SugarBabie replied: "Yes, synthroid can definately cause this. It can also cause anxiety and panic attacks. You need to take it early in the morning, about an hour before you eat breakfast. Take it on an empty stomach, with a glass of water, and nothing else. Keep it by your bedside table so you don't forget to take it as soon as you wake up. Then have your shower, etc and have breakfast last, so there is as much time as possible between taking it and eating. Vitamins, minerals, some foods and even other meds can interfere with it. You need to get it into your system before anything else and as early as possible in the day. Do not take any vitamins or supplements with it, as they can make it less effective. Taking it in the morning helps avoid the insomnia from it. If you find that it still causes insomnia after a couple of weeks after taking it in the morning, you should talk to your doctor about reducing your dose. If your thyroid is underactive, you NEED this medication, so work with your doctor or pharmacist to find the right dose for you. Some people just don't tolerate this medication well. I'm one of them. This was the advice my pharmacist gave me. She's on the same medication and had the same problems. Good luck! Side Effects of Synthroid - for the consumer Synthroid All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Synthroid: Anxiety; diarrhea; flushing; mood swings; muscle weakness; partial, temporary hair loss; sleeplessness; stomach cramps; tiredness; vomiting. Seek medical attention right away if any of these SEVERE side effects occur when using Synthroid: Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); changes in appetite; changes in menstrual periods; chest pain; difficulty breathing; excessive sweating; fast heartbeat; fever; headache; hives or skin rash; hyperactivity; inability to handle warm or hot room/weather conditions; irregular heartbeat; irritability; leg cramps; nervousness; pounding in the chest; seizures; shortness of breath; tremors; weight gain or weight loss."

DRL replied: "Yes, my wife has an underactive thyroid and is on 125 mcg of Synthroid, 100mg (I think) of Metformin. She took Clomid about 5 years ago for a while but has since been taken off that. It's not a big deal. Just be sure to take Synthroid in the morning before you eat, you need to wait 30 minute-1 hour (preferably closer to an hour). And make sure you take Metformin at night with dinner otherwise it will upset your stomach and give you the runs."