Both Levothyroxine and Synthroid contain the same active ingredient, levothyroxine sodium. Your doctor determines the appropriate dosage based on individual factors like age, weight, and thyroid function test results. This dosage is usually adjusted gradually until optimal thyroid hormone levels are achieved, monitored through blood tests.
Administration
Both medications are typically taken orally, once daily, on an empty stomach, at least 30-60 minutes before breakfast. This timing maximizes absorption. Avoid taking them with calcium supplements, iron, or antacids, as these can interfere with absorption. If you’re taking other medications, inform your physician to assess potential interactions.
Differences in Formulation
While the active ingredient is the same, Synthroid and Levothyroxine may differ slightly in their inactive ingredients (excipients). These differences are generally not clinically significant for most patients, but some individuals may report improved tolerance or efficacy with one brand over the other. This should be discussed with your doctor. Changes should always be made under physician supervision.
Dosage Adjustments
Dosage adjustments are common, particularly during initial treatment or when circumstances change (like pregnancy). Your doctor will monitor your thyroid hormone levels (TSH, T3, and T4) via blood tests to guide dosage adjustments. Don’t alter your dosage without consulting your doctor. Report any side effects immediately.
