Question: what is the difference between synthroid and levothyroxine sodium?
Answer: Are Synthroid and Levothroid the Same Thing? Synthroid (levothyroxine sodium) and Levothroid (levothyroxine sodium) are replacements for hormones produced by the human thyroid gland used to treat hypothyroidism (low thyroid hormone). Synthroid is also used for pituitary TSH suppression.