Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Levothyroxine.

Bone density: Levothyroxine can cause bones to lose thickness. If you have an increased risk for Osteoporosis (bone thinning) or are taking medications that reduce bone thickness (e.g., Prednisone or antiseizure medications), before you start taking Levothyroxine, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

Your doctor may monitor your bone thickness while you are taking Levothyroxine.

Diabetes: Levothyroxine raises blood sugar levels. For people with diabetes, this may result in an increase in the requirements for insulin or antidiabetes medications. If you have diabetes or are at an increased risk of developing diabetes, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

You may need to monitor your blood sugar more closely when starting Levothyroxine or changing doses of Levothyroxine.

Heart disease: When starting levothyroxine, people with heart disease may be started on a lower dosage as it may cause the heart to work harder than it has been used to. If you have heart disease, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

Signs of getting too much or too little medication: Contact your doctor as soon as possible if you notice any signs of getting too much medication (such as chest pain, confusion, fast or irregular heartbeat, mood swings, muscle weakness, psychosis, extreme restlessness, yellow eyes or skin, or shortness of breath) or signs of not getting enough medication (such as clumsiness, coldness, Constipation, dry, puffy skin, listlessness, muscle aches, sleepiness, tiredness, weakness, or weight gain).

Weight loss: Levothyroxine should not be used for weight loss. Large doses of levothyroxine can cause serious ore even life threatening side effects especially when taken together with other medications for weight loss.

Pregnancy: Levothyroxine should be taken throughout pregnancy to regulate the levels of thyroid hormone for the pregnant mother and the developing baby. If you become pregnant while taking Levothyroxine, contact your doctor as soon as possible. Your doctor may want to monitor your thyroid function more closely while you are pregnant.

Breast-feeding: Only a small amount of thyroid hormone is passed into breast milk. The use of appropriate amounts of Levothyroxine by breast-feeding women has not been shown to cause harm for breast-fed babies.

Seniors: Seniors may be more sensitive to the effects of levothyroxine.