Short answer: The Tirosint label gives one capsule dose a day on an empty stomach, one-half to one hour before breakfast, swallowed whole. The average full adult replacement dose is about 1.6 mcg/kg/day (100 to 125 mcg for a 70 kg adult). The dose is adjusted by 12.5 to 25 mcg every 4 to 6 weeks; older people and those with heart disease start at 12.5 to 25 mcg a day.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Tirosint is approved for: Tirosint is approved for adults and children 6 years and older as replacement therapy for hypothyroidism from any cause (thyroid, pituitary or hypothalamic, present at birth or acquired), and as an add-on to surgery and radioiodine to suppress TSH in TSH-dependent well-differentiated thyroid cancer. It is not approved to suppress benign thyroid nodules or nontoxic goiter in people with enough iodine, or for short-term hypothyroidism during recovery from subacute thyroiditis (section 1).
Source
TIROSINT (levothyroxine sodium) capsules, for oral use, prescribing information and Patient Information. IBSA Pharma. DailyMed, version published March 27, 2026. DailyMed setid 7a7ade79-0165-4e31-b84e-667416c00c7e
Tirosint is taken by mouth once daily on an empty stomach, one-half to one hour before breakfast, and at least 4 hours before or after drugs that interfere with its absorption (section 2.1).
Capsules are swallowed whole and not cut, crushed or chewed. Children under 6, or anyone unable to swallow an intact capsule, do not use it (sections 2.1 and 2.3).
It comes in 15 strengths from 13 mcg to 200 mcg. Capsules stay in the blister until use (sections 3 and 16).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Group | Starting dose | How the dose is changed |
|---|---|---|
| Healthy, non-elderly adults hypothyroid a short time | Full replacement, about 1.6 mcg/kg/day (100-125 mcg/day for a 70 kg adult) | 12.5 to 25 mcg every 4 to 6 weeks until TSH is normal |
| Older people or heart disease | 12.5 to 25 mcg/day | Every 6 to 8 weeks as needed |
| Severe longstanding hypothyroidism | 12.5 to 25 mcg/day | 12.5 to 25 mcg every 2 to 4 weeks |
| Age | Daily Dose Per Kg Body Weight |
|---|---|
| 6-12 years | 4-5 mcg/kg/day |
| Greater than 12 years but growth and puberty incomplete | 2-3 mcg/kg/day |
| Growth and puberty complete | 1.6 mcg/kg/day |
Doses above 200 mcg per day are seldom required. A poor response to more than 300 mcg per day is rare and may point to missed doses, poor absorption, drug interactions or a mix of these. In older people the full dose may be under 1 mcg/kg/day.
Children at risk of hyperactivity start at one-fourth of the full replacement dose and add one-fourth each week until the full dose is reached.
Pregnancy: with pre-existing hypothyroidism and TSH above the trimester range, the dose is raised by 12.5 to 25 mcg per day with TSH checked every four weeks, then returned to the pre-pregnancy dose right after delivery. New-onset hypothyroidism starts at 1.6 mcg/kg/day, or 1.0 mcg/kg/day if TSH is under 10 mIU per liter.
For thyroid cancer, TSH is generally suppressed below 0.1 mIU per liter, which usually needs more than 2 mcg/kg/day.
Adults: TSH is checked 6 to 8 weeks after any dose change, then every 6 to 12 months on a stable dose. For pituitary or hypothalamic hypothyroidism, free-T4 is used instead and kept in the upper half of normal.
Soybean flour, cottonseed meal, walnuts and dietary fiber may lower absorption, and grapefruit juice may delay it; regular intake within an hour of such foods may call for a dose review (section 2.1).
The Tirosint label gives no missed-dose instruction. Neither the prescribing information nor the Patient Information says what to do if a dose is missed.
More on this: missed a dose of Tirosint.
In Dose Track you set up Tirosint as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.