*This statement summarizes the third USPSTF recommendations for screening for chlamydial infection and the supporting scientific evidence, and it updates the 1995 recommendations contained in the Guide to Clinical Preventive Services, second edition (1).
What are the possible side effects of levothyroxine (Levothroid, Levoxyl, Synthroid, Tirosint, Unithroid)? Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as: headache;
Read More. Seems like the big hazards are supplements and meds taken too soon before or after the Synthroid, but the Physician's Desk Reference also includes this: A high-fiber diet, soy-containing supplements, and walnuts can also interfere with the effects of levothyroxine..