Cephalexin: Uses, Dosage, Side Effects and Safe Buying Tips

Cephalexin is a commonly prescribed antibiotic that treats many bacterial infections, like skin infections, strep throat, ear infections and some urinary tract infections. It belongs to the cephalosporin class and works by stopping bacteria from building cell walls, which kills them. Doctors like it because it usually works well and is easy to take.

Typical adult dosing is 250–500 mg every 6–12 hours depending on the infection. For skin infections and strep throat doctors often use 500 mg twice daily or 250 mg four times daily for 7–10 days. For urinary tract infections dosing can vary; your prescriber will pick the right length based on your symptoms and test results. Kids get doses adjusted by weight, so never use adult tablets for a child without clear guidance from a clinician.

What to expect and safety tips

Common side effects include stomach upset, nausea, and diarrhea. If diarrhea is severe, bloody, or watery, call your doctor—this might be Clostridioides difficile infection, which needs attention. Allergic reactions range from a mild rash to rare but serious anaphylaxis. If you have a penicillin allergy, tell your provider; some people allergic to penicillin also react to cephalosporins, though many tolerate cephalexin fine after assessment.

Take cephalexin with or without food; taking it with food can reduce stomach upset. Finish the full course even if you feel better early—stopping too soon can let bacteria survive and become resistant. If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose; don’t double up.

Buying cephalexin safely online

If you consider ordering cephalexin online, only use pharmacies that require a valid prescription and show clear contact details and licensing. Look for verified reviews and avoid sites that sell antibiotics without a prescription or offer unusually low prices. Check that the pharmacy lists a real address and pharmacist contact; legitimate pharmacies will also ship securely and provide patient information leaflets.

Never self-diagnose an infection. Lab tests or at least a proper exam can guide the right antibiotic choice and length of treatment. If cost is the issue, ask your prescriber about generic cephalexin or patient assistance programs—generic versions are effective and cheaper.

Keep cephalexin stored at room temperature away from moisture and light. If you have kidney disease, pregnancy, or are breastfeeding, tell your doctor—dosing or choices may change. When used correctly, cephalexin is a reliable, affordable option for many common infections. If symptoms aren’t improving within 48–72 hours, contact your healthcare provider for reassessment.

Tell your doctor about other medicines, especially blood thinners like warfarin, or drugs that affect kidneys. Probenecid can raise cephalexin levels. If you notice a new rash, swelling, trouble breathing, or severe stomach problems, stop the drug and seek help. Save the pill bottle and receipt if you need to report a bad reaction. For recurring infections, ask about culture tests to find the best antibiotic and avoid repeated, unnecessary courses. Follow your doctor's advice.