I know this is an old post, but something worth mentioning. If you have low thyroid then you can have low T. If your metabolic rate is slower, then hormone production is slower. Even when labs show you are in range for TSH, T4 and T3 that doesn't mean there is not a thyroid problem. Just like T, if you fall from levels that were once perfect for you - you will suffer, even though you are in range. I was getting low normal range T results and questionable within range thyroid results. I wasn't sleeping. I was a bit depressed, I was anxious. I had cold hands and feet. I lost fat weight. I looked cut to the bone. I could lift and I wanted to, but I lacked drive and gains. It was all pointing to T. It didn't look like a normal thyroid issue. But especially for the more athletic individual, hypo can also make you lose weight - an efficient mechanism of adrenalin and cortisol jump in to sustain metabolic rate and blood sugar respectively. That adrenalin kept me awake and I had so much cortisol I could not feel the pain of old injuries and knocks.
I experimented with TRT and HCG. Both sent my heart pounding and increased insomnia and weight loss issues in short time. My gut instinct, and previous cycles told me I was lacking something else more immediately important than T - thyroid. I began taking iodine in the form of Lugols solution 12%. After an initial detox few days I began to feel changes. My hands and feet felt warm for the first time in a year. I slept longer and deeper. I had a boner that lasted through the last three hours of my sleep every night! My research was thorough and anyone who thinks iodine is a dangerous, toxic substance needs to see the work of US doctors Abrahams and Bernstein. At my peak I hit 200mg a day then pulledback to 80 - my current dose after 2 months. The feeling of confidence and elation was superb on occasion (like being in my 20's again), though there were hurdles of rebalancing hormones to get through over the weeks. My T levels are up, my sex drive is up and I am putting weight on. My blood sugar issues are resolving. In an iodine deficiency the thyroid can go both hyper and hypo according to the individual. But be sure that many , many people are deficient, especially athletes. I just feel better and will continue with the iodine. 15mg in a large glass of water with every meal and before bed works for me. I take magnesium glycinate all day, selenium and c in the morning - all important thyroid co factors, and plenty of good quality rock salt balanced by potassium in bananas.
This might not be the answer to everyone's TRT insomnia but thyroid issues sneak up slowly and can lower your T. I've done cycles of 750 Sus a week and slept like a baby for nine hours - this is how I knew another hormonal culprit was at large for my 'natural' insomnia. Total repletion could take 6 months to a year, but it probably took over ten years to lose my iodine, so I'm happy to be patient for a few months. Best of all, I can handle all kinds of stress again. I hope this experience is useful to some - not every 'apparent' TRT scenario is that simple.