This site is intended for U.S. health care professionals.
This site is intended for U.S. health care professionals.

Biosimilars PDF Resource Summary

What is a Biosimilar?

Helpful information from the FDA explaining what a biosimilar is.

A biosimilar is a biological product

FDA-approved biosimilars have been compared to an FDA-approved biologic, known as the reference product. Reference and biosimilar products are:

Large and generally complex molecules

Produced from living organisms

Carefully monitored to ensure consistent quality

A biosimilar is highly similar to a reference product

For approval, the structure and function of an approved biosimilar were compared to a reference product, looking at key characteristics such as:


Molecular Structure


The data from these comparisons must show that the biosimilar is highly similar to the reference product.

A biosimilar has no clinically meaningful differences from a reference product

Studies were performed to show that biosimilars have no clinically meaningful differences in safety, purity, or potency (effectiveness) compared to the reference product:

Pharmacokinetic and, if needed, pharmacodynamic studies

Immunogenicity studies

Additional clinical studies as needed

A biosimilar is approved by FDA after rigorous evaluation and testing by the applicant

Prescribers and patients can feel confident about using these medications instead of reference products because biosimilars:

Meet FDA’s rigorous standards for approval

Are manufactured in FDA-licensed facilities

Are tracked as part of post-market surveillance to ensure continued safety

Additional Biosimilars Resources


FDA requires biosimilar and interchangeable biological products meet the Agency’s rigorous approval standards.


Biosimilars Forum

Providing evidence-based information to inform and support public policies that encourage awareness, access, and adoption of biosimilars.


FDA, Food and Drug Administration.