What does thyroxine mean?
Thyroxine is an iodine-containing hormone produced by the thyroid gland and commonly known as T4. It helps regulate metabolism, influencing how the body uses energy, and also contributes to normal growth and development. A deficiency can cause hypothyroidism, which may be treated with thyroid-hormone replacement. In British medical usage, “thyroxine” can refer both to the natural hormone and to medicinal preparations; in American usage, the synthetic form is generally called levothyroxine. The word is primarily used in medicine, endocrinology, and biological science rather than in everyday conversation. Its chemical importance is also reflected in its name and common abbreviation: T4 identifies the four iodine atoms present in each hormone molecule. Understanding thyroxine is useful because thyroid function affects energy, cardiovascular activity, temperature regulation, and numerous other physiological processes.
nounThyroxine is a hormone containing iodine that is produced by the thyroid gland and helps regulate the body's metabolism, growth, and development. The term may also refer to a pharmaceutical preparation of the hormone used to treat certain thyroid disorders.
- The iodine-containing hormone secreted by the thyroid gland that regulates metabolism and supports normal growth and development.
- A medicinal preparation of thyroid hormone used in the treatment of certain thyroid deficiencies.
"Blood tests showed that her thyroxine levels were unusually low."
"The doctor prescribed thyroxine after the blood tests confirmed severe hypothyroidism."
"Research is focused on how thyroxine influences energy use in different tissues."
The plural is grammatically possible but rarely used because the word usually refers to a specific hormone or a medicinal substance.
"The study compared the effects of different thyroxines in laboratory animals."
Thyroxine is often called T4 because each molecule contains four iodine atoms—an essential part of the hormone's remarkable chemical design.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Words that share this root
How thyroxine is actually used
This is a formal medical and scientific term. In clinical contexts it is frequently abbreviated T4; in American usage, the synthetic medication is more commonly called levothyroxine.
Easily confused with thyroxine
Thyroxine is the natural thyroid hormone, while levothyroxine is a synthetic medicinal form of it used in thyroid-hormone replacement treatment.
The thyroid is the gland that produces thyroxine; thyroxine is one of the hormones it secretes.