Changed from Levo to Erfa - First blood results

These were my results after 7 weeks on Erfa:

Free Thyroxine (FT4) 15.2 (7.0 - 17.0)

TSH 0.02 (0.20 - 4.50) (The Lab has flagged TSH as "Low".)

As the T3 was not tested, and I am feeling so well, I assume that would be high in range, too.

I was only on 50mcg of Levothyroxine, and felt I desperately needed an increase (the usual dreadful symptoms!) On my first visit to my Endo he agreed to prescribe Erfa (yes, on the NHS!!!), but research on HU leads me to wonder if 90mg of Erfa may be too high a dose?

Does the Erfa have a "cumulative" effect? I wonder if I may become over-medicated, as time goes on.

I would appreciate some advice, please.

4 Replies

  • AiryFairie,

    90mg Erfa is equivalent to 88.5mcg Levothyroxine. You really need a FT3 test to check that FT3 remains within range. You can order a private FT3 test via

    You waited seven weeks to test so FT4 and FT3 levels should have peaked and aren't likely to keep rising.

  • Thank you Clutter , I agree it is time to do a private test.

  • So nice to hear about someone doing fine on Erfa:-) And, if you started on it recently, you must be taking the "new" Erfa as the first changes were reported about two or three years ago...

    If your FT4 levels are close to the upper normal limit, you may have out-of-range FT3 levels if some of the T4 is converted to T3, along with all the T3 you are getting from the Erfa. But do you feel any hyper symptoms at all? Never mind the TSH on NDT, as it is likely to suppressed when taking T3.

  • I think I may be slightly over range - so will order a private test. I'm not sleeping well, and sometimes get too hot. Occasional palpitations. Nothing drastic, but suppose I should get it checked out. Alternatively I could drop 30mg and see how I go...

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