What is Fiasp Insulin?

Fiasp is the brand name of the drug insulin aspart. Insulin is a hormone that is typically produced naturally in the pancreas. It is responsible for regulating levels of sugar in the blood. People with diabetes require extra insulin because their bodies either cannot produce it or cannot use the naturally produced insulin properly.

What is this medication used for?

Fiasp is used to improve blood glucose control in children and adults with diabetes. It should not be used in children under the age of 2 and should not be used to treat type 2 diabetes in children. Fiasp is fast-acting and can sometimes be used in combination with immediate-acting or long-acting insulin products.

How to take it

Fiasp insulin should be taken according to the patient’s prescription label and guidance from their pharmacist and/or doctor. It can be injected under the skin or as an infusion directly into a vein. The first dose will likely be given by a healthcare provider to show the patient how to use the medication properly.

Fiasp is fast-acting, which means it begins working approximately 15 minutes after injection. The effectiveness peaks approximately one hour after injection, and it continues to work for up to 4 hours.

Patients should take Fiasp with a meal or within 20 minutes of eating. If taking Fiasp with an injection pen, patients should only use the pen provided with the prescription. If taken with an insulin pump, this insulin should not be mixed or diluted with any other insulin medications.

Fiasp side effects

Fiasp insulin is safe and effective and was approved by the Food and Drug Administration (FDA) in June 2000. A new and improved formula was approved in 2017. Despite its proven safety, patients may experience some adverse effects. If A patient experiences severe side effects as a result of Fiasp use, they should contact their doctor immediately.

Common side effects

  • Low blood sugar
  • Weight gain
  • Mild skin rash or itching
  • Hollowing or thickening of the skin at injection site

Severe side effects

• Heart problems that could be indicated by shortness of breath, sudden weight gain, or swelling
• Low potassium as indicated by constipation, leg cramps, irregular heartbeats, increased thirst or urination, muscle weakness, or numbness


Dosage depends on the patient’s blood glucose monitoring results, metabolic needs, and glycemic control goals. The dosage strength of Fiasp is 100 units/mL. The maximum dose per injection is 80 units, and the Fiasp pen releases the injections in 1-unit increments.


Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.