• Low energy, feeling cold, weight gain or difficulty losing weight
• Dry skin, hair loss, brittle nails
• Constipation, slower digestion
• Muscle cramps, joint aches
• Low mood, slowed thinking, memory complaints

Related topics

• Constipation · Dry Skin/Eyes · Depression (Late Life)
• Fatigue · High Cholesterol

Primary hypothyroidism

• TSH is high and Free T4 is low (or low-normal)
• “Subclinical”: TSH high with normal Free T4; decisions depend on symptoms, age, heart risk, and TSH level

Central hypothyroidism

• TSH low/normal with low Free T4 → pituitary/hypothalamic cause
• Needs specialist evaluation; TSH not reliable to monitor therapy

What it is

Levothyroxine (T4) is identical to the main thyroid hormone your body produces. Your tissues convert some T4 to T3 as needed.

Starting doses (older adults)

• Lower starting doses are common, especially with heart disease
• Slow titration helps avoid palpitations or angina

Timing

• Take on an empty stomach with water, same time each day
• Wait at least 30–60 minutes before breakfast (or take at bedtime 3+ hours after last meal)

Common blockers (separate by 4 hours)

• Calcium, iron, magnesium, multivitamins
• Cholestyramine, sucralfate, some fiber supplements
• Soy or very high-fiber meals can reduce absorption

Medicine interactions (examples)

• Warfarin (INR can change), digoxin, insulin/oral diabetes meds
• Proton pump inhibitors and certain antidepressants may alter levels

Recheck timing

• TSH (and Free T4 when indicated) about 6–8 weeks after any dose change
• Once stable, labs every 6–12 months or if symptoms change

When to re-test sooner

• New medicines that interact (iron/calcium started, PPI changes)
• New symptoms (palpitations, weight loss, insomnia) suggesting over-replacement
• Significant weight change, pregnancy planning, or acute illness

Heart disease

Start low and go slow to avoid angina or rhythm problems. Report chest pain, racing heart, or new shortness of breath.

Bone health

Too much thyroid hormone increases bone loss. Ensure dosing keeps TSH in target; keep up calcium/vitamin D if advised.

Central hypothyroidism

TSH is not reliable to monitor; dosing follows Free T4 and symptoms under specialist care.

Myxedema coma (rare emergency)

Severe hypothyroidism with confusion, low temperature, and low blood pressure. Call emergency services immediately.

Can I take levothyroxine with coffee?

Coffee can reduce absorption if taken together. Take the pill with water and wait at least 30 minutes before coffee.

Why do I still feel tired on treatment?

Other conditions (sleep apnea, anemia, depression, low activity, meds) can contribute. Check labs and look for other causes.

Is natural desiccated thyroid better?

Most guidelines prefer levothyroxine alone. Combination or desiccated products are individualized and need careful monitoring.

Do I need to avoid iodine salt?

Normal iodized salt is generally fine; avoid high-dose supplements unless prescribed.