Cytomel T3 (Lyothironine)


25 mg per tablet, 100 tablets per vial.

Cytomel T3 is a thyroid hormone that affects the body’s basal metabolism. The hormone is responsible for regulating the rate of metabolism and storing energy.

Dosage: divided dose (morning / evening)

Beginners: 25-50 mcg / day 4-6 weeks

Advanced: 50-75 mcg / day 4-8 weeks


What is Cytomel and how is it used?

Cytomel is a prescription medicine used to treat symptoms of low thyroid hormone levels (hypothyroidism) and enlarged thyroid gland (nontoxic goiter), myxedema, and coma myxedema. Cytomel can be used alone or in combination with other medicines.

Cytomel belongs to a class of drugs called thyroid products.

What are the possible side effects of Cytomel?

Cytomel can cause serious side effects, including:

  • headache,
  • Irritability,
  • sleep problems
  • nervousness,
  • increased sweating
  • thermal intolerance,
  • diarrhea and
  • menstrual changes
  • Contact a doctor immediately if you experience any of the above symptoms.

The most common side effects of Cytomel are:

  • nausea
  • Tell your doctor if you have any side effects that bother you or that do not go away.
  • These are not all possible side effects of Cytomel. Contact your doctor or pharmacist for more information.
  • Ask your doctor for medical help regarding side effects. You can report side effects to the FDA at 1-800-FDA-1088.


Thyroid hormone medicines are natural or synthetic preparations that contain tetrabiodothyronine sodium (T4, levothyroxine) or triiodothyronine sodium (T3, liothyronine) or both. T4 and T3 are produced in the human thyroid gland by iodination and binding of the amino acid tyrosine. T4 contains four iodine atoms and is formed by the combination of two molecules of diiodothyrosine (DIT). T3 contains three iodine atoms and is formed by combining a DIT molecule with a monoiodothyrosine (MIT) molecule. Both hormones are stored in the thyroid colloid as thyroglobulin.

Thyroid hormone preparations are divided into two categories: (1) natural hormonal preparations derived from the thyroid gland of animals and (2) synthetic preparations. Herbal remedies include dried thyroid and thyroglobulin. The dried thyroid gland comes from domestic animals used by humans for food (cow or pig thyroid), and thyroglobulin comes from the pig thyroid gland. The United States Pharmacopoeia (USP) has standardized the total iodine content of natural preparations. Thyroid gland USP contains at least (NLT) 0.17 percent and not more (NMT) 0.23 percent iodine and thyroglobulin contains at least (NLT) 0.7 percent organically bound iodine. The iodine content is only an indirect indicator of actual hormonal biological activity.

Cytomel (liothyronine sodium) tablets contain liothyronine (L-triiodothyronine or LT3), a synthetic form of the natural thyroid hormone, and are available as the sodium salt.

The structural and empirical formulas and molecular weights of liothyronine sodium are shown below.


There are no reviews yet.

Be the first to review “Cytomel T3 (Lyothironine)”

Your email address will not be published. Required fields are marked *