Welcome to HCM. I am happy to assist you today with the resolution of your medical concerns. Actually this history is incomplete. I am interested in asking some questions before I can come to a single point diagnosis:- Do you feel palpitations (racing heart)? Do you feel excessive sweating? Heat Intolerance? weight loss of unexplainable reason? Decreased concentration? How much dosage and how many times a day of Liothyronin (Cytomel ) are you taking? Have your doctor recently raised the dosage or frequency of medication? Do you have issue with falling asleep? OR you fall asleep fine but have problem staying asleep??? Do you feel depressed? Low mood? Worthlessness in life?? Lack of interest in daily life activities? Actually, taking cytomel near bedtime can do nothing based on the limited history and case details. It may instead aggravate the issue if this is due to high dose of medicine. But Your doctor has more Case details regarding you, so he can judge better, based on the advantage of doing physical examination. You need to go for a lab test for Thyroid profile to see if you are taking appropriate dose of Cytomel. When you get the reports, feel free to go to my profile, and below my profile picture click on Ask Me A Question and I will be there with you to solve your issue. I will also review your case details as I asked above. Thanks for having a trust in HCM. Take care. Regards! DR.HANIF USA