levothyroxine vs thyroid (desiccated)
Side-by-side comparison of levothyroxine and thyroid (desiccated) Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Synthroid, Levoxyl, Tirosint
Armour Thyroid, Nature-Throid
Levothyroxine is a medicine that replaces a hormone normally made by your thyroid gland. It is used when the thyroid doesn't make enough hormone on its own.
Armour Thyroid is a natural thyroid hormone medicine. It helps your body when it doesn't make enough thyroid hormone on its own.
This medicine treats hypothyroidism, a condition where the thyroid gland doesn't make enough thyroid hormone. It can be used in adults and children, even newborns. Levothyroxine can also be used after surgery and radioiodine therapy for thyroid cancer to help lower thyroid-stimulating hormone (TSH) levels.
This medicine treats hypothyroidism, a condition where your thyroid gland doesn't make enough thyroid hormone. It can help with different types of hypothyroidism, like cretinism, myxedema, and ordinary hypothyroidism. It can also be used to manage certain types of goiters and thyroid cancer by suppressing TSH.
Levothyroxine provides a synthetic form of thyroxine (T4), which is the main hormone produced by the thyroid gland. Your body converts T4 into triiodothyronine (T3), the active form of the hormone. By providing T4, levothyroxine helps restore normal thyroid hormone levels in your body.
Armour Thyroid provides thyroid hormones that your body needs to function properly. It contains both T4 (levothyroxine) and T3 (liothyronine). These hormones help regulate your metabolism, energy levels, and overall growth and development.
- • Fatigue
- • Increased appetite
- • Weight loss
- • Feeling hot
- • Headache
No common side effects listed.
- Tiredness 25,847
- Feeling sick to your stomach 22,021
- Medicine not working 20,559
- Head pain 18,798
- Loose stools 18,178
No adverse event reports.
Thyroid hormones, including levothyroxine, should not be used for weight loss or to treat obesity. Using high doses can cause serious and life-threatening side effects, especially when taken with stimulant medicines.
Thyroid hormones should not be used for weight loss. Using high doses of thyroid hormone, especially with other stimulants, can cause serious and life-threatening problems.
Tell your doctor if you are pregnant or plan to become pregnant. Your levothyroxine dose may need to be adjusted during pregnancy. Levothyroxine passes into breast milk, but it is not expected to harm the baby.
Armour Thyroid can be used during pregnancy. Talk to your doctor, as your dosage needs may change during pregnancy.
How to Read This levothyroxine vs thyroid (desiccated) Comparison
levothyroxine is classified in the Thyroid Hormone drug class, while thyroid (desiccated) sits within the Thyroid Hormone (Natural) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, levothyroxine has 105,403 submissions while thyroid (desiccated) has 0. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between levothyroxine and thyroid (desiccated) — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.