What Is Adthyza?

Adthyza was a natural desiccated thyroid (NDT) medication manufactured by Azurity Pharmaceuticals (formerly Silvergate Pharmaceuticals). It contained both levothyroxine (T4) and liothyronine (T3) derived from porcine (pig) thyroid glands. Adthyza was prescribed for the treatment of hypothyroidism — a condition where the thyroid gland doesn't produce enough thyroid hormones.

Adthyza was also used for pituitary TSH suppression in patients with thyroid nodules or multinodular goiter, and as a diagnostic agent in thyroid suppression tests. Some patients and providers preferred NDT products like Adthyza because they provide both T4 and T3 hormones, rather than T4 alone as with synthetic levothyroxine.

Note: Adthyza was discontinued in late November 2025 and is no longer available.

How does Adthyza work?

Adthyza works by providing exogenous (external) thyroid hormones to replace what the body cannot produce on its own. It contains two key hormones:

• T4 (Levothyroxine) — A long-acting thyroid hormone that serves as a reservoir. The body converts T4 into the active T3 form in peripheral tissues as needed.
• T3 (Liothyronine) — The biologically active thyroid hormone that directly regulates metabolism, energy production, heart rate, and body temperature.

Unlike synthetic levothyroxine (Synthroid), which provides only T4, Adthyza supplied both hormones in a natural ratio derived from porcine thyroid tissue. This was preferred by some patients who reported feeling better on combined T4/T3 therapy compared to T4-only treatment.

The medication should be taken once daily on an empty stomach, 30–60 minutes before breakfast, to ensure optimal absorption.

What doses were available for Adthyza?

• ¼ grain / 16.25 mg (9.5 mcg T4 + 2.25 mcg T3)
• ½ grain / 32.5 mg (19 mcg T4 + 4.5 mcg T3)
• 1 grain / 65 mg (38 mcg T4 + 9 mcg T3)
• 1½ grains / 97.5 mg (57 mcg T4 + 13.5 mcg T3)
• 2 grains / 130 mg (76 mcg T4 + 18 mcg T3)

Each tablet contained a fixed ratio of T4 (levothyroxine) and T3 (liothyronine) derived from porcine thyroid glands.

How hard is it to find Adthyza in stock?

Adthyza has been discontinued as of late November 2025 and is no longer being manufactured or distributed. Azurity Pharmaceuticals ceased production, and remaining inventory has been depleted from pharmacy shelves. Patients who relied on Adthyza will need to transition to an alternative natural desiccated thyroid (NDT) product such as Armour Thyroid or NP Thyroid, or discuss switching to synthetic thyroid hormones like Levothyroxine with their prescriber.

The broader NDT market has experienced significant disruptions in recent years, with Nature-Throid and WP Thyroid also discontinued and NP Thyroid previously recalled for sub-potency issues. Armour Thyroid remains the primary widely-available NDT brand.

Who Can Prescribe Adthyza?

Adthyza could be prescribed by a range of healthcare providers, including:

• Endocrinologists — Specialists in thyroid and hormonal disorders, most commonly involved in managing complex thyroid conditions
• Internal Medicine physicians — Often manage hypothyroidism as part of overall patient care
• Family Medicine physicians — Frequently diagnose and treat hypothyroidism in primary care settings
• Integrative and Functional Medicine practitioners — Often prefer NDT products for patients seeking natural hormone replacement
• Naturopathic physicians — May recommend NDT as part of a holistic treatment approach (prescribing authority varies by state)

Telehealth providers can also prescribe thyroid medications including NDT products, making it convenient for patients in areas with limited specialist access.

Is Adthyza a controlled substance?

No, Adthyza is not a controlled substance. It is not scheduled by the DEA and does not carry restrictions associated with controlled medications. It can be prescribed with a standard prescription and does not require special prescribing authority or triplicate forms.

However, Adthyza does carry an FDA boxed warning stating that thyroid hormones should not be used for weight loss. In euthyroid (normal thyroid function) patients, doses within the normal range are ineffective for weight reduction, and larger doses can cause serious or life-threatening toxicity.

Common Side Effects of Adthyza

• Temporary hair loss (especially in children during the first months of treatment)
• Headache
• Mild diarrhea
• Changes in appetite
• Weight changes
• Menstrual irregularities
• Nervousness or irritability

Seek immediate medical attention if you experience chest pain, rapid or irregular heartbeat, shortness of breath, excessive sweating, severe tremor, or signs of thyroid toxicity. Long-term overtreatment can lead to bone density loss and cardiovascular complications.

Alternative Medications to Adthyza

Since Adthyza has been discontinued, patients will need to transition to an alternative. Options include:

• Armour Thyroid (NDT by AbbVie) — The most well-known desiccated thyroid product, widely available at $35–$43/month. Most direct substitute for Adthyza.
• NP Thyroid (NDT by Acella Pharmaceuticals) — Similar NDT with fewer inactive ingredients, $24–$40/month. Previously recalled for sub-potency but returned to market.
• Levothyroxine (Synthroid, Levoxyl, Tirosint) — Synthetic T4 only, the standard first-line treatment for hypothyroidism. Widely available and affordable at $4–$30/month for generic.
• Liothyronine (Cytomel) — Synthetic T3 that can be combined with Levothyroxine to mimic the T4/T3 ratio found in NDT products, $10–$40/month for generic.

Talk to your prescriber about which alternative is best for your specific situation. Dose conversion between NDT products and synthetic hormones requires careful medical supervision and follow-up lab work.

Drug Interactions with Adthyza

Adthyza had several important drug interactions to be aware of:

• Warfarin and anticoagulants — Thyroid hormones can increase bleeding risk; INR monitoring and dose adjustments may be needed
• Insulin and diabetes medications — Thyroid hormones affect blood sugar levels; diabetes medication doses may need adjustment
• Cholestyramine and Colestipol — Significantly reduce thyroid hormone absorption; take at least 4 hours apart
• Oral estrogens and birth control pills — Can increase thyroid-binding globulin, reducing free hormone levels
• Calcium supplements and antacids — Reduce absorption; separate by at least 4 hours
• Iron supplements — Reduce absorption; take at least 4 hours apart
• Amiodarone — Contains iodine and can affect thyroid function
• Lithium — May cause hypothyroidism and alter thyroid hormone levels

Always take Adthyza on an empty stomach, 30–60 minutes before eating, and separate from calcium, iron, and antacids by at least 4 hours for optimal absorption.

Final Thoughts on Adthyza

Adthyza was a natural desiccated thyroid medication that provided an important option for hypothyroid patients who preferred combined T4/T3 therapy from a porcine source. Unfortunately, Adthyza was discontinued in late November 2025 by Azurity Pharmaceuticals, and it is no longer available at pharmacies.

If you were taking Adthyza, work closely with your healthcare provider to transition to an alternative thyroid medication. Armour Thyroid is the most direct NDT substitute, while Levothyroxine remains the widely-available standard treatment. Do not stop taking thyroid medication abruptly — an unmanaged transition can lead to serious health consequences.

Use Medfinder to check availability of alternative thyroid medications at pharmacies near you.