Meta Information

ID:levothyroxine

Name:Levothyroxine

Schema Version:1.5

Alternate Names

• Synthroid
• L-thyroxine
• T4

Active Compound

levothyroxine

Intervention Type

therapeutic_agent

Delivery

Route:

oral

Scope:

• systemic

Regulatory Status

• us:rx_drug
• eu:rx_drug

Indication

Focus:

disease_treatment

Description:

Treatment of hypothyroidism (underactive thyroid) to restore normal thyroid hormone levels and for pituitary TSH suppression.

Typical Protocol

• Dosage is highly individualized based on TSH blood tests, age, and weight, typically starting at 25-50 mcg daily.
• Doses are adjusted by a physician every 4-8 weeks until TSH is within the target range.
• Taken once daily on an empty stomach, 30-60 minutes before the first meal of the day.

Expected Cost Mean

Low Cost:

4

High Cost:

30

Cost Type:

monthly

Description:

Generic versions are very inexpensive; typically covered by insurance for diagnosed hypothyroidism.

Summary

Levothyroxine is a synthetic version of thyroxine (T4), a hormone produced by the thyroid gland. It is prescribed to treat hypothyroidism, a condition where the thyroid does not produce enough hormone. By replacing the deficient hormone, it restores the body's metabolic rate and resolves symptoms like fatigue, weight gain, and cold intolerance.

Purpose

Replaces thyroid hormone to correct hypothyroidism and restore metabolism.

Card Summary

A synthetic thyroid hormone used to treat hypothyroidism, restoring metabolic function.

Drug Class

thyroid_hormone_replacement

Drugs In Class

Empty Array

Impact

Score:

9.5

Justification:

Foundational for restoring normal metabolism and function in individuals with diagnosed hypothyroidism.

Evidence

Grade:

A

Score:

10

Justification:

Decades of clinical use and countless studies establish it as standard-of-care for hypothyroidism.

Safety

Score:

5.5

Justification:

Requires precise, medically supervised dosing; over-treatment causes significant cardiovascular and bone risks.

Flags

• Must be prescribed and monitored by a physician via regular blood tests.
• Over-treatment can induce hyperthyroidism, causing atrial fibrillation, anxiety, and osteoporosis.
• Has a narrow therapeutic index, meaning small dose changes can have significant effects.
• Absorption is significantly reduced by food, calcium, iron supplements, and antacids.
• Not a weight-loss or healthspan drug for individuals with normal thyroid function.

Verdict

Essential for hypothyroidism treatment; inappropriate and dangerous for general healthspan enhancement.

Created

2026-05-07T20:57:54.457194Z

Ai Model

Gemini 2.5 Pro (High)

Non Healthspan

True