Tetracycline: what it treats, side effects, and how to use it safely

Tetracycline antibiotics — like doxycycline, minocycline, and the original tetracycline — are common tools for treating acne, respiratory infections, Lyme disease, and some sexually transmitted infections. They stop bacteria from making proteins, which slows growth and lets your immune system finish the job. That makes them useful for a wide range of infections, but they also come with clear rules you should follow.

First, who shouldn’t take them: pregnant people and kids under 8 should avoid tetracyclines because these drugs can stain teeth and affect bone growth. If you’re pregnant or nursing, tell your provider before you take any antibiotic. Also mention any liver disease, since rare liver problems can happen.

How to take tetracyclines

Take them exactly as your doctor prescribes. Some quick, practical tips: swallow tablets with a full glass of water and sit upright for 30 minutes to avoid irritation. Avoid taking most tetracyclines with milk, calcium supplements, iron pills, or antacids — these bind the drug and make it less effective. Doxycycline is a bit more forgiving with food, but it still interacts with minerals, so be cautious.

Watch for photosensitivity. That’s a fancy word for getting sunburned faster. Use sunscreen and cover up when you’re outside. Common side effects are stomach upset, nausea, and yeast infections after antibiotic use. Stop the drug and call your doctor if you get severe diarrhea, rash, trouble breathing, or yellowing skin (signs of a bad reaction).

Buying tetracycline online and staying safe

If you’re considering buying tetracycline or doxycycline online, pick a licensed pharmacy that requires a prescription and shows clear contact info. Don’t chase suspiciously low prices from sites that don’t ask for a prescription — those pills may be fake or unsafe. Check expiry dates, packaging, and reviews. If something feels off, talk to a pharmacist or your provider before taking the medication.

Antibiotic resistance matters. Don’t use tetracyclines for viral infections like colds or most sore throats. Finish the full course your doctor prescribes, even if you feel better after a few days. If symptoms don’t improve after 48–72 hours for a bacterial infection, return to your provider — the bug may be resistant or you may need a different drug.

Alternatives exist depending on the infection — macrolides, penicillins, or cephalosporins might be better in some cases. Don’t switch antibiotics without medical advice. When in doubt, ask your prescriber about risks, drug interactions, and the best choice for your condition.

Got more questions about a specific tetracycline, dosing, or buying options? Reach out to a pharmacist or your healthcare provider. They can match the medicine to the problem and keep you safe while you get better.