Histamine Well Podcast: Exploring Histamine, Methylation & Holistic Health

One of our most downloaded episodes is back.
If you've been diagnosed with histamine intolerance, MCAS, or unexplained food sensitivities, this replay is one you won't want to miss.
In this listener-favorite episode, Joanne Kennedy explains why histamine intolerance is not a diagnosis—it's a symptom of deeper underlying health issues. While many people rely on a low histamine diet to manage symptoms, lasting improvement comes from identifying and treating the root causes driving excess histamine production.
Drawing on years of clinical experience, Joanne walks through the most common contributors to histamine intolerance, including SIBO, gut dysbiosis, leaky gut, digestive enzyme insufficiency, mold illness, oxalates, methylation issues, hormonal imbalances, and chronic inflammation.
Whether you're a practitioner, student, or someone struggling with chronic histamine symptoms, this episode will help you better understand why histamine intolerance develops—and where to start looking for answers.
Listen, Learn & Share
If this episode helps you better understand your histamine symptoms, please follow The Histamine Well Podcast, leave a review, and share it with someone searching for answers.
✨ Want more? Follow on Instagram, Facebook, and YouTube for updates and tips.

📘 New to this journey? Buy The Ultimate Bundle for Managing Histamine Intolerance—your step-by-step guide to manage your histamine intolerance effectively.
 🧪 Curious about your methylation status? Try our at-home Methylation Test! In just 15 minutes, discover if you're over-methylating or under-methylating and receive targeted supplement recommendations to help rebalance. Use code HISTAMINEWELL10 for 10% off.
🎓 Practitioner or student? Join the waitlist for the Histamine & Methylation Online Group Coaching Course starting early 2026!
📆 Work with us 1:1! Book a consultation and take your first step to real healing.

🎤 Have a topic suggestion? Submit it here!

Many people with flushing, hives, anxiety, brain fog, digestive issues, food sensitivities, and heart palpitations are told they have either histamine intolerance or Mast Cell Activation Syndrome (MCAS). While these conditions can look remarkably similar, they have very different underlying mechanisms—and understanding those differences is often the key to finding the right treatment.
In this episode, Joanne explains the difference between histamine intolerance and MCAS, why symptoms overlap, and why some people continue to react despite following a low histamine diet. Drawing on her clinical experience, Joanne explores how histamine is processed in the body, the role of DAO and HNMT enzymes, common triggers for mast cell activation, and why addressing the root cause is essential for long-term recovery.
She also discusses the connection between mould mycotoxins, gut dysfunction, SIBO, oxalates, nervous system dysregulation, and histamine-related illness, while sharing practical insights into how she approaches assessment and treatment in clinical practice.
In this episode, you'll learn:
The difference between histamine intolerance and Mast Cell Activation Syndrome (MCAS)
Why these conditions share many of the same symptoms but require different treatment approaches
How DAO and HNMT enzymes help regulate histamine in the body
Common causes of histamine intolerance, including gut dysfunction, SIBO, mould exposure, oxalates, and hormone imbalances
Why MCAS symptoms are often more severe, unpredictable, and triggered by non-food factors
The connection between mould mycotoxins, chronic inflammation, and mast cell activation
Which laboratory tests may be helpful—and why some commonly recommended tests have limited clinical value
Joanne's clinical approach to identifying and treating the root causes of histamine-related symptoms
Whether you're navigating histamine intolerance, suspect MCAS, or you're a healthcare practitioner wanting a deeper understanding of these complex conditions, this episode provides practical, evidence-informed insights to help you take the next step towards better health.
✨ Want more? Follow on Instagram, Facebook, and YouTube for updates and tips.

📘 New to this journey? Buy The Ultimate Bundle for Managing Histamine Intolerance—your step-by-step guide to manage your histamine intolerance effectively.
 🧪 Curious about your methylation status? Try our at-home Methylation Test! In just 15 minutes, discover if you're over-methylating or under-methylating and receive targeted supplement recommendations to help rebalance. Use code HISTAMINEWELL10 for 10% off.
🎓 Practitioner or student? Join the waitlist for the Histamine & Methylation Online Group Coaching Course starting early 2026!
📆 Work with us 1:1! Book a consultation and take your first step to real healing.

🎤 Have a topic suggestion? Submit it here!

Many women enter their 40s expecting a few hormonal changes, but are often unprepared for the anxiety, sleep disturbances, fatigue, low mood, histamine symptoms, weight changes, and nervous system shifts that can accompany perimenopause.
In this episode, Joanne shares her clinical and personal experience working with women through perimenopause and menopause, including her own journey with bioidentical oestrogen and progesterone. She discusses the signs of low oestrogen and progesterone, the limitations of standard hormone testing, and how bioidentical hormone therapy may support women during this transition.
You'll learn:
The difference between perimenopause and menopause
Common symptoms of low oestrogen and low progesterone
How hormonal changes can influence histamine intolerance and mast cell activation
Why hormone blood tests don't always tell the full story
The potential benefits and challenges of bioidentical oestrogen and progesterone
The connection between hormones, anxiety, sleep, mood, energy, libido, and weight
Why hormone therapy should be individualised rather than one-size-fits-all
Whether you're navigating perimenopause yourself or supporting women through this stage of life, this episode offers practical insights to help you better understand the relationship between hormones, histamine, and healthy ageing.
✨ Want more? Follow on Instagram, Facebook, and YouTube for updates and tips.

📘 New to this journey? Buy The Ultimate Bundle for Managing Histamine Intolerance—your step-by-step guide to manage your histamine intolerance effectively.
 🧪 Curious about your methylation status? Try our at-home Methylation Test! In just 15 minutes, discover if you're over-methylating or under-methylating and receive targeted supplement recommendations to help rebalance. Use code HISTAMINEWELL10 for 10% off.
🎓 Practitioner or student? Join the waitlist for the Histamine & Methylation Online Group Coaching Course starting early 2026!
📆 Work with us 1:1! Book a consultation and take your first step to real healing.

🎤 Have a topic suggestion? Submit it here!

Methylation has become one of the hottest topics in functional medicine, biohacking, and wellness. From MTHFR testing to methylated supplements, many people are being told that boosting methylation is the key to better energy, mood, detoxification, hormone balance, and longevity.
But what if more methylation isn't always better?
In this episode, Joanne explores the science behind methylation, the roles of MTHFR and COMT, and why relying solely on genetic reports can lead to inappropriate supplementation. Joanne explains the difference between undermethylation and overmethylation, the symptoms of excess methyl groups, and why many people experience worsening anxiety, insomnia, irritability, and other adverse effects when taking methylated supplements.
Whether you're a practitioner, student, or someone navigating histamine intolerance, hormone imbalances, or chronic health concerns, this episode provides a balanced, evidence-informed perspective on one of today's most talked-about health trends.
In this episode, you'll learn:
What methylation is and why it's essential for health
How methylation affects neurotransmitters, hormones, detoxification, and gene expression
The difference between undermethylation and overmethylation
The role of MTHFR, COMT, folate, and vitamin B12 in methylation pathways
Common symptoms of excess methyl groups
Why genetic testing alone doesn't tell the whole story
The potential risks of methylated supplements
A more personalised approach to methylation support
✨ Want more? Follow on Instagram, Facebook, and YouTube for updates and tips.

📘 New to this journey? Buy The Ultimate Bundle for Managing Histamine Intolerance—your step-by-step guide to manage your histamine intolerance effectively.
 🧪 Curious about your methylation status? Try our at-home Methylation Test! In just 15 minutes, discover if you're over-methylating or under-methylating and receive targeted supplement recommendations to help rebalance. Use code HISTAMINEWELL10 for 10% off.
🎓 Practitioner or student? Join the waitlist for the Histamine & Methylation Online Group Coaching Course starting early 2026!
📆 Work with us 1:1! Book a consultation and take your first step to real healing.

🎤 Have a topic suggestion? Submit it here!

Could histamine be contributing to Premenstrual Dysphoric Disorder (PMDD)?
In this episode of The Histamine Well Podcast, Joanne explores the growing interest in the connection between PMDD, histamine intolerance, mast cell activation, and hormonal fluctuations. As more women report improvements in PMDD symptoms with antihistamines, the question is gaining attention: could histamine be a missing piece of the PMDD puzzle?
Joanne breaks down the science behind the estrogen-histamine feedback loop, explains how histamine interacts with estrogen and progesterone throughout the menstrual cycle, and discusses why some women experience worsening mood symptoms during the luteal phase.
You'll learn about the role of mast cells, neurotransmitters, neuroinflammation, and hormone sensitivity in PMDD, as well as the potential benefits and limitations of H1 and H2 antihistamines. Joanne also shares her clinical observations on histamine-related hormone symptoms and why addressing underlying drivers of histamine excess may be essential for long-term symptom improvement.

In This Episode You'll Learn:
What PMDD is and how it differs from PMS
The relationship between histamine and women's hormones
How estrogen can increase histamine levels
The role of progesterone in histamine regulation
Mast cell activation and hormone-related symptoms
Why histamine may worsen anxiety, irritability, and mood swings
The science behind H1 and H2 blockers
Potential risks of long-term antihistamine use
Histamine's effects on neurotransmitters including serotonin and dopamine
The connection between PMDD, MCAS, and histamine intolerance
Why methylation may play a role in PMDD symptoms
Common root causes of histamine excess, including SIBO, mold exposure, oxalates, and gut dysfunction
Natural strategies for addressing histamine-related hormone symptoms
✨ Want more? Follow on Instagram, Facebook, and YouTube for updates and tips.

📘 New to this journey? Buy The Ultimate Bundle for Managing Histamine Intolerance—your step-by-step guide to manage your histamine intolerance effectively.
 🧪 Curious about your methylation status? Try our at-home Methylation Test! In just 15 minutes, discover if you're over-methylating or under-methylating and receive targeted supplement recommendations to help rebalance. Use code HISTAMINEWELL10 for 10% off.
🎓 Practitioner or student? Join the waitlist for the Histamine & Methylation Online Group Coaching Course starting early 2026!
📆 Work with us 1:1! Book a consultation and take your first step to real healing.

🎤 Have a topic suggestion? Submit it here!