A ferritin of 20 may be in range by mainstream reference ranges, but for many women it is still too low to feel well, especially in perimenopause, or to keep the hairs on your head. Low iron status can overlap with thyroid symptoms and sometimes worsen hair loss, fatigue, palpitations, exercise intolerance, and brain fog.

Rising cholesterol can also travel with thyroid dysfunction, though perimenopause can contribute too. As I discuss with my patients, I would not think about this as either ferritin or thyroid. I’d think about it as: get a full workup, correct the iron issue, and make a treatment plan that looks at the whole picture. Cortisol is important and can drive T3 down too low (and reverse T3 up).Definitely worth reviewing with a clinician who will look beyond a basic TSH.