Tresiba 100 Units/ml Penfill (3ml Each) is an ultra long-acting type of insulin used to treat types 1 and 2 diabetes mellitus in both adults and children. It provides a steady level of insulin in the body for an entire day and helps control blood sugar levels. This helps to prevent complications of diabetes. Tresiba 100 Units/ml Penfill (3ml Each) can be prescribed by itself or along with a fast-acting type of insulin or other diabetes medicines. Your doctor or nurse will teach you the correct way of injecting it under the skin. You should use this medicine regularly as per the dose advised to get the most benefit. It is usually taken once daily at the same time every day. However, on occasions when administration at the same time of the day is not possible, it may be taken at a different time of the day. Always ensure that there is a minimum gap of 8 hours between doses. If you stop taking it your blood sugar levels may rise very high and put you at risk of serious complications. It is only a part of the treatment program that should also include a healthy diet, regular exercise, and weight reduction as advised by your doctor.The most common side effects of this medicine is low blood sugar levels (hypoglycemia). To prevent hypoglycemia, it is important to always inject only the correct dose of medicine, have regular meals, and monitor your blood sugar levels regularly. Drinking excessive alcohol can also lead to a fall in your blood sugar levels. Other side effects include injection site reactions like redness, swelling, or hard lumps (lipohypertrophy). Some people may also gain weight while taking insulin.Do not use this medicine when you have low blood sugar levels (hypoglycemia). Tell your doctor if you have ever had kidney, liver, or heart problems before starting treatment. Pregnant or breastfeeding women should also consult their doctor before using it.