McCall McPherson explains why some people don't feel better on T4 medication alone. Poor converters struggle to turn T4 into active T3, causing fatigue, brain fog, weight gain, dry skin, and hair loss despite normal blood tests.
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And sadly, the premise and promise of medicine with these T4 or levothyroxine based drugs is operating completely and entirely under the assumption that we can efficiently and effectively convert that crude oil to gasoline to make this hormone usable in our physiology. The reality is many people cannot for a slew of reasons but conversion problems difficulty converting T4 to T3 is a pervasive issue and in fact 100% of people at modern thyroid clinic are poor converters. Symptoms of poor conversion are simply you're being treated for your thyroid condition and guess what? You still have a whole slew of thyroid hormones. So fatigue, brain fog, weight gain, dry skin, brittle nails, brittle hair, low sex drive, high cholesterol, cold intolerance, loss of the outer portion of your eyebrows, pre diabetes, elevations in blood sugar, diabetes, all of those things. And listen closely because it doesn't matter how many times your clinician increases and decreases your dose of levothyroxine, if you are a poor converter, you will never have enough gasoline in your tank to effectively and efficiently work in terms of your physiology.