Letrozole Side Effects: What You Need to Know Before Taking It

When you’re prescribed letrozole, a type of aromatase inhibitor used primarily to treat hormone-receptor-positive breast cancer in postmenopausal women. It works by lowering estrogen levels in the body, which can slow or stop cancer growth. Also known as an aromatase inhibitor, it’s not a chemotherapy drug but still carries real, sometimes challenging side effects that impact daily living. Many people start letrozole hoping it will keep their cancer at bay, but few are fully prepared for how it changes their body.

One of the most common issues is joint pain, a dull, persistent ache in the hands, knees, or back that can feel like early arthritis. This isn’t just discomfort—it can make walking, typing, or even getting out of bed harder. Studies show nearly half of women on letrozole report this, and it’s often worse in the first six months. Then there’s hot flashes, which aren’t just annoying; they can wreck sleep and leave you drained by midday. Fatigue is another big one. It’s not normal tiredness—it’s the kind that sticks around even after a full night’s rest. And don’t ignore bone thinning. Letrozole lowers estrogen, which protects your bones, so your doctor should check your bone density early and may recommend calcium, vitamin D, or even a bisphosphonate to keep them strong. Some people also deal with mood swings, headaches, or nausea, but these tend to fade over time. The key is tracking what happens, not ignoring it because "it’s just the medicine."

What’s often left out of the conversation is how letrozole affects relationships and self-image. Weight gain, dry skin, and hair thinning are real for many, and they hit harder than you’d expect. You might feel like you’re losing pieces of yourself—not because the cancer is winning, but because the treatment is changing your body in quiet, invisible ways. That’s why talking to others on letrozole matters. You’re not alone in feeling this way, and your doctor needs to hear the full picture—not just the clinical symptoms, but how you’re actually living with them.

Below, you’ll find real patient experiences and medical insights on managing letrozole side effects—from what helps with joint pain to how to protect your bones without adding more pills. These aren’t generic tips. They’re the kind of details you won’t find in a brochure, but they’re the ones that actually make a difference.