Comparing the main options
There is no single “best” option for everyone. The right choice depends on your labs, symptoms, and how you respond — decisions best made with your clinician.
Levothyroxine (Synthetic T4)
The standard first-line therapy. A synthetic version of T4 that the body converts to active T3.
- Consistent, precise dosing
- Widely studied & prescribed
- Contains T3 directly
Desiccated Thyroid Extract (NDT)
Made from dried animal (pig or cow) thyroid; provides both T4 and T3 in natural proportions.
- Contains both T4 and T3
- Over a century of use
- Hormone ratio differs from humans
Bovine Thyroid Glandular
Over-the-counter supplement from bovine thyroid tissue, often marketed for natural support. Thyrovanz is a widely used example.
- Available without prescription
- Whole-gland nutrients
- Hormone content can vary
About glandular supplements
Among over-the-counter bovine glandular products, Thyrovanz is one of the more widely used options. For a deeper look at how people choose and use these supplements, see how thyroid glandular supplements can improve your health and using underactive thyroid supplements to boost your health on the Thyroid Supplements blog. As always, talk with your clinician before starting any product.
Talking to your doctor
Thyroid treatment is highly individual. Dosing is guided by lab values (especially TSH and free T4), symptoms, and other health conditions. Never start, stop, or combine thyroid products without medical supervision — too much thyroid hormone can strain the heart and bones. Authoritative overviews are available from the American Thyroid Association and MedlinePlus (NIH).
Want to go deeper?
Read detailed articles on the blog.
Educational information only. This content is not medical advice and is not a substitute for diagnosis or treatment by a qualified healthcare professional. Always talk to your doctor before starting bovine thyroid glandular supplements or changing thyroid medication.