I had a TT a few years ago. Before that, I was thyroid meds for hypothyroidism for 14 years and didn't have any hairloss. After my TT I started on Synthroid (before that I took Levoxyl) and the hairloss started almost immediately. It would be pretty significant for awhile and then taper off. Then I'd have a dosage change and it would start again. I noticed a pattern over time......everytime my meds changed, the hair started coming out. My doc recommended Evening Primrose Oil which I figured was a bunch of hog wash but I started it anyway. He said it would take at least 6 months to a year to really notice any changes. He said it won't stop the hairloss but it will make my hair and the follicles much healthier. I have to say, it's been 3 years now and I have got a head of hair that is very healthy. It still comes out every now and again but nothing like it did. The loss will level out over time and then stop altogether. Mine comes and goes. Luckily, I was blessed with a ton of hair to start with and the only thing I really noticed was that it got a lot thinner and dryer. But, it's thick and healthy now. Like I said, I only noticed it at dosage changes. It's like your body just kind of panics for a bit and then once things get regulated it tapers off. That is just my experience with it.