Expert Q&A

Switching from Levothyroxine to ERFA (NDT) – Advice on sourcing in Europe/UK: what to track and how to measure progress

Understanding the Switch from Levothyroxine to ERFA NDT

As someone who has guided thousands through thyroid-related weight challenges in my book The CFP Weight Loss Method, I see the switch from levothyroxine to ERFA (natural desiccated thyroid or NDT) as a game-changer for many in their 40s and 50s. Levothyroxine provides only T4, but hormonal changes during perimenopause often impair T4-to-T3 conversion. ERFA contains both T3 and T4 in a 1:4 ratio from porcine thyroid, which can restore energy, reduce brain fog, and make fat loss possible again. Most of my clients notice improved metabolism within 4-6 weeks when dosed correctly.

Sourcing ERFA Safely in Europe and the UK

ERFA is prescription-only. In the UK, you can request it through private endocrinologists or thyroid-savvy GPs via the British Thyroid Association guidelines. Many source through online pharmacies like Pharmacy2U after obtaining a private script. In the EU, countries like Germany and Spain allow NDT through compounding pharmacies, while patients in France and Italy often order from Canadian suppliers with an EU-compliant prescription. Always verify the pharmacy holds CIPA or GPhC certification to avoid counterfeit products. Typical starting dose after switching is 30-60mg ERFA, titrated every 4 weeks based on labs and symptoms. Never self-medicate.

What Labs to Track and When

Success begins with data. Test TSH, free T4, free T3, reverse T3, and thyroid antibodies (TPO and TgAb) before switching and again 6 weeks after any dose change. Aim for TSH between 0.5-2.0 mIU/L, free T3 in the upper quartile of reference range, and a free T3/free T4 ratio above 0.3. Also monitor ferritin (target >70 ng/mL), vitamin D (>40 ng/mL), and morning cortisol. In my CFP Weight Loss approach, we layer this with fasting insulin and HbA1c because unmanaged blood sugar sabotages thyroid function and stalls weight loss in those managing diabetes.

How to Measure Real Progress Beyond the Scale

The scale often lies during the first 8 weeks due to fluid shifts. Instead, track weekly waist circumference (aim for 1-2cm loss), body fat percentage via calipers or smart scales, resting heart rate (should drop as metabolism improves), daily energy logs, and joint pain scores on a 1-10 scale. Many clients report 50% less joint pain within 6 weeks on proper NDT, making movement feasible again. Combine with my simple 3-meal intermittent fasting windows—no complex plans needed. In The CFP Weight Loss Method, we emphasize sleep tracking (7-9 hours) and stress reduction because cortisol spikes destroy T3 conversion. Expect 0.5-1kg fat loss per week once optimized, even on a middle-income budget without insurance-covered programs.

Work with a practitioner experienced in NDT. This switch, when tracked properly, often becomes the missing piece after years of failed diets.

💬 What the Community Says

The community shows strong interest in switching from levothyroxine to ERFA, especially among women aged 45-55 struggling with stubborn weight, fatigue, and joint pain. Many report life-changing energy improvements and easier weight loss once properly dosed, but sourcing remains a major frustration in the UK and Europe due to inconsistent GP support and high private prescription costs. Forums frequently discuss lab value targets, with users sharing success using private testing kits when NHS panels prove insufficient. A vocal minority warns about initial adjustment symptoms like heart palpitations, while others celebrate reduced brain fog and better blood sugar control. Most agree tracking symptoms alongside labs is essential, and many exchange tips on trusted EU pharmacies. Overall sentiment is hopeful yet cautious, with repeated calls for more doctor education on natural desiccated thyroid options.
Cite this answer
Clark, R. (2026). Switching from Levothyroxine to ERFA (NDT) – Advice on sourcing in Europe/UK: wh. *CFP Weight Loss*. https://blog.cfpweightloss.com/ask/switching-from-levothyroxine-to-erfa-ndt-advice-on-sourcing-in-europe-uk-what-to-track-and-how-to-measure-progress
Russell Clark, 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 →
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