Desiccated thyroid (NDT): what it is and who it helps

Desiccated thyroid, often called NDT (natural desiccated thyroid), is a thyroid replacement made from dried pig thyroid glands. It contains both T4 and T3 hormones, plus small amounts of other thyroid components. Some people prefer it because they feel better on a combination product versus levothyroxine (T4) alone.

This page gives straight answers: how NDT works, basic dosing ideas, what to watch for, and practical next steps if you’re considering it.

Why some people choose NDT

People pick NDT for a few common reasons: persistent symptoms on levothyroxine (fatigue, brain fog, low mood), a desire for a more “natural” product, or past success with combination therapy. NDT supplies T3 as well as T4, so it can raise free T3 faster than levothyroxine alone.

Keep one thing in mind: T3 can cause jitteriness, heart palpitations, or sleep trouble if the dose is too high. That’s why careful dosing and monitoring are essential.

Dosing, switching, and monitoring — practical tips

There’s no one-size-fits-all dose. A commonly used conversion: roughly 1 grain (about 60–65 mg) NDT equals about 100 mcg levothyroxine—this is an approximation used by many clinicians. When switching, providers usually lower the total thyroid dose slightly and check labs after 6–8 weeks.

What to test: TSH, free T4, and free T3. TSH remains the standard marker, but free T3 helps check how you feel on NDT. Expect to repeat labs 6–8 weeks after a change, then every 3–6 months until stable.

If you notice palpitations, new anxiety, weight loss, or trouble sleeping after starting NDT, contact your prescriber. Those signs can mean your thyroid dose is too high.

Special situations: pregnancy and heart disease change the rules. Levothyroxine is usually preferred in pregnancy because its dose is predictable and easier to adjust. People with heart disease need lower starting doses and slower increases.

Quality matters. Different brands (Armour, Nature-Throid, WP Thyroid) vary slightly in potency and fillers. If you use NDT, try to stay with the same reliable brand and buy from reputable pharmacies. Some people use compounding pharmacies for customized doses—ask about batch testing and quality control.

Want to try NDT? Talk with a clinician who understands thyroid management. Bring a record of your current doses, symptoms, and recent lab results. Expect lab follow-ups and small dose changes until your symptoms and labs match.

If you want more detail on switching between thyroid meds, our guide on switching thyroid medications explains exact conversion steps, monitoring checklists, and real patient examples to help you and your provider plan a safe change.

Desiccated thyroid can help some people feel better, but it needs careful handling. Use sensible doses, get routine labs, and work with a clinician familiar with NDT to get results without side effects.