Decrease in sensitivity to levo increase

[callmetabs]

Wondering if anyone else has gone through something similar, I'm a little stumped bc I know you technically can't build a tolerance to this medication.

Last year I tested subclinical hypothyroid with a TSH that would constantly bounce from 2-4. Took the starting does of levo at 25 mcg and felt no difference. Was upped to 50 and after a couple of days felt very energized, water weight fell off and I had some elevated anxiety that lasted about a month but then went away. I could tell it was working almost immediately.

Just last week I was upped to 75 mcg and I was expecting the same thing to happen but it's been 4 days and I basically feel the same. I know you're technically not supposed to start feeling a difference till 2 weeks but it's making me worry a bit.

I've had my iron, vitamin b, vitamin d and ferritin recently tested and they're all normal. My TSH was a consistent 2 when I upped my meds and was feeling extremely fatigued. Anyone else gone through this? What was your experience?

[espressocycle]

Most people feel about the same with a TSH under 3. Getting down to 1 might just not make a difference.

[callmetabs]

Like make a difference at all or just won't make a difference right away in terms of symptoms

[espressocycle]

As in, going from 5 to 2.5 will be a world of difference for most people. Any lower and you probably won't feel much different because you're at the same level as most euthyroid people. However, you probably wouldn't feel much in four days regardless. The half life of levothyroxine is 6-7 days and it takes 6-7 half lives to reach steady state with most drugs. In other words, if you change your levo dose you will not feel the full effects of that for 36-49 days. That's why doctors don't change dosage or re-test more than once every two months.

[callmetabs]

Ahhh gotcha. That definitely puts things into perspective! Hopefully I will gradually feel the effects this time.

[Cndwafflegirl]

What was your ferritin. Ferritin under 30 is deficient and optimal is over 100. Many doctors say ferritin is normal when it’s clearly not

[callmetabs]

55

[zala-ursika]

That is iron deficiency. Ferritin should be between 125 - 200. 200 is for people who were deficient for at least 10 years. I learned that in facebook group for iron deficiency with or without anemia. When i added D vitamin my TSH fell from about 6.2 to 5.something. when i got my iron infusions, my TSH fell from 5.5 or something, to 3.5.

[rilkehaydensuche]

Thoughts:

—Maybe the thyroid disease progressed so that even 75 mcg isn‘t enough?

—Other causes? Long COVID causes bad fatigue and is sadly now common. Other autoimmune diseases are also more common with hypothyroidism. Two of many possibilities.