Prescription medicine
Liothyronine Brand names: Cytomel, Liomny
Liothyronine (Cytomel) is a prescription medicine with an FDA approval on record since 1956. FDA's NDC Directory lists it from 17 generic labelers, and pharmacies paid $0.294 per liothyronine sod 25 mcg tablet in the October 7, 2026 NADAC survey.
- Generic listed
- Boxed warning
Check it at the source: the liothyronine FDA label on DailyMed (effective June 4, 2026, Mylan Pharmaceuticals Inc.); the NDA 10379 record on Drugs@FDA; every liothyronine label on DailyMed.
Highlights of the record
FDA label of June 4, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS •.
Thyroid hormones, including LIOTHYRONINE SODIUM, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss.
In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.
Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects [see Adverse Reactions (6), Drug Interactions (7.7), and Overdosage (10) ]. WARNING: NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS See full prescribing information for complete boxed warning.
Thyroid hormones, including liothyronine sodium, should not be used for the treatment of obesity or for weight loss.
Doses beyond the range of daily hormonal requirements may produce serious or even life-threatening manifestations of toxicity ( 6 , 7.7 , 10 ).
Used for
From the label: indications and usageLiothyronine sodium is an L-triiodothyronine (T3) indicated for:
Hypothyroidism: As replacement in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism ( 1.1 )
Pituitary Thyroid-Stimulating Hormone (TSH) Suppression: As an adjunct to surgery and radioiodine therapy in the management of well-differentiated thyroid cancer ( 1.2 )
Thyroid Suppression Test: A
Forms and strengths
Tablet; injection (solution).
On the market
- Earliest approval on file
- May 8, 1956 Cytomel, King Pharms; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 10 first January 25, 1982; 7 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 19 of which 17 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- $0.294 per tablet Liothyronine sod 25 mcg tablet
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- 11 since 2013 0 Class I among all firms' recalls; latest December 4, 2023; 3 more by firms not listed as its makers
- FAERS reports
- 8,659 through July 30, 2026
What is liothyronine used for?
From the label: indications and usageLiothyronine sodium is an L-triiodothyronine (T3) indicated for:
Hypothyroidism: As replacement in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism ( 1.1 )
Pituitary Thyroid-Stimulating Hormone (TSH) Suppression: As an adjunct to surgery and radioiodine therapy in the management of well-differentiated thyroid cancer ( 1.2 )
Thyroid Suppression Test: As a diagnostic agent in suppression tests to differentiate suspected mild hyperthyroidism or thyroid gland autonomy ( 1.3 ) Limitations of Use: - Not indicated for suppression of benign thyroid nodules and nontoxic diffuse goiter in iodine-sufficient patients. […]
Conditions named in the indications of liothyronine's FDA labels, with every medicine labeled for each:
FDA pharmacologic class: l-Triiodothyronine.
Source: FDA drug label (Liothyronine Sodium), NDA010379 (King Pharms), as published by Mylan Pharmaceuticals Inc., effective June 4, 2026 (SPL set 115a84c2-0126-4dd7-816e-1873875f1e49), via openFDA; the full label on DailyMed
Is there a generic for liothyronine (Cytomel)?
The FDA approved the first generic liothyronine on January 25, 1982. 10 generic applications are approved; 7 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists liothyronine from 17 labelers under a generic (ANDA) application and from 1 brand labeler. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1956 earliest approval on file
- 1982 first generic approved
- red ticks recalls
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for liothyronine (Cytomel)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $0.294 per Liothyronine sod 25 mcg tablet, down 14% from $0.343 on October 8, 2025. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Liothyronine sod 5 mcg tablet (generic)
- Cytomel 5 mcg tablet (brand)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Liomny 25 mcg tablet | Generic | $0.294 per tablet | $8.82 | n/a |
| Liomny 5 mcg tablet | Generic | $0.202 per tablet | $6.07 | n/a |
| Liomny 50 mcg tablet | Generic | $0.362 per tablet | $10.87 | n/a |
| Liothyronine sod 25 mcg tablet | Generic | $0.294 per tablet | $8.82 | -14% |
| Liothyronine sod 5 mcg tablet | Generic | $0.202 per tablet | $6.07 | -21% |
| Liothyronine sod 50 mcg tablet | Generic | $0.362 per tablet | $10.87 | -23% |
| Cytomel 25 mcg tablet | Brand | $0.533 per tablet | $15.99 | +5% |
| Cytomel 5 mcg tablet | Brand | $0.386 per tablet | $11.57 | +5% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
Has liothyronine been recalled?
The FDA's Enforcement Report lists 14 recalls naming liothyronine since 2013: 0 Class I (the most serious), 13 Class II, 1 Class III; 0 still ongoing. 3 of them are by firms that FDA's NDC Directory does not list as a maker of liothyronine and that hold no application for it in Drugs@FDA, such as compounding pharmacies or bulk-ingredient suppliers; the recall notice names the product recalled. A recall names products and lots, not every product of the medicine.
| Started | Class | Company | Reason |
|---|---|---|---|
| December 4, 2023 | Class II | SUN PHARMACEUTICAL INDUSTRIES INC | Failed Impurities/Degradation Specifications |
| October 20, 2023 | Class II | SUN PHARMACEUTICAL INDUSTRIES INC | Failed Impurities/Degradation Specifications. |
| December 18, 2019 | Class II | MPRX, Inc. dba Medical Park Pharmacy not a listed maker | Labeling: Incorrect or missing lot and/or expiration date. Products were compounded using expired components. |
| November 16, 2017 | Class II | KRS Global Biotechnology, Inc not a listed maker | Labeling: Incorrect or Missing Lot and/or Exp Date: Beyond Use Date (BUD) exceed the BUD/EXP of at least one ingredient used to make final product. |
| November 9, 2017 | Class II | Mayne Pharma Inc | Failed Dissolution Specifications. |
| November 14, 2014 | Class II | Attix Pharmaceuticals | Penicillin Cross Contamination: All lots of all products repackaged and distributed between 01/05/12 and 02/12/15 are being recalled because they were … |
| April 22, 2014 | Class II | SigmaPharm Laboratories LLC | Cross Contamination with Other Products: Four lots of Liothyronine Sodium Tablets, USP 5 mcg are being recalled due to the finding of a potential carryover of … |
| July 2, 2013 | Class II | Aidapak Services, LLC | Labeling: Label Mixup; LIOTHYRONINE SODIUM Tablet, 5 mcg may be potentially mislabeled as HYDROCHLOROTHIAZIDE, Tablet, 12.5 mg, NDC 16729018201, Pedigree … |
Source: FDA Enforcement Report (drug recalls) via openFDA, through October 8, 2026
What does the liothyronine label say about other medicines?
The liothyronine label names 18 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Amiodarone | drug interactions | Other drugs: Amiodarone; Amiodarone inhibits peripheral conversion of levothyroxine (T4) to triiodothyronine (T3) and may cause isolated biochemical changes (increase in serum free-T4, and decreased or normal free-T3) in clinically euthyroid patients. |
| Amitriptyline | drug interactions | Concurrent use of tricyclic (e.g., amitriptyline) or tetracyclic (e.g., maprotiline) antidepressants and liothyronine sodium may increase the therapeutic and toxic effects of both drugs, possibly due to increased receptor sensitivity to catecholamines. |
| Asparaginase | drug interactions | Androgens/Anabolic Steroids Asparaginase Glucocorticoids Slow-Release Nicotinic Acid These drugs may decrease serum TBG concentration. |
| Carbamazepine | drug interactions | Carbamazepine Furosemide (>80 mg IV) Heparin Hydantoins Non-Steroidal Anti-inflammatory Drugs Fenamates These drugs may cause protein binding site displacement. |
| Dexamethasone | drug interactions | Glucocorticoids (e.g., Dexamethasone ≥4 mg/day) Short-term administration of large doses of glucocorticoids may decrease serum T3 concentrations by 30% with minimal change in serum T4 levels. |
| Furosemide | drug interactions | Carbamazepine Furosemide (>80 mg IV) Heparin Hydantoins Non-Steroidal Anti-inflammatory Drugs Fenamates These drugs may cause protein binding site displacement. |
| Heparin | drug interactions | Carbamazepine Furosemide (>80 mg IV) Heparin Hydantoins Non-Steroidal Anti-inflammatory Drugs Fenamates These drugs may cause protein binding site displacement. |
| Imatinib | drug interactions | Concurrent use of tyrosine-kinase inhibitors such as imatinib may cause hypothyroidism. |
| Ketamine | drug interactions | Concurrent use of ketamine and liothyronine sodium may produce marked hypertension and tachycardia. |
| Levothyroxine | drug interactions | Other drugs: Amiodarone; Amiodarone inhibits peripheral conversion of levothyroxine (T4) to triiodothyronine (T3) and may cause isolated biochemical changes (increase in serum free-T4, and decreased or normal free-T3) in clinically euthyroid patients. |
| Methadone | drug interactions | Drug or Drug Class: Clofibrate Estrogen-containing oral contraceptives Estrogens (oral) Heroin/Methadone 5-Fluorouracil Mitotane Tamoxifen; Effect: These drugs may increase serum thyroxine-binding globulin (TBG) concentration. |
| Mitotane | drug interactions | Drug or Drug Class: Clofibrate Estrogen-containing oral contraceptives Estrogens (oral) Heroin/Methadone 5-Fluorouracil Mitotane Tamoxifen; Effect: These drugs may increase serum thyroxine-binding globulin (TBG) concentration. |
| Phenobarbital | drug interactions | Drug or Drug Class Effect Phenobarbital Rifampin Phenobarbital has been shown to reduce the response to thyroxine. |
| Phenytoin | drug interactions | … T4-binding sites on TBG, prealbumin, and albumin, so that a single high dose can acutely lower the total T4 level. Phenytoin and carbamazepine reduce serum protein binding of thyroid hormones, and total and FT4 may be reduced by 20% to 40%, but most patients have normal serum TSH levels and are clinically euthyroid. … |
Every other medicine the liothyronine label names
| Medicine named | Section | What the label says |
|---|---|---|
| Propranolol | drug interactions | Beta-adrenergic antagonists (e.g., Propranolol >160 mg/day); In patients treated with large doses of propranolol (>160 mg/day), T3 and T4 levels change, TSH levels remain normal, and patients are … |
| Rifampin | drug interactions | Drug or Drug Class Effect Phenobarbital Rifampin Phenobarbital has been shown to reduce the response to thyroxine. |
| Sertraline | drug interactions | Administration of sertraline in patients stabilized on liothyronine sodium may result in increased liothyronine sodium requirements. |
| Tamoxifen | drug interactions | Drug or Drug Class: Clofibrate Estrogen-containing oral contraceptives Estrogens (oral) Heroin/Methadone 5-Fluorouracil Mitotane Tamoxifen; … |
Source: FDA drug label (Liothyronine Sodium), NDA010379 (King Pharms), as published by Mylan Pharmaceuticals Inc., effective June 4, 2026 (SPL set 115a84c2-0126-4dd7-816e-1873875f1e49), via openFDA; the full label on DailyMed
What do FAERS reports show for liothyronine?
The FDA Adverse Event Reporting System holds 8,659 reports that list liothyronine among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 205 are coded as a death and 1,491 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as liothyronine?
1 other medicine is given the same way (oral) and in the same FDA class as liothyronine or labeled mainly for the same use (hypothyroidism), the same class first. Hypothyroidism lists all 2 medicines labeled for it, by any route. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Levothyroxine | Hypothyroidism | 31 labelers | $0.0588 per tablet 112 mcg tablet | No current entry |
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
How does liothyronine compare with medicines for the same use?
1 side-by-side page set liothyronine beside a medicine whose label shares a use: approvals, generics, pharmacy cost, warnings and supply.
What next?
- Liothyronine side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other