Peter Attia· MD
what you see sometimes is that you give a patient T4 and they start to feel worse and sometimes their TSH actually improves and the reason it improves is T4 does have some inhibition of TSH not as much as T3 but some but what if for physiologic reasons their D1 and D2 are being down regulated while their D3 is being upregulated and they're taking that T4 that you're giving them and they're just making more and more reverse T3