What Are Biosimilars and Are They Safe to Use?

A biosimilar is a drug similar to a Food and Drug Administration (FDA)-approved biologic drug in structure and function. Biologic drugs and biosimilars are complex molecules produced in a living system (microbes or cells from humans, plants, or animals). They are both made using advanced biotechnology.

Biosimilars have been created to help expand access to costly and/or life-saving medications and provide more treatment options. For FDA approval, a biosimilar must be proved as safe and effective as the reference biologic drug, and the two may be used interchangeably with "no clinically meaningful differences."

Researcher holding a model of a chemical molecule

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Biosimilars first came into use in the United States in 2015 but had been in use in Europe for several years prior. As such, there is data on their efficacy and safety in the real world.

Some examples of biosimilar drugs include Herzuma (trastuzumab-pkrb), a targeted cancer drug for breast cancer that is a biosimilar to Herceptin (trastuzumab), and Amjevita (adalimumab-atto) for the treatment of rheumatoid arthritis, which a biosimilar to Humira (adalimumab).

This article will describe how biosimilars differ from biologics and generic drugs, their benefits, and their naming conventions.

How Are Biosimilars Different From Biologics?

Biologic drugs and biosimilars are produced from one of the following natural mediums:

  • Yeast
  • Microorganism
  • Human cell
  • Plant cell
  • Animal cell

A biosimilar is developed to produce the same effect as its reference biologic drug but is not identical in chemical structure.

Biologics are often more expensive than biosimilars. This makes biosimilars a more attractive choice.

How Are Biosimilars Different From Generics?

Generic drugs are the exact same chemical molecule as a brand-name reference drug. These drugs are typically smaller molecules that chemical processes produce.

Biologics are large and complex molecules. Due to the complexity of a biologic drug, a batch of a biologic drug such as Humira is not exactly identical to another batch of Humira but still produces the same effects.

Unlike generic drugs, the active ingredient in a biosimilar drug is not chemically identical to its biologic reference drug. Biosimilars must undergo more rigorous testing than generic drugs to show they produce the same effects as the reference drug.

Some biosimilars are interchangeable products. This means they have met additional requirements for evaluation and testing, and the FDA approves them to be substituted for a biologic drug without the need for a change in a prescription. You can request the substitution from a pharmacist.

Benefits of Biosimilars

The benefits of biosimilars include cost and increased competition.

Cheaper Than Biologics

Not only are biosimilars as effective as biologics, but they are almost always more affordable. On average, biosimilars are 30% cheaper than biologic reference drugs. These savings could amount to hundreds or even thousands of dollars depending on the volume and frequency of your medication use.

If you are prescribed a biosimilar, your out-of-pocket cost for coinsurance (a percentage of the cost of a prescription or service) may also be reduced compared to the biologic drug it replaces.

The cost savings are mainly the result of a shortened approval process compared with the biologic reference drug. Though longer than the process to approve a generic drug, it involves fewer clinical trials than for a biologic reference drug. The approval process still ensures safety and effectiveness standards.

One pharma industry report found that drug cost savings due to the greater availability and use of biosimilars are estimated to be about $100 billion from 2020–2024.

Even more, the potential savings from biosimilars in light of inefficient pharma spending (despite making up only 2% of all drug prescriptions, biologics make up nearly half of all U.S. drug spending) plus widening wealth gaps underscore the continued need to provide cheaper drug alternatives.

Competition Keeps Other Prices Low

Studies have shown that competition in the drug market results in lower prices, but questions about how low prices must go to truly benefit healthcare consumers have arisen.

Competition forces drugmakers to negotiate lower prices to capture the market. Though this theory has been proved in some instances, it has not materialized in others. High drug prices have become such a problem that Congress has revisited the issue several times.

In 2017, the FDA’s Drug Competition Committee issued a statement about how to increase access to more affordable medications. Their suggestions included improving the efficiency of the drug approval process, increasing drug pricing transparency, and closing loopholes that allow brand-name drug companies to derail competition from generics and biosimilars.

How Are Biosimilars Named?

If you see the name of a common drug followed by a dash and four random letters, chances are it’s a biosimilar. The standard biosimilar nomenclature is to combine the core name of a drug with a unique suffix (those random four lowercase letters).

These letters mean nothing and are simply placed there to distinguish between a biologic and a biosimilar. For example, the biosimilar name for Remicade (infliximab), an immunosuppressant drug for treating rheumatological conditions, is Avsola (infliximab-axxq).


Biologics are drugs with active ingredients that are complex molecules produced by or from living organisms or cells. Due to the complex process of developing biosimilars, they are not exactly the same chemically as one another, nor are biosimilars the same as the reference biologic drug they replace.

Biosimilars are approved by the FDA after a process that shows they have the same effectiveness as the biologic reference drug. Biosimilars are often more accessible, as effective, and cheaper than biologics, making them a viable option for many people.

A Word From Verywell

If you want a safe and effective alternative to a biologic drug, ask your healthcare provider whether a biosimilar is available. This may reduce the cost of your treatment.

Frequently Asked Questions

  • Are biosimilars safe?

    Biosimilars are tested for safety prior to their release into the market. They must be as safe and efficient as their biologic reference drugs to be approved by FDA.

  • Are biosimilars cheaper?

    Biosimilars tend to be cheaper than biologics because they undergo a less costly, more efficient approval process. 

  • Are biosimilars as effective as biologics?

    Biosimilars are highly similar to biologics. To gain FDA approval, they must prove there is no clinically meaningful difference in safety or effectiveness.

  • Are biosimilars approved by the FDA?

    Biosimilars are approved by the FDA and must meet rigorous approval standards.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food And Drug Administration. About biosimilars and interchangeable products.

  2. IQVIA. Biosimilars in the United States, 2020-2024.

  3. American Cancer Society. What are biosimilar drugs?

  4. Department of Health and Human Services. American Patients First: The Trump Administration Blueprint to Lower Drug Prices and Reduce Out-of-Pocket Costs. May 2018.

  5. AJMC The Center for Biosimilars. Alphabet soup: the story behind biosimilar nonproprietary name suffixes.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.