Thyroid extract — also called desiccated thyroid extract (DTE) or natural desiccated thyroid (NDT) — is made from the dried thyroid glands of pigs (porcine) or cows (bovine). Unlike the most commonly prescribed synthetic thyroid drug, which contains only T4, thyroid extract naturally contains both T4 and T3, plus smaller thyroid hormones and supportive proteins found in a real thyroid gland. It has been used medically for over 125 years and was the standard thyroid treatment before synthetic hormones became widely available in the 1960s.

Your thyroid gland makes several hormones, but the two most important are T4 (a storage hormone) and T3 (the active hormone your cells actually use for energy, mood, metabolism, and brain function). Thyroid extract delivers both, which some people find more effective than T4-only therapy because not everyone converts T4 to T3 efficiently on their own. The included T3 acts faster and more directly, which may explain why some people report better symptom relief compared to synthetic T4 alone.

Thyroid extract is most commonly available as standardized tablets (brand names include Armour Thyroid, NP Thyroid, and Nature-Throid) dosed in grains (1 grain = 60–65 mg) or milligrams. Compounding pharmacies can also prepare custom doses in capsule form for patients with specific needs or sensitivities. Prescription is required in most countries.

• Hypothyroidism (underactive thyroid)
• Fatigue and low energy
• Brain fog and poor concentration
• Depression and low mood
• Weight gain and slow metabolism
• Hair thinning and hair loss
• Cold intolerance
• Constipation
• Low libido
• Dry skin

• Cardiovascular complications associated with undertreated hypothyroidism
• Cognitive decline linked to chronic low thyroid function

Thyroid extract is a prescription glandular product — you cannot get it from food. However, certain nutrients are essential for your thyroid to work properly and can support overall thyroid health alongside treatment. Iodine-rich foods (seaweed, wild-caught fish, dairy) provide the raw material for thyroid hormone production. Selenium-rich foods (Brazil nuts — just 1-2 per day — and sardines) are critical for converting T4 into active T3. Zinc-rich foods (pumpkin seeds, grass-fed beef, chickpeas) support thyroid hormone synthesis. Iron-rich foods (lentils, red meat, spinach) are important because iron deficiency impairs thyroid function. On the flip side, large amounts of raw cruciferous vegetables (kale, broccoli, cabbage) can mildly suppress thyroid hormone production if eaten in very high quantities — cooking reduces this effect. Soy products can interfere with thyroid hormone absorption if consumed close to taking your dose, so spacing is wise. Foods to limit: Large amounts of raw cruciferous vegetables (kale, broccoli, bok choy) — cook them to reduce thyroid-suppressing compounds, Soy products taken within 4 hours of your thyroid dose — can reduce absorption, High-fiber foods, calcium-fortified foods, and coffee taken at the same time as your dose — can impair absorption, Highly processed foods high in refined sugar — worsen inflammation and metabolic stress that burden thyroid function.

• Racing or pounding heartbeat (palpitations) — usually a sign the dose is too high
• Anxiety, nervousness, or feeling wired
• Excessive sweating or heat intolerance
• Tremor or shakiness
• Insomnia or difficulty sleeping
• Unintended weight loss
• Diarrhea or loose stools
• Headache
• Chest discomfort — seek medical attention immediately
• Bone density loss with long-term over-replacement
• Atrial fibrillation risk with excessive long-term T3 levels (especially in older adults)
• Allergic reactions (rare) — possible sensitivity to porcine or bovine proteins

• Recommended daily: Starting dose is typically 30 mg (½ grain) daily, with gradual increases every 4–6 weeks based on symptoms and labs. Most adults stabilize between 60–120 mg (1–2 grains) daily, though optimal dose varies significantly by individual. Always prescribed and monitored by a licensed healthcare provider.
• Best time of day: Most commonly taken in the morning on an empty stomach, 30–60 minutes before eating or coffee. Some practitioners split the dose (morning and early afternoon) to smooth out T3 delivery throughout the day, since T3 has a shorter half-life than T4.
• With or without food: Take on an empty stomach for best absorption. Food — especially high-fiber, calcium-rich, or fatty foods — can significantly reduce absorption. Wait at least 30–60 minutes before eating.
• Time to effect: Some patients notice initial symptom improvements within 2–4 weeks; full optimization and stable hormone levels typically take 3–6 months of careful titration.
• How long to take it: Thyroid extract is typically a long-term or lifelong treatment for hypothyroidism, not a short-term supplement. Do not stop suddenly without medical guidance. Dose adjustments are made over time based on TSH, free T3, free T4, and how the patient feels.