Synthroid (Levothyroxine Sodium)

Quick info about Synthroid (Levothyroxine Sodium)

Synthroid is the less powerful of the two most popular thyroid replacement drugs on the market. It is synthetic T4, and is actually the more prescribed thyroid medication in America, but the lesser used of the thyroid drugs which are popular with bodybuilders. If you have naturally low T3 levels, then you may be able to supplement with T4, and have it convert to T3 via your body's natural metabolic pathways, which involves the deiodinase enzyme.

As compared to Cytomel, Synthroid requires significantly higher doses to be effective. Most bodybuilders don't exceed 100mcgs of Cytomel during a precontest phase of dieting, but with Synthroid the doses climb significantly higher to achieve the same results. From interviews with bodybuilders who have used Synthroid, we can summarize it is being used at up to 300mcgs/day. When you compare that to the mere 25-100mcgs/day of Cytomel that bodybuilders are typically using, we have another strike against Synthroid.