Original Drugs, Generics, and Biosimilars: What’s the Difference

When a doctor prescribes medication, a pharmacy often offers several options — an original drug, its generic, or a biosimilar. The price difference can be significant, which raises many questions: What do these terms mean? Are generics safe? Can biosimilars be trusted?

Let’s explain these terms in simple language. Understanding the difference helps patients make informed choices without compromising treatment quality.

What Are Original Drugs?

These are the first medicines developed by a pharmaceutical company after years of research and billions in investment. They undergo full clinical trials and obtain a patent proving safety and efficacy. Because of high development costs, original drugs are usually more expensive.

What Are Generics?

After a patent expires, other manufacturers can produce equivalents known as generics. They contain the same active ingredient, dosage, and form as the original medicine.

Main Features of Generics:

• Identical composition: A generic is essentially a “copy” of the original drug, using the same active molecule.
• Proven bioequivalence: To be approved, a generic must demonstrate that it works in the body the same way as the original.
• Lower price: Since generics don’t require new research, they are significantly more affordable.

For example, a nephrology medicine with the same active ingredient “Y” can be sold by different brands — but all versions act the same way.

What Are Biosimilars?

With the development of biotechnology, new types of medicines have appeared — biological drugs. They are produced not by chemical synthesis but using living cells — for example, monoclonal antibodies used in chemotherapy for solid tumors.

A biosimilar is an analogue of such a biological medicine. Unlike chemical generics, biosimilars cannot be exact copies due to the complexity of living systems involved in production.

Main Features of Biosimilars:

• Highly similar but not identical: A biosimilar closely matches the original in structure and effect, with minor differences that don’t impact safety.
• Extensive clinical testing: Biosimilars undergo more rigorous studies than generics to prove both bioequivalence and clinical similarity.
• Safety and efficacy: Once approved by regulators, biosimilars are considered as safe and effective as their originals.

Biosimilars are now widely used in hematology and for the treatment of multiple sclerosis, making advanced therapies more accessible to patients.

Key Differences in Table Form

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult your doctor or pharmacist before taking any medication.