About Us

Leesa | Naturopath & Master Herbalist in Perth

The Heart Behind the Clinic

I don't just prescribe medicine; I grow it.

 

My journey into health didn’t start in a classroom—it started in the soil. Before becoming a Herbal Naturopath, I spent 15 years owning and operating an organic nursery, where I learned the language of plants first hand.

Today, as the founder of Oak Tree Herbal Clinic, I merge that deep horticultural wisdom with clinical science. Many of the remedies I recommend are the very ones I have raised from seed in our Western Australian climate, ensuring every bottle is a pure, handcrafted expression of "Seed-to-Bottle" medicine.


Seed to Bottle: A Life Immersed in Herbs

In the harsh summers and mild winters of our Western Australian climate, I cultivate a specialized medicinal garden. I grow, harvest, and manufacture botanical remedies from the resilient species that thrive in our local soil, turning them into potent herbal tinctures and flower essences.

I am constantly researching and trialing new species to expand my clinical dispensary. To me, working with medicinal herbs isn't just a career—it is my life’s work.

I speak to my plants every day, ensuring that every bottle produced at Oak Tree Herbal Clinic carries the pure, vibrant energy of the earth. When you work with me, you aren't just getting a standard supplement; you are receiving a handcrafted remedy born from 15 years of organic horticultural wisdom and clinical naturopathic precision.


Clinical Detective meets Mother’s Heart

Beyond the garden and the lab, my world revolves around my family. As a single mother of four grown boys and a proud grandmother, I understand the complexities of modern family life and the deep drive to protect our children's wellbeing. I know how vital a resilient nervous system is for a happy home.

I combine this "Mother’s Intuition" with high-level science—specializing in MTHFR support, Functional Genomics, and ADHD. I help families stop the guesswork by merging the latest DNA technology with the ancient healing power of the organic botanical medicine I grow by hand.

 

My Mission: Decoding the Brain-Body Connection

I don’t believe in "one-size-fits-all" health. Whether you are navigating an ADHD diagnosis, struggling with MTHFR-related burnout, or feeling "wired but tired," your symptoms are not a mystery—they are biological data points.

My work focuses on Functional Genomics and Nervous System Regulation that standard medicine often overlooks. I specialize in identifying the "first domino"—the primary biochemical or energetic imbalance that, when corrected, allows the rest of your health to fall back into place.


Why I Focus on MTHFR & Methylation

Early in my clinical practice, I realized many clients were doing "all the right things" but weren't getting results. This led me deep into the world of Methylation, Nutrigenomics, and Biochemistry.

I saw how a single genetic variant like MTHFR or COMT could fundamentally change how a person processes stress, clears toxins, and produces neurotransmitters like Dopamine and Serotonin. By specializing in these markers as a Methylation practitioner, I help my clients stop fighting their biology and start supporting it.

 

A Multidimensional Clinical Approach

I blend "High-Tech" diagnostics with "High-Touch" traditional wisdom. In my Perth Naturopathic clinic, we utilize:

  • Functional Lab Testing: Including DNA analysis, HTMA (Hair Tissue Mineral Analysis), and Microbiome mapping.
  • Bio-energetic Technology: Using the AVATAR system to listen to the body’s energetic signals in real-time.
  • Biochemical Precision: Applying targeted herbs and nutrients to bypass genetic "glitches" and restore systemic balance.


Why I Do What I Do

I believe that the best medicine is found where the laboratory meets the garden. I am here to help you and your family find your "root cause" and provide the handcrafted, evidence-based support your body needs to thrive.

 

Leesa Caldwell

Master Herbalist & Clinical Naturopath,

B.Nat, B.WHM, Adv.Dip.Nat, Adv.Dip.WHM, Adv.Dip.Nut.Med, Dip.Skin Form. 

Frequently Asked Questions

How accurate is Hair Tissue Mineral Analysis (HTMA)?

HTMA is a highly reliable, standardized functional test when processed by an accredited pathology laboratory. While blood tests measure nutrients circulating in your bloodstream at a single moment, hair tissue provides a stable, 3- to 4-month average of cellular mineral storage and heavy metal accumulation. Research shows that hair tissue is an exceptional medium
for monitoring long-term mineral balances, metabolic patterns, and environmental toxic load.

Can I do an HTMA test if my hair is coloured or dyed?

Yes, you can still complete an HTMA test if you dye your hair, but a few guidelines ensure accurate results:

  • Untreated Hair is Ideal: The best sample is taken from new growth at the nape of the neck (the first 3–4 cm closest to he scalp).
  • Wait Between Treatments: We recommend waiting 6 to 8 weeks (or roughly 6–8 washings) after bleach, dye, or a perm before collecting your sample.
  • Alternative Sample Options: If your head hair is heavily bleached or chemically treated from root to tip, we can easily utilize untreated beard hair or pubic hair as an accurate alternative.

How much hair is required for the sample, and will itleave a noticeable spot?

We only need about 125 milligrams of hair, which is roughly equivalent to a heaped teaspoon. Samples are taken in tiny, thin snips from multiple discreet locations near the base of the skull at the nape of the neck. Because the cuts are small and hidden under your top layers of hair, it is completely undetectable once your hair is down.

Is HTMA testing suitable for young children or sensory-sensitive individuals?

Absolutely—HTMA is one of the most gentle, non-invasive functional tests available. Because there are no needles, blood draws, or fasting required, it is ideal for toddlers, young children, and sensory-sensitive clients.

If you visit our Kingsley, WA clinic, we can handle the sample collection quickly and gently for you. Alternatively, if you are a Telehealth client or prefer to collect the sample at home, we will send you an email with clear, step-by-step instructions.

What is the difference between a blood test and a hair mineral test?

Blood serum is tightly regulated by the body to maintain homeostatic balance (for example, keeping blood calcium levels stable to protect heart function). If tissue mineral levels drop, the body will pull calcium from bones and tissue into the blood to compensate—making blood work
appear "normal" even during cellular depletion. HTMA measures the minerals actually stored in your cells and tissues over time, revealing chronic imbalances that standard blood tests frequently miss.

How long does it take to get my HTMA results back?

Once your sample arrives at our laboratory, analysis typically takes 2 to 3 weeks. As soon as your comprehensive report is ready, our Perth clinic team will reach out to schedule your Test Review Consultation (available in-clinic in Kingsley or via Telehealth Australia-wide) to walk you through your findings and protocol step-by-step.