Levothyroxine

About

About levothyroxine Key facts Who can and cannot take levothyroxine How and when to take levothyroxine Side effects Pregnancy and breastfeeding Cautions with other medicines Common questions about levothyroxine Levothyroxine is a medicine used to treat an underactive thyroid gland (hypothyroidism). The thyroid gland makes thyroid hormones which help to control energy levels and growth. Levothyroxine is taken to replace the missing thyroid hormone thyroxine. Levothyroxine is only available on prescription. It comes as tablets or as a liquid that you swallow. Levothyroxine is a synthetic version of a hormone called thyroxine. It replaces thyroxine if your thyroid gland cannot produce it and prevents the symptoms of hypothyroidism. Levothyroxine starts working straight away, but it may be several weeks before your symptoms start to improve. The most common side effects of levothyroxine are caused by taking a bigger dose than you need. Your doctor can lower your dose to help reduce any side effects. Before you start taking levothyroxine, your doctor will do a blood test. Once you start taking the medicine you'll have regular blood tests to see how well it's working. Levothyroxine doses need to be carefully monitored during pregnancy. If you're planning to become pregnant or think you may be pregnant, it's important to talk to your doctor to get the right care for you and your baby. Levothyroxine can be taken by most adults and children. However, it’s not suitable for some people. Check with your doctor before taking levothyroxine if you: have ever had an allergic reaction to levothyroxine or any other medicine you have an overactive thyroid that produces too much thyroid hormone (thyrotoxicosis) have a health problem that affects your adrenal glands (your doctor will be able to tell you if you're not sure) have a heart problem including angina, heart disease or heart failure have high blood pressure have ever had a heart attack have diabetes – the dose of your diabetes