Has anyone here read or head anything about labetalol having an effect on low thyroid? My GP wants me to wean off labetalol and try something else. I'm currently taking 200 mg twice a day. I'm also trying to get my low thyroid under control. I take .75mg of the generic synthroid for that. I know that labatalol is not particularly good for people with overactive thyroid, or hyperthyroid, but I've never seen anything about hypothyroid and labetalol. A cardiologist I saw recently also expressed some concern about labetalol use. The GP wrote a prescription for 100 mg, then wants me to get off it eventually. But he never said exactly why.