Tsh 1.38 uiu/ml, free t4 1.35 ng/dl. are these normal levels? i lost 15lbs in 6 weeks, thinning hair, low body temp, muscle aches, dry skin.

It appears: that mIU/L and uIU/mL are interchangeable units. Most labs report normal TSH as 0.4-4.5 as normal, so your value appears to be in the low normal range. Your free T4 also seems to be normal (normal=0.8-2.7 ng/dL in most labs). Your symptoms are not consistent for either hyper OR hypothyroidism, but seem to be a combination, especially the weight loss. Continue working with your doc for diagnosis/Rx