Two medicines, side by side
Liothyronine vs propranolol
Liothyronine is labeled for hypothyroidism; propranolol for high blood pressure, angina and atrial fibrillation. Their labels share no use, so they are not alternatives to each other. Drugs@FDA records approvals of liothyronine since 1956 and of propranolol since 1967. Pharmacies paid $0.294 per liothyronine sod 25 mcg tablet and $0.0493 per propranolol 20 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, liothyronine is a l-triiodothyronine and propranolol a beta-adrenergic blocker.
Check it at the source: the liothyronine FDA label on DailyMed (effective June 4, 2026); the propranolol FDA label on DailyMed (effective January 15, 2026).
Highlights of the liothyronine record
Liothyronine (Cytomel) · label of June 4, 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.
Used for
From the label: indicationsLiothyronine 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: […]
On the market
- Earliest approval on file
- May 8, 1956
- Generic labelers
- 17 labelers
- Pharmacy cost
- $0.294 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 11
Highlights of the propranolol record
Propranolol (Inderal) · label of January 15, 2026
Used for
From the label: indicationsHypertension Propranolol hydrochloride tablets are indicated in the management of hypertension. It may be used alone or used in combination with other antihypertensive agents, particularly a thiazide diuretic. Propranolol hydrochloride tablets are not indicated in the management of hypertensive emergencies. […]
On the market
- Earliest approval on file
- November 13, 1967
- Generic labelers
- 42 labelers
- Pharmacy cost
- $0.0493 per tablet
Supply and safety
- Shortage
- In shortage
- Recalls
- 4
Source: FDA drug labels via openFDA (Liothyronine label of June 4, 2026, Propranolol label of January 15, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do liothyronine and propranolol differ on the record?
In FDA's classes, liothyronine is a l-triiodothyronine and propranolol a beta-adrenergic blocker.
How each works, in its label's words: Liothyronine, “Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA.”; Propranolol, “Mechanism of Action The mechanism of the antihypertensive effect of propranolol has not been established.”
Half-life, in each label's words: Liothyronine, “The biological half-life is about 2-1/2 days.”; Propranolol, “The plasma half-life of propranolol is from 3 to 6 hours.”
Only the liothyronine label carries a boxed warning.
Generics: liothyronine since 1982; propranolol since 1985 (Drugs@FDA).
| Liothyronine | Propranolol | |
|---|---|---|
| Labeled for | Hypothyroidism | High blood pressure, Angina, Atrial fibrillation, Migraine |
| Pharmacologic class | l-Triiodothyronine | beta-Adrenergic Blocker |
| How it works (label) | Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. | Mechanism of Action The mechanism of the antihypertensive effect of propranolol has not been established. |
| Half-life (label) | The biological half-life is about 2-1/2 days. | The plasma half-life of propranolol is from 3 to 6 hours. |
| Earliest approval on file (Drugs@FDA) | May 8, 1956 | November 13, 1967 |
| First generic approved | January 25, 1982 | July 30, 1985 |
| Generic labelers (NDC) | 17 labelers | 42 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.294 per tablet (Liothyronine sod 25 mcg tablet) | $0.0493 per tablet (Propranolol 20 mg tablet) |
| 12-month price change | -14% | -17% |
| Boxed warning | Yes | No |
| Shortage now | No current entry | In shortage |
| Recalls recorded | 11 | 4 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 8,659 | 71,660 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
Liothyronine label, drug interactionsBeta-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 clinically euthyroid. Actions of particular beta-adrenergic antagonists may be impaired when a hypothyroid patient is converted to the euthyroid state.
Source: FDA drug labels via openFDA
What next?
- Alternatives to liothyronine
- every medicine labeled for the same conditions