Expert Q&A

Switching from Levothyroxine to ERFA (NDT) – Advice on sourcing in Europe/UK — how a functional medicine approach differs specifically for women over 40?

Why Consider Switching from Levothyroxine to ERFA Natural Desiccated Thyroid

For women over 40 dealing with stubborn weight, fatigue, and hormonal shifts, many find that Levothyroxine alone fails to resolve symptoms. Synthetic T4-only medication often leaves T3 levels suboptimal, especially amid perimenopause when estrogen decline disrupts thyroid conversion. In my 30-Week Tirzepatide Reset protocol, we prioritize full-spectrum thyroid support because unresolved hypothyroidism sabotages metabolic reset. ERFA, a natural desiccated thyroid (NDT) containing T4, T3, T2, and T1 from porcine sources, frequently delivers better energy, mood stability, and fat loss for this group.

How a Functional Medicine Approach Differs for Women Over 40

Unlike conventional care that titrates based solely on TSH, our functional method examines root causes: lectin-induced inflammation, toxin burden, insulin resistance, and adrenal stress. For women over 40, we test free T3, reverse T3, antibodies, ferritin, and cortisol patterns. The protocol integrates low-dose tirzepatide cycling with a lectin-free, low-carb diet from the 221 recipes in The 30-Week Tirzepatide Reset. We add targeted Detox Drops, red light therapy via our Unlimited Red Bed Club, and Japanese-style walking intervals to reduce inflammation and support hormone balance. This addresses why previous diets failed and makes joint pain manageable through gradual movement rather than intense exercise.

Practical Steps for Switching Safely

Never switch abruptly. We typically reduce Levothyroxine by 25-50 mcg while introducing ERFA at 30-60 mg, monitoring every 4-6 weeks with full thyroid panels. Patients follow the book's 69 Transformation Steps: eliminate grains and ultra-processed carbs, practice chaotic intermittent fasting in maintenance, and track body composition. Most see 8-15 lbs lost in the first 70-day cycle when thyroid is optimized alongside tirzepatide. Focus on non-scale victories like better sleep, reduced blood pressure, and stable blood sugar—critical for those managing diabetes.

Sourcing ERFA in Europe and the UK

ERFA is prescription-only. In the UK, work with private functional practitioners or endocrinologists open to NDT; some NHS GPs approve under shared-care. Across Europe, countries like Germany and Spain allow easier access via compounding pharmacies or online EU-licensed pharmacies with a valid prescription. Avoid unregulated sources to prevent inconsistent dosing. Telehealth options through clinics like CFP Fit Now can guide prescriptions and monitoring. Pair this with our protocol's emphasis on real-food detox to achieve the metabolic freedom described in The 30-Week Tirzepatide Reset—true healing beyond medication dependency.

💬 What the Community Says

Women over 40 in UK and European forums report mixed experiences switching from Levothyroxine to ERFA NDT. Many praise improved energy and easier weight management after years of feeling suboptimal on T4-only meds, especially when addressing perimenopause symptoms. A common theme is frustration with NHS resistance to NDT prescriptions, pushing people toward private functional doctors or overseas sourcing. Success stories often mention combining NDT with anti-inflammatory diets, though some debate exact conversion ratios from synthetic doses. Concerns about sourcing reliability and consistent potency appear frequently, with users sharing tips on approved EU pharmacies. The community splits on whether NDT is truly superior or if optimized Levothyroxine plus lifestyle changes suffices. Those managing blood pressure or blood sugar alongside weight loss tend to value integrated approaches that include movement and detox support. Overall, lived experiences highlight the need for personalized testing and gradual transitions rather than one-size-fits-all advice.
Cite this answer
Clark, R. (2026). Switching from Levothyroxine to ERFA (NDT) – Advice on sourcing in Europe/UK — h. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/switching-from-levothyroxine-to-erfa-ndt-advice-on-sourcing-in-europe-uk-how-a-functional-medicine-approach-differs-specifically-for-women-over-40
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

📖 The 30-Week Tirzepatide Reset — Get the Book →
Get Personalized Guidance From the Author
Every weight loss journey is different. Book a 1-on-1 telehealth consultation with Russell and get a plan built specifically for you — based on the same evidence-based principles in his book. Available to patients in all 50 states.
Book Your Consultation →
Have a follow-up question?
More Questions 200 answered
▸ Fixing a skinny fat physique with just diet and its effect on metabolism and insulin levels: what to track and how to measure progress? ▸ Why does I lost 45 pounds in 6 months without any exercise during the weight loss plateau phase? ▸ How to be okay with loose skin when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ Fixing a skinny fat physique with just diet and its effect on metabolism and insulin levels during the weight loss plateau phase? 📖 Tirzepatide — A dual-acting medication targeting both GLP-1 and GIP receptors, providing a more comprehensive metabolic signal than si… ▸ Eyelid myokymia/twitching caused by oral progesterone — what does the research actually say and its effect on metabolism and insulin levels? ▸ How do I stop the lunch trap from ruining my deficit when im out of the house all day on a low-carb or ketogenic diet: best practices and common mistakes to avoid? ▸ Blue Honey v Tincture — how a functional medicine approach differs for long-term maintenance (not just short-term)? 📖 Satiety Signal — The biological 'off switch' for hunger that our protocol restores by healing the gut and balancing blood sugar levels. ▸ Switching from Levothyroxine to ERFA (NDT) – Advice on sourcing in Europe/UK — how a functional medicine approach differs for people with insulin resistance? ▸ How does reversing it doesn’t reslly solve it, does it for long-term results — what the research actually says? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Chosen foods avocado oil, should I be sauteeing my veggies in it for people with insulin resistance for people with insulin resistance? ▸ Is compounded semaglutide with B12 worth choosing over B6 or plain and its effect on metabolism and insulin levels specifically for women over 40? ▸ Nausea after CJC-1295 injection - ok or bad batch and the role of cortisol and stress hormones while doing intermittent fasting? ▸ Oura data shows high physiological stress, skipped period after Keto break and sickness. Should I push through with fasting or listen to the ring — how a functional medicine approach differs on a low-carb or ketogenic diet? 📖 Anti-Inflammatory Protocol — A way of eating that prioritizes whole foods and eliminates triggers to quiet the internal 'fire' that prevents fat cell… ▸ How the prices looking in your neck of the woods and its effect on metabolism and insulin levels on a low-carb or ketogenic diet? ▸ What keto plus compounded tirzepatide for the last five months looked like when you have PCOS or hormonal imbalances for long-term maintenance (not just short-term)? ▸ Before being diagnosed, did we all assume everyone was this tired all the time — how a functional medicine approach differs on a low-carb or ketogenic diet? 📖 Insulin Resistance — A condition where your cells stop responding to insulin, locking fat in storage; our protocol is designed to unlock thes… ▸ How do i not compare myself to others when you have PCOS or hormonal imbalances and how it connects to gut health and inflammation? ▸ Stacking NMN with TMG, what's your morning fasted protocol look like during the weight loss plateau phase when you have PCOS or hormonal imbalances? ▸ Am I allowed to ask about trusted suppliers for people with insulin resistance — what the research actually says? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Doesn't Barbra Streisand belong to us too: best practices and common mistakes to avoid for those with hypothyroidism or Hashimoto’s? ▸ Anyone else's family think they're crazy for eating this way on a low-carb or ketogenic diet and its effect on metabolism and insulin levels? ▸ - [Workout Wednesday] – What’s your fitness look like when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ Research on Peptides for Nerve Regeneration and Ligament Repair if you're on a GLP-1 like semaglutide or tirzepatide: best practices and common mistakes to avoid? 📖 Tirzepatide Micro-Dosing — The practice of using the lowest effective dose to achieve results, minimizing side effects while maximizing the longevi… ▸ Why does Guyz need some advice , should I go on a cut to improve insulin resistance? Reducing body fat is the key if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Shot doesn’t feel like it’s going into skin - bad batch — what do certified weight loss coaches recommend for those with hypothyroidism or Hashimoto’s? ▸ Will this help — evidence-based answer for CFP patients for long-term maintenance (not just short-term)? ▸ Should i really be aiming for 45 zone 2 minutes per day for fat loss when you have PCOS or hormonal imbalances specifically for women over 40? ▸ 1 year postpartum + thyroid swings—heart tests normal but I still feel my heartbeat every day. Anyone else when you have PCOS or hormonal imbalances: what to track and how to measure progress? 📖 Lectin-Free Living — Eliminating inflammatory plant proteins that damage the gut lining and trigger the autoimmune responses that often stall… 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Finally diagnosed with PCOS. Now what if you're on a GLP-1 like semaglutide or tirzepatide — what the research actually says? ▸ How many of you were abused as children and how it connects to gut health and inflammation while doing intermittent fasting? ▸ A1c was 7.1, tips for regulating MODY 2 with lifestyle changes when you have PCOS or hormonal imbalances — what certified coaches recommend? 📖 Hormonal Chaos — The internal state of imbalance caused by modern grains and refined carbs that overrides willpower and forces the body t… ▸ Which needle length and gauge: how to talk to your doctor about this when you have PCOS or hormonal imbalances? ▸ How the prices looking in your neck of the woods and how it connects to gut health and inflammation — what the research actually says? ▸ Finally diagnosed with PCOS. Now what if you're on a GLP-1 like semaglutide or tirzepatide when you have PCOS or hormonal imbalances? ▸ Has anyone here fixed their soul-crushing depression by changing diet during the weight loss plateau phase — what certified coaches recommend? ▸ Does anyone else’s health anxiety get MUCH worse at night — what most people get wrong about this: best practices and common mistakes to avoid? ▸ POLL At what strength did Semaglutide become effective for you for those with hypothyroidism or Hashimoto's during the weight loss plateau phase? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Actually wanting to wake early for those with hypothyroidism or Hashimoto's for those with hypothyroidism or Hashimoto’s? 📖 Phase 1: Priming — The first 48 hours of a 70-day cycle focused on high-fat intake to prevent the brain from triggering a starvation respon… ▸ How does messes with autophagy after a weight loss plateau when you have PCOS or hormonal imbalances? ▸ Chosen foods avocado oil, should I be sauteeing my veggies in it for people with insulin resistance during the weight loss plateau phase? ▸ Microdosing and eating habits — what do certified weight loss coaches recommend if you're on a GLP-1 like semaglutide or tirzepatide? 📖 Leptin Sensitivity — Restoring your brain's ability to hear the 'I am full' signal, which is often muted by high-sugar diets and systemic inf… ▸ Can I use Bears Head (Hericium americanum) in place of Lions Mane and how it connects to gut health and inflammation if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Fruit Salsa - First Week/Phase One Approved: what to track and how to measure progress on a low-carb or ketogenic diet? ▸ How would you Stack peptides on a low-carb or ketogenic diet for people with insulin resistance? 📖 High-Dose Dependency — The pharmaceutical trap of staying on maximum medication doses indefinitely, which we avoid through our smart cycling me… ▸ App that can predict symptoms before they get bad: what to track and how to measure progress on a low-carb or ketogenic diet? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Thyroiditis pain - how long and treatment — what do certified weight loss coaches recommend for those with hypothyroidism or Hashimoto’s? ▸ Dizzy feeling plus high blood pressure and its effect on metabolism and insulin levels: best practices and common mistakes to avoid? ▸ I’m looking into possibly going grain free and I was wondering if it was just as healthy as doing keto or paleo when you have PCOS or hormonal imbalances when you have PCOS or hormonal imbalances? 📖 Metabolic Flexibility — The body’s ability to efficiently switch between burning carbohydrates and burning stored body fat based on availability… ▸ Has anybody seen one of these billboards near the airport for people with insulin resistance: best practices and common mistakes to avoid? ▸ Why does giving advice to others about mental health feel so much easier than following the same advice for yourself when you have PCOS or hormonal imbalances while doing intermittent fasting?