Natural Desiccated Thyroid (NDT): quick practical guide

If you’re hearing about natural desiccated thyroid (NDT) and wondering if it’s right for you, this page cuts to the chase. NDT is a prescription thyroid replacement made from pig thyroid glands. It supplies both T4 and T3 hormones, so some people feel better on it than on synthetic levothyroxine. But it’s not a one-size-fits-all fix—there are pros, cons, and real safety steps to follow.

How NDT differs from levothyroxine

Levothyroxine gives only T4. Your body must convert T4 into the active T3. NDT includes both hormones, so it can help people who don’t convert well. That can mean faster symptom relief for fatigue, brain fog, or cold intolerance. However, because NDT contains T3, it can cause palpitations, anxiety, or bone loss if dose isn’t right. Doctors watch labs and symptoms closely when switching or starting NDT.

Brands you’ll see include Armour, Nature-Throid, and WP Thyroid. Doses are often written in grains or milligrams. If you switch brands, expect small potency shifts—so labs and symptoms should guide adjustments, not just milligrams on the bottle.

Practical tips for starting and monitoring

1) Get a proper diagnosis and prescription. NDT is prescription-only in many places. 2) Baseline tests: TSH, free T4, free T3, plus a clinical review of symptoms. 3) Start low and reassess. Most clinicians wait 6–8 weeks after a dose change before rechecking labs. 4) Watch for signs of too much thyroid: racing heart, trouble sleeping, weight loss, or bone pain. If these appear, contact your provider quickly.

Special situations matter. If you’re pregnant, trying to conceive, or have heart disease, NDT may not be recommended. Pregnancy requires tight hormone control and often favors synthetic preparations because they’re consistent and well studied in pregnancy. Older adults and people with osteoporosis or arrhythmias also need extra caution.

Drug and food interactions matter. Iron, calcium, and some supplements can block absorption—take NDT at least 4 hours apart from these. Estrogen and some medications can change thyroid hormone needs. Tell your provider about all medicines and supplements you use.

Buying and affordability: Only use licensed pharmacies. If you shop online, verify the pharmacy license, require a prescription, and avoid deals that look too good to be true. Consistency matters: stick with the same brand and supplier when possible to avoid unexpected dose shifts.

Want more reading? Check articles on switching therapies, monitoring schedules, and safe pharmacy practices on this site. And remember: symptom relief is important, but steady lab monitoring and a clinician’s guidance keep treatment safe and effective.