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.