-2%
- Continue taking even if you feel better—this is usually a lifelong therapy.
- Inform your doctor if you become pregnant, change medications, or experience symptoms of hyperthyroidism.
- If you miss a dose, take it as soon as you remember. If it’s nearly time for the next dose, skip the missed dose—do not double up.
- Do not use Thyrox 12.5 as a weight loss aid in euthyroid individuals.
- Monitor Regular thyroid function tests (TSH, T4)
- Monitor heart rate, blood pressure, and clinical signs of over- or under-replacement
- Adjust dose based on weight changes and lab results
Thyrox 12.5 is a synthetic thyroid hormone replacement used in the treatment of hypothyroidism, a condition where the thyroid gland fails to produce adequate thyroid hormone. Restoring normal hormone levels helps regulate energy, metabolism, and overall body function.
Thyrox 12.5 contains levothyroxine sodium, a synthetic form of the natural thyroid hormone T4. It increases basal metabolic rate (BMR), promotes protein synthesis, and stimulates metabolism of carbohydrates, fats, and vitamins. Its activity is largely mediated through conversion to triiodothyronine (T3) at the cellular level, influencing growth, development, and metabolic regulation.
Your healthcare provider will determine the appropriate starting dose based on your thyroid hormone levels, assessed via blood tests. Once therapy begins, periodic monitoring is essential to ensure optimal dose adjustment and therapeutic effectiveness.
Adult Dosing
Mild Hypothyroidism: 1.7 mcg/kg/day; usual initial dose: 25–50 mcg/day.
Age >50 or with cardiovascular disease: Start at 12.5–25 mcg/day; titrate every 4–8 weeks.
Severe Hypothyroidism: Begin with 12.5–25 mcg/day; increase by 25 mcg/day every 2–4 weeks as needed.
Pediatric Dosing
Neonates & Infants (1–12 months): 6–15 mcg/kg/day.
Children (1–12 years): 4–6 mcg/kg/day.
Adolescents (>12 years): 2–3 mcg/kg/day or up to 150 mcg/day.
- Dosing should be individualized based on body weight, age, and disease severity.
- Untreated thyrotoxicosis (hyperthyroidism)
- Uncorrected adrenal insufficiency
- Recent myocardial infarction (MI)