What Is Tirosint?

Tirosint is a brand-name prescription medication containing Levothyroxine Sodium in a unique gel capsule formulation. It is manufactured by IBSA Pharma and is used as thyroid hormone replacement therapy for patients with hypothyroidism (underactive thyroid). It is also used as an adjunct to surgery and radioiodine therapy for the management of certain thyroid cancers.

What sets Tirosint apart from standard Levothyroxine tablets is its minimal inactive ingredients — containing only gelatin, glycerin, and water. This makes it an excellent option for patients with absorption issues, food sensitivities, or allergies to dyes and fillers found in conventional tablets.

How does Tirosint work?

Tirosint contains synthetic Levothyroxine (T4), which is chemically identical to the thyroxine naturally produced by the thyroid gland. Once absorbed, T4 is converted to the active hormone triiodothyronine (T3) in peripheral tissues. Thyroid hormones regulate metabolism, protein synthesis, growth, and development by binding to nuclear thyroid hormone receptors and influencing gene expression.

Tirosint's gel capsule formulation may offer more consistent absorption compared to tablets, particularly for patients who take other medications or have gastrointestinal conditions that affect absorption. It should be taken on an empty stomach, 30–60 minutes before breakfast.

What doses are available for Tirosint?

Tirosint Capsules (gel caps):

• 13 mcg
• 25 mcg
• 50 mcg
• 75 mcg
• 88 mcg
• 100 mcg
• 112 mcg
• 125 mcg
• 137 mcg
• 150 mcg
• 175 mcg
• 200 mcg

Tirosint-SOL (oral solution):

• 13 mcg, 25 mcg, 37.5 mcg, 44 mcg, 50 mcg, 62.5 mcg, 75 mcg, 88 mcg, 100 mcg, 112 mcg, 125 mcg, 137 mcg, 150 mcg, 175 mcg, 200 mcg

How hard is it to find Tirosint in stock?

Tirosint scores a 62 out of 100 on our findability scale, meaning it can be intermittently difficult to locate. As a brand-name, niche formulation of Levothyroxine in gel capsule form, Tirosint is not stocked as widely as standard Levothyroxine tablets. While it is not currently listed on the FDA drug shortage database, its specialty status means not every pharmacy carries it. Patients may need to call multiple pharmacies or use tools like Medfinder to locate it in stock nearby.

Broader Levothyroxine supply disruptions in 2024–2025 have also increased demand for alternative formulations like Tirosint, which can further strain availability at certain locations.

Who Can Prescribe Tirosint?

Tirosint can be prescribed by a variety of healthcare providers, including:

• Endocrinologists — thyroid specialists who most commonly prescribe Tirosint
• Primary Care Physicians — family medicine and internal medicine doctors
• OB/GYNs — for thyroid management during pregnancy
• Telehealth Providers — Tirosint prescriptions are available through telehealth consultations

If you're having trouble finding a prescriber, Medfinder can help you locate providers in your area.

Is Tirosint a controlled substance?

No, Tirosint is not a controlled substance. It is not scheduled by the DEA and does not have abuse potential. However, it does require a valid prescription from a licensed healthcare provider.

Common Side Effects of Tirosint

Most side effects of Tirosint are related to the dose being too high (overreplacement). Common side effects include:

• Temporary hair loss (usually resolves within a few months)
• Weight changes
• Appetite changes
• Headache
• Menstrual irregularities
• Heat sensitivity and sweating

Serious side effects that require immediate medical attention include rapid or irregular heartbeat, chest pain, shortness of breath, seizures, and signs of hyperthyroidism (excessive sweating, tremors, nervousness, insomnia, fever).

Important: Tirosint carries a boxed warning that thyroid hormones should NOT be used for weight loss. Excessive doses can cause serious or life-threatening toxicity.

Alternative Medications to Tirosint

If you cannot find or afford Tirosint, several alternatives are available:

• Synthroid (Levothyroxine Sodium Tablets) — the most widely prescribed brand-name Levothyroxine tablet, available at much lower cost
• Generic Levothyroxine Tablets — available from multiple manufacturers (Mylan, Sandoz, Lannett) for as low as $4–$20 for 30 tablets
• Levoxyl — another brand-name Levothyroxine tablet option
• Armour Thyroid — natural desiccated thyroid (porcine) containing both T4 and T3, preferred by some patients
• Authorized Generic Levothyroxine Capsules — made by YARAL Pharma, a lower-cost capsule alternative to brand Tirosint

Always consult your doctor before switching thyroid medications, as even small differences in formulation can affect your thyroid levels.

Drug Interactions with Tirosint

Tirosint can interact with several common medications and supplements. Key interactions include:

• Calcium supplements — reduce absorption; separate by at least 4 hours
• Iron supplements — reduce absorption; separate by at least 4 hours
• Antacids (aluminum-containing) — reduce absorption
• Proton pump inhibitors (Omeprazole, etc.) — may reduce absorption
• Cholestyramine and Colestipol — bind thyroid hormones; separate by 4 hours
• Warfarin — Levothyroxine increases anticoagulant effect; monitor INR closely
• Carbamazepine, Phenytoin, Rifampin — increase thyroid hormone metabolism
• Estrogen-containing contraceptives — may require Tirosint dose adjustment

Also avoid taking Tirosint with soy products, walnuts, grapefruit juice, or high-fiber foods, which may decrease absorption. Tirosint's gel capsule formulation may be less affected by coffee than standard tablets.

Final Thoughts on Tirosint

Tirosint is a premium Levothyroxine formulation that offers distinct advantages for patients with absorption concerns, sensitivity to inactive ingredients, or inconsistent results with standard tablets. While its higher cost and niche market status can make it harder to find and more expensive than generic alternatives, programs like the Tirosint Copay Savings Card ($25/month) and Tirosint Direct ($65/month) can significantly reduce out-of-pocket costs.

If you're struggling to find Tirosint in stock at your local pharmacy, try using Medfinder to search for availability near you without having to call around. And always talk to your doctor before making any changes to your thyroid medication regimen.