- The dose may need adjusting.
- Coffee, calcium, iron and food can block absorption.
- Low iron, B12 or vitamin D can also cause fatigue.
- Sleep apnea, depression and other hormone problems are common hidden causes.
Many people with hypothyroidism still feel tired even when they take levothyroxine every day. This is frustrating, but there is usually a reason, and often a fix.
1. The dose is not quite right
TSH should be checked about 6 to 8 weeks after any dose change. Needs can change with weight, age, pregnancy and other medicines.
2. The pill is not being absorbed well
Levothyroxine works best on an empty stomach with water, 30 to 60 minutes before breakfast and coffee. Calcium, iron, antacids and some supplements should be taken at least four hours apart. Stomach conditions like celiac disease can also lower absorption.
3. Something else is going on
- Low iron or anemia
- Low vitamin B12 or vitamin D
- Sleep apnea or poor sleep
- Depression or anxiety
- Diabetes or prediabetes
- Low cortisol, rarely
What about T3 or desiccated thyroid?
Most people do well on levothyroxine alone. A small number may be considered for added T3 after other causes are ruled out. This decision is best made with an endocrinologist.
Learn more on our page about Hypothyroidism treatment in Chicago, or get in touch to request a visit.
Triple board-certified endocrinologist and obesity medicine specialist in Chicago. This article is for general education and is not medical advice.