Evergreening in Pharma: How Drug Companies Extend Patents and Impact Medication Costs

When a drug’s original patent runs out, evergreening is the practice some companies use to keep it protected anyway. This isn’t about inventing something new—it’s about making small changes to an existing drug, like tweaking the dosage form, combining it with another ingredient, or changing how it’s delivered. These tweaks aren’t always medically meaningful, but they’re enough to trigger new patents and block generics from entering the market. The evergreening, a strategy used by pharmaceutical companies to extend market exclusivity through minor product modifications. Also known as patent evergreening, it directly influences how long patients pay high prices for brand-name drugs. This isn’t just a legal trick—it’s a financial one, and it hits hard when people need affordable medicine.

Evergreening ties directly into how biosimilars, lower-cost versions of complex biologic drugs that can only enter after 12 years of exclusivity under U.S. law struggle to reach patients. Even after the main patent expires, companies pile on secondary patents—covering delivery devices, manufacturing methods, or even patient support programs—to create what’s called a "patent thicket." It’s like a legal maze. The generic drugs, affordable alternatives to brand-name medications that must prove bioequivalence to gain FDA approval can’t jump in until every single patent is cleared, even if the original innovation is decades old. That’s why you see biosimilars like those for Humira or Enbrel still waiting years after the core patent expired. Meanwhile, patients keep paying hundreds or thousands of dollars per month for drugs that could cost a fraction of that.

It’s not just about money—it’s about access. When evergreening delays generics, it affects people with chronic conditions like rheumatoid arthritis, diabetes, or asthma who rely on steady medication. Doctors want to prescribe cheaper options, but insurance and pharmacy systems often lock them into the branded version because of patent restrictions. The pharmaceutical patents, legal protections that grant exclusive rights to manufacture and sell a drug for a set period, typically 20 years from filing system was meant to reward innovation, not to lock in profits long after the science is outdated. And yet, that’s exactly what’s happening. Some of the posts in this collection show how this plays out: from the slow rollout of biosimilars due to legal barriers, to how patient-reported outcomes reveal the real-world cost burden, to how cultural attitudes shape whether people even trust generic alternatives.

What you’ll find here isn’t just theory—it’s real cases. You’ll see how hydroxychloroquine’s use changed not just because of science, but because of patent timing and public perception. You’ll read about how bioequivalence testing proves generics work the same, yet still get blocked by legal loopholes. You’ll learn how healthcare providers try to advocate for cheaper options, only to run into systems designed to protect branded drugs. This isn’t about one drug or one company. It’s about a system that keeps prices high, even when the science says it doesn’t need to. And if you’ve ever wondered why your prescription costs so much, the answer often starts with evergreening.