Can I get Synthroid (thyroxine) without a perscription?

NO. Synthyroid is a prescription medication used to treat thyroid conditions such as hypothyroidism (low thyroid state). It should not be used for weight loss or to "boost metabolism". There may be places to get this without a prescription but in my opinion, this would be against the pharmaceutical and medical laws of most states. If you need this medication get it from a reputable provider.