Which is better? I have been on levothyroxine many years. After being on the increased dosage .75mcg for 5 weeks I noticed increased energy (which was a big problem) but also a negative of hair loss. Now I've been on Synthroid .50mcg 3 weeks & upped dosage of .75mcg for 1 week. I know it's too soon to compare but I do have the hair loss still & still tired & I'm really irritable. Poor husband! I'm wondering if I should have stayed on the Levothryoxine a bit longer. The Synthroid is a lot more expensive too.