Feb, 28 2026
Have you ever heard your doctor mention a biosimilar and wondered what it really means? You're not alone. Many patients are confused when they hear this term, especially if they’re used to generic pills like ibuprofen or metformin. But biosimilars aren’t generics. They’re something different-and here’s the good news: they’re just as safe and effective as the original biologic drugs you may already be taking.
What exactly is a biosimilar?
A biosimilar is a type of medicine that is made to be almost identical to a biologic drug that’s already been approved by the FDA. Think of it like this: if a biologic is a handmade sweater woven with complex threads, a biosimilar is another handmade sweater made using the same pattern, same yarn, and same knitting technique. It’s not a copy-paste version-it’s built to perform the same way, with no meaningful differences in how it works or how safe it is.
Biologic drugs aren’t made in a lab like aspirin. They come from living cells-usually yeast, bacteria, or animal cells-that have been genetically engineered to produce proteins. These proteins can be antibodies, hormones, or enzymes. For example, drugs like Humira (adalimumab) or Enbrel (etanercept) are biologics used for arthritis. Their biosimilars, like Amjevita or Etanercept-szzs, are designed to do the exact same thing: reduce inflammation, manage pain, and improve quality of life.
How is a biosimilar different from a generic drug?
This is where most people get confused. A generic drug is a chemical copy of a small-molecule medicine. For instance, the generic version of Lipitor is atorvastatin. It’s the same molecule, same atoms, same structure. You can make it in a factory using chemicals, and every batch is nearly identical.
But biologics? They’re huge, complex molecules. Think of them like a 3D puzzle with thousands of moving parts. Even tiny changes in how they’re made-like the temperature during production or the type of cell used-can affect how they behave in your body. That’s why you can’t just copy a biologic like you copy a pill. A biosimilar must be shown through hundreds of tests to be highly similar to the original. The FDA requires data from analytical studies, animal tests, and sometimes clinical trials involving hundreds of patients before approving one.
Bottom line: generics = exact chemical copies. Biosimilars = highly similar biological copies.
Are biosimilars safe?
Yes. The FDA doesn’t approve a biosimilar unless it proves it works just as well and is just as safe as the original. The agency compares the biosimilar to the reference product in every way: molecular structure, how it binds to targets in your body, how long it lasts in your bloodstream, and even how your immune system reacts to it.
Since 2015, when the first U.S. biosimilar (Zarxio for chemotherapy patients) hit the market, over 40 have been approved. Thirty-two are currently available. In Europe, where biosimilars have been used for over a decade, studies show no increase in side effects or loss of effectiveness compared to the original drugs.
One of the most studied biosimilars is Renflexis (infliximab-abda), used for rheumatoid arthritis. It was tested in a clinical trial with 541 patients-and its results matched those of the original drug, Remicade, exactly.
Why do biosimilars matter to patients?
Biologic drugs are expensive. A single dose of Humira can cost over $7,000. That’s why many patients struggle to afford them, even with insurance. Biosimilars are typically priced 15% to 30% lower than their reference products. That doesn’t mean they’re cheaper because they’re weaker-it means they’re more affordable because manufacturers don’t have to pay for the original research and development.
Some insurance plans now require patients to try a biosimilar before covering the brand-name biologic. This isn’t about cutting corners-it’s about making sure more people can get the treatment they need without financial hardship.
And here’s another important point: switching from a brand-name biologic to a biosimilar is safe. Multiple studies, including ones from the Arthritis Foundation and the American Cancer Society, show no difference in outcomes when patients switch. You won’t lose effectiveness. You won’t suddenly develop new side effects. Your body responds the same way.
How do you know if you’re getting a biosimilar?
Biosimilars have different names than the original drugs. The FDA requires a four-letter suffix to tell them apart. For example:
- Original: adalimumab (Humira)
- Biosimilar: adalimumab-atto (Amjevita)
- Original: infliximab (Remicade)
- Biosimilar: infliximab-dyyb (Renflexis)
These suffixes help doctors and pharmacists track which version you’re taking, especially if you have side effects. The FDA monitors every biosimilar after it’s approved, so if something unusual happens, they’ll know exactly which product was involved.
What about interchangeable biosimilars?
There’s a special category called “interchangeable” biosimilars. These are biosimilars that the FDA says can be swapped for the original drug without even asking your doctor. The first one approved in the U.S. was Semglee (insulin glargine-yfgn), a biosimilar to Lantus. It’s used for diabetes and can be substituted at the pharmacy just like a generic.
More interchangeable biosimilars are expected in the next few years, especially for common conditions like rheumatoid arthritis and Crohn’s disease. This could make switching even easier and more common.
What should you do if your doctor suggests a biosimilar?
Ask questions. It’s okay to be curious. You might ask:
- Is this biosimilar approved for my exact condition?
- Has it been tested in people like me?
- Will my insurance cover it, or will I pay less?
- Can I switch from my current drug safely?
Your doctor or pharmacist can explain why a biosimilar might be a good fit. Many patients find they feel the same-or even better-after switching, because they can finally afford their treatment.
What’s next for biosimilars?
The market is growing fast. In the U.S., biosimilars make up about 10% of the biologic drug market. In Europe, it’s 25%. By 2028, experts predict the global biosimilars market will be worth over $30 billion. More drugs are coming: biosimilars for cancer treatments like Herceptin and Avastin, insulin for diabetes, and even eye treatments for macular degeneration.
The goal? More access. Lower costs. Better care. And for patients, that means fewer people have to choose between paying rent and taking their medicine.
Are biosimilars experimental?
No. Biosimilars are not experimental. They go through the same strict testing as original biologics. The FDA requires extensive data on structure, function, safety, and effectiveness before approval. Many have been used safely in Europe for over 10 years.
Can I switch from my biologic to a biosimilar?
Yes. Studies show that switching from a brand-name biologic to an approved biosimilar is safe and doesn’t reduce effectiveness. The Arthritis Foundation and American Cancer Society both confirm this. Always talk to your doctor before making any changes.
Do biosimilars have the same side effects as the original?
Yes. Because they work the same way in your body, biosimilars have the same potential side effects as the original biologic. This includes things like injection site reactions, fatigue, or increased risk of infection. Your doctor will monitor you just as they would with the original drug.
Why are biosimilars cheaper if they’re so complex to make?
While manufacturing biosimilars is expensive, companies don’t have to repeat the original research and clinical trials. They build on the existing data of the approved biologic. This cuts costs significantly, which translates to lower prices for patients and insurers.
Will my insurance force me to use a biosimilar?
Some insurance plans require patients to try a biosimilar first before covering the more expensive brand-name drug. This is called a step therapy policy. It’s not meant to deny care-it’s meant to help control costs so more people can afford treatment. You can always appeal if you feel the original drug is better for you.
If you’re taking a biologic for a chronic condition like arthritis, Crohn’s, or diabetes, a biosimilar could be a smart, safe, and more affordable option. You’re not giving up quality-you’re gaining access.