5-FU: What It Is, How It Works, and What Alternatives Exist

When you hear 5-FU, a chemotherapy drug also known as fluorouracil, used to treat cancers like colorectal, breast, and skin cancer. Also known as fluorouracil, it works by stopping cancer cells from making DNA, which keeps them from multiplying. It’s one of the oldest chemo drugs still in wide use today—not because it’s perfect, but because it’s reliable, affordable, and effective for many types of tumors.

5-FU doesn’t work alone. It’s often paired with other drugs like leucovorin to boost its effect, or used in topical creams for early skin cancers. Doctors choose it based on cancer type, stage, and patient health. But it’s not gentle. Common side effects include mouth sores, low blood counts, nausea, and hand-foot syndrome—where your palms and soles turn red and feel sore. That’s why many patients and providers look at alternatives, especially when 5-FU stops working or becomes too hard to tolerate.

Related drugs like capecitabine, an oral chemo that turns into 5-FU inside the body. Also known as Xeloda, it offers similar results without needing an IV, are often used as oral substitutes. For colorectal cancer, oxaliplatin, a platinum-based chemo often combined with 5-FU in the FOLFOX regimen. Also known as Eloxatin, it’s a key partner in many treatment plans is common. Newer options like immunotherapy or targeted therapies may replace 5-FU in some cases, especially for advanced cancers with specific genetic markers.

You’ll find posts here that compare 5-FU to other chemo drugs, explain how to manage its toughest side effects, and show what patients actually experience during treatment. Whether you’re a patient, caregiver, or just trying to understand what’s happening, the articles below give real-world insights—not just textbook facts. You’ll see how people cope with mouth sores, what blood tests matter most, and when switching drugs makes sense. No fluff. Just clear, practical info that helps you make sense of treatment choices.