients Come to Me With These Symptoms
The Initial Assessment
When someone books a consultation for fatigue and brain fog, I’m listening for specific patterns:
- When did this start? Was there a trigger (illness, major stress, life change, medication)?
- What does your day look like? Sleep patterns, meal timing, work stress, movement
- What have you already tried? This tells me what hasn’t worked and helps avoid repeating unsuccessful approaches
- What else is happening? Digestive symptoms, menstrual changes, mood shifts, sleep quality
I’m building a timeline and connecting dots. Often, clients will mention something in passing (“Oh, I had glandular fever two years ago”) that’s highly relevant to their current state.
Testing That Provides Useful Information
I’m not a fan of testing for testing’s sake. It’s expensive, and random testing without clinical reasoning rarely helps. But targeted testing is invaluable.
When I recommend functional testing:
- You’ve tried foundational strategies and aren’t improving
- Your symptoms are severe or getting worse
- There are multiple complex symptoms suggesting systemic issues
- You want to be precise rather than guessing
Common tests I use:
- Comprehensive thyroid panels (TSH, free T3, free T4, reverse T3, thyroid antibodies)
- Cortisol patterns (often via salivary testing throughout the day)
- Full iron studies (not just haemoglobin)
- B12, active B12, folate, homocysteine
- Vitamin D
- Comprehensive metabolic panels
- If gut symptoms are present: stool testing to assess microbiome health
Prioritising: We Can’t Fix Everything at Once
One of the biggest mistakes people make (and I’ve been guilty of this myself) is trying to overhaul everything simultaneously. New diet, 10 supplements, meditation practice, exercise routine, all starting Monday.
It’s overwhelming, unsustainable, and makes it impossible to know what’s actually helping.
Instead, I work with clients to prioritise based on:
- What’s likely causing the most impact
- What’s achievable given their current capacity
- What will give them some relief quickly to build momentum
Sometimes we start with blood sugar stabilisation because it gives relatively fast improvements. Other times, addressing sleep is the clear priority. It’s individual.
Practical Strategies That Actually Move the Needle
Let’s get into the specifics. These are the interventions I use most frequently with clients experiencing brain fog and fatigue.
Blood Sugar Stabilisation: Often the Fastest Win
Why this matters: Your brain is an energy hog, consuming about 20% of your body’s glucose. When blood sugar is unstable, your brain suffers first. You get foggy, irritable, and exhausted.
What I recommend:
Breakfast composition is crucial. I see so many people starting their day with toast, cereal, or just coffee. This sets up a blood sugar spike and crash before 10am. Instead:
- Aim for 25-30g protein at breakfast
- Include healthy fats (avocado, nuts, olive oil, eggs)
- Keep processed carbs minimal
- Examples: vegetable omelette with avocado, Greek yoghurt with nuts and berries, leftover dinner protein with greens
Protein targets throughout the day. Most of my clients aren’t eating nearly enough protein. I typically recommend 1.2-1.6g per kg of body weight, spread across meals. This stabilises blood sugar and provides amino acids for neurotransmitter production.
The snack trap. Constant snacking often indicates poor meal composition. If your meals are protein-rich and balanced, you shouldn’t need to eat every two hours. Frequent eating can actually worsen insulin sensitivity over time.
Supporting Adrenal Function and Cortisol Patterns
When cortisol patterns are disrupted, you feel tired but wired, struggle to fall asleep despite exhaustion, or wake frequently during the night.
Adaptogens with actual evidence:
I use adaptogens strategically, not as a blanket approach. The ones I find most useful:
- Rhodiola rosea: Particularly good for mental fatigue and stress resilience
- Ashwagandha: Helps reduce cortisol in people with chronic stress, improves sleep quality
- Holy basil: Supports stress response, can help with anxiety-related fatigue
But here’s the thing: adaptogens support your stress response; they don’t remove stress. If you’re working 70-hour weeks, getting 5 hours of sleep, and living on coffee, no herb is going to fix that. We need to address the lifestyle factors too.
Sleep hygiene that goes beyond “no screens”:
Yes, limiting blue light helps. But I’m more interested in:
- Consistent sleep and wake times (even on weekends)
- Creating a proper wind-down routine starting 60-90 minutes before bed
- Managing light exposure: bright light in the morning, dim lighting in the evening
- Magnesium glycinate before bed (200-400mg) for many clients
- Blood sugar stability so you’re not waking due to glucose crashes
Supporting adrenal health requires consistency more than perfection.
Thyroid Support
If testing reveals thyroid dysfunction, the approach depends on severity.
Nutritional support for thyroid function:
- Selenium: Required for T4 to T3 conversion (200mcg daily)
- Zinc: Important for thyroid hormone production (15-30mg daily)
- Iodine: But only if deficient, and carefully (excess can worsen autoimmune thyroid conditions)
- Iron: Essential for thyroid peroxidase enzyme function
When medication is needed: Sometimes natural support isn’t enough. If your TSH is significantly elevated or you have overt hypothyroidism, thyroid medication may be necessary. I work collaboratively with GPs when medication is appropriate, and we support optimal function alongside it.
Key Point: Natural approaches work best for mild dysfunction or as support alongside medication. We’re not anti-medication; we’re pro-getting you feeling better, whatever that requires.
The Gut-Brain Connection
Gut dysfunction creates inflammation that travels to your brain. It impairs nutrient absorption, worsening deficiencies that contribute to fatigue. It affects neurotransmitter production, impacting mood and cognition.
Practical gut healing steps:
I’ve written extensively about healing leaky gut naturally, but the basics include:
- Identifying and removing trigger foods (often gluten, dairy, or high-FODMAP foods temporarily)
- Supporting digestive function with appropriate enzymes or HCl if needed
- Rebuilding gut lining with L-glutamine, zinc carnosine, and slippery elm
- Rebalancing microbiome with targeted probiotics or fermented foods
- Managing stress (it directly impacts gut barrier function)
Mitochondrial Support
Your mitochondria need specific nutrients to function optimally and produce energy.
Key nutrients I use:
- CoQ10: Essential for electron transport chain function (100-200mg daily)
- Magnesium: Involved in ATP production (300-400mg daily, as glycinate or threonate)
- B vitamins: B1, B2, B3, B5 all support energy production (often via a quality B complex)
- Alpha-lipoic acid: Powerful antioxidant that supports mitochondrial health
Why gentle movement helps (even when you’re exhausted):
This seems counterintuitive. You’re tired, why would you exercise?
But gentle, appropriate movement actually improves mitochondrial function. It stimulates mitochondrial biogenesis (making new mitochondria) and improves efficiency. The key is gentle: walking, yoga, light swimming. Not pushing through intense workouts when you’re depleted.
What Doesn’t Work: Common Mistakes I See
Let me save you some time, money, and frustration by highlighting what I see fail repeatedly:
Pushing Through With More Caffeine
I get it. You’re exhausted and you need to function. But relying on increasing caffeine consumption creates a vicious cycle. Caffeine spikes cortisol, which depletes you further in the long run. It disrupts sleep. It can worsen anxiety. And eventually, you develop tolerance and need more for the same effect.
I’m not anti-coffee (I enjoy it myself), but using it to override your body’s signals of exhaustion is like ignoring your car’s check engine light and just turning up the radio.
Random Supplementation Without Testing
“I read online that rhodiola helps fatigue, so I bought some. And magnesium. And a B complex. And some adrenal support formula. And iron, just in case.”
Supplements can be powerful tools, but without understanding your specific deficiencies and imbalances, you’re guessing. It’s expensive guesswork that rarely works optimally and can sometimes backfire (excess iron if you’re not deficient can be pro-inflammatory, for example).
All-or-Nothing Approaches
Deciding you’re going to eat perfectly clean, meditate for 30 minutes daily, exercise 5 times a week, and go to bed by 9pm starting immediately is setting yourself up to fail.
Small, sustainable changes compound over time. Perfectionism often backfires, creating stress about not doing things “right,” which worsens the underlying problem.
Ignoring Sleep Debt
You cannot supplement your way out of chronic sleep deprivation. If you’re consistently getting 5-6 hours when you need 7-8, everything else becomes harder. Sleep is when your body repairs, consolidates memories, balances hormones, and clears metabolic waste from your brain.
It’s foundational. Not negotiable.
Expecting Quick Fixes
I wish I could tell you that you’ll feel completely better in two weeks. Sometimes people do experience significant improvements quickly, especially with blood sugar stabilisation. But for most people with chronic fatigue and brain fog, meaningful, lasting improvement takes 2-3 months of consistent work.
Your body didn’t get into this state overnight. It won’t reverse overnight either.
Building a Sustainable Recovery Plan
Here’s how I typically structure recovery with clients:
Phase 1: Stabilise and Support (Weeks 1-4)
Goals: Reduce immediate symptoms, stabilise blood sugar, improve sleep basics, gather information
Focus areas:
- Adjust breakfast and meal composition for blood sugar stability
- Establish consistent sleep schedule
- Reduce obvious stressors where possible
- Begin foundation supplements if clearly indicated (vitamin D if deficient, magnesium for most people)
- Consider initial testing to guide next phase
What you might notice: Less severe energy crashes, possibly sleeping slightly better, reduction in cravings, a bit more mental clarity
Phase 2: Address Underlying Causes (Weeks 4-12)
Goals: Target specific imbalances identified through testing and assessment, support healing processes
Focus areas:
- Implement targeted nutritional support based on test results
- Begin gut healing protocol if relevant
- Address hormonal imbalances (thyroid, cortisol, sex hormones)
- Refine diet based on individual response
- Add targeted supplements as indicated
- Adjust sleep and stress management practices
What you might notice: Sustained energy improvements, better cognitive function, improved stress resilience, digestive symptoms resolving
Phase 3: Maintain and Optimise (3+ Months)
Goals: Lock in improvements, fine-tune approach, prevent relapse
Focus areas:
- Determine which interventions need to continue long-term vs. which were temporary
- Retest key markers to confirm improvements
- Build resilience and establish sustainable practices
- Recognise early warning signs of slipping backwards
- Adjust plan seasonally or as life circumstances change
Key Point: Recovery isn’t linear. You’ll have better weeks and harder weeks. That’s normal. We’re looking for an overall upward trend, not perfection.
When to Get Professional Support
Some situations absolutely warrant working with a practitioner rather than trying to manage everything yourself.
Red Flags That Need Medical Investigation
See your GP urgently if you experience:
- Sudden onset of severe fatigue (rather than gradual)
- Unexplained weight loss or gain
- Fever or night sweats
- Shortness of breath or chest pain
- Severe headaches or neurological symptoms
- Thoughts of self-harm
These could indicate serious medical conditions that need immediate attention.
When Functional Medicine Testing Is Worth It
Consider working with a naturopath and investing in functional testing if:
- You’ve tried foundational strategies consistently for 2-3 months without improvement
- Your symptoms are significantly impacting your quality of life or ability to work
- You have multiple complex symptoms suggesting systemic issues
- You’ve been told everything is “normal” but you clearly don’t feel normal
- You want a precise, individualised approach rather than trial and error
How I Work With Clients Remotely
I provide online consultations for clients throughout Australia. Here’s the typical process:
Initial comprehensive assessment (75-90 minutes): We go through your health history in detail, discuss symptoms, review any existing test results, and develop an initial plan.
Testing coordination: I organise any necessary functional testing through laboratories that service all of Australia. Most testing can be done via local pathology collection centres or at-home kits.
Follow-up consultations: We typically meet every 2-4 weeks initially to monitor progress, adjust the plan, and provide ongoing support.
Between-session support: You have access to message me with questions, and I provide written protocols so you always know what you’re doing and why.
Learn more about how I work with clients
What to Expect From Naturopathic Support
Realistic outcomes:
Most clients with fatigue and brain fog see noticeable improvement within 6-12 weeks of targeted intervention. This doesn’t mean feeling 100% better immediately, but rather:
- More sustained energy throughout the day
- Improved mental clarity and ability to concentrate
- Better sleep quality
- Reduced reliance on caffeine
- Feeling more like yourself
Timeline for improvement:
- Weeks 1-2: Often minimal change (we’re still gathering information and making adjustments)
- Weeks 3-6: First noticeable improvements, particularly with blood sugar and sleep
- Weeks 6-12: More substantial improvements in energy and cognition
- 3+ months: Sustained improvements, building resilience
Collaborative approach:
I work alongside your GP, not instead of them. If you’re on medications, we coordinate. If testing reveals something that needs medical management, I refer appropriately. The goal is getting you better, whatever that requires.
Understanding chronic fatigue from a naturopathic perspective
The Path Forward
If you’ve made it this far, you’re probably recognising yourself in some of these patterns. Maybe you’ve been pushing through brain fog for months or years, wondering if this is just how life is now.
It doesn’t have to be.
Brain fog and crushing fatigue are symptoms pointing to underlying imbalances, not character flaws or inevitable parts of getting older. When we identify and address the root causes, whether that’s thyroid dysfunction, blood sugar dysregulation, nutrient deficiencies, gut issues, or a combination, most people experience meaningful improvement.
The functional medicine difference is treating the whole system, not just suppressing symptoms. It’s looking for why you’re exhausted and foggy, not just giving you something to temporarily mask it.
Does it take some work? Yes. Does it require patience and consistency? Absolutely. But the alternative is continuing to feel like this, and that’s not really an option, is it?
If you’re ready for personalised support that gets to the root of what’s actually going on, I’d love to work with you. Book a consultation and we’ll start building your plan.
About Sarah Mitchell
I’m Sarah Mitchell, a degree-qualified naturopath (BHSc Naturopathy) and member of ATMS and ANTA. I’ve spent 12+ years helping clients across Australia cut through conflicting health advice and build practical plans that actually fit into real life.
My approach is calm, realistic, and supportive. Clear steps, consistent guidance, and a focus on sustainable habits you can stick with. Because what’s the point of a perfect plan you can’t maintain?
I provide online consultations Australia-wide, working with clients to address fatigue, hormonal issues, digestive concerns, and the complex, interconnected problems that standard approaches often miss.
Ready to feel better? Book your initial consultation here
