Levothyroxine is a synthetic thyroid hormone doctors give when your thyroid makes too little. It replaces missing T4 so your body’s metabolism, energy, and temperature regulation stay steady. For lots of people, a single small tablet taken every morning brings back normal energy and mood.
This page focuses on practical facts: how to take levothyroxine, what interferes with it, common side effects, and when to check labs. No fluff — just the things you need to know to make the medicine work.
Take levothyroxine on an empty stomach. Most people take it first thing in the morning, 30–60 minutes before breakfast. If mornings don’t work, take it at least 3–4 hours after dinner. Stay consistent: take it the same way every day so your doctor can judge your dose reliably.
Avoid calcium, iron, multivitamins with minerals, and antacids within four hours of the dose. These bind levothyroxine and cut how much your body absorbs. Coffee can also reduce absorption if taken too soon, so wait at least 30–60 minutes after your pill to drink it.
Doctors monitor TSH (and sometimes free T4) to set the right dose. After starting or changing dose, expect blood tests every 6–8 weeks until levels stabilize. Then checks usually slow to every 6–12 months. If you’re pregnant, TSH is monitored more often because needs often rise.
Symptoms of too little thyroid replacement include fatigue, weight gain, cold intolerance, and slow thinking. Too much replacement can cause heart palpitations, anxiety, sweating, and weight loss. If you notice either pattern, call your doctor — do not change the dose yourself.
Generic levothyroxine is common and usually fine, but small differences between brands can matter for sensitive patients. If your pharmacy switches brands, watch for symptom changes and consider asking for the same brand each refill, or ask your prescriber to note “brand medically necessary” if needed.
Side effects are usually from taking too much. Rare allergic reactions can happen, but they’re uncommon. People with heart disease, older adults, or those with osteoporosis should have closer follow-up since too high a dose raises risks.
Buying levothyroxine online? Use licensed pharmacies that require a prescription. Fake or unregulated sources may sell improper doses or counterfeit pills. If price is an issue, ask your doctor about patient assistance or lower-cost generics.
Quick tips: take it consistently, separate it from calcium/iron, get labs after any dose change, and report palpitations or sudden weight change. Talk to your doctor about pregnancy, major surgery, or new medications — these can change your needs.
If you have questions about symptoms, dosing, or interactions, your healthcare team should answer them. Levothyroxine works well for most people when used correctly; the trick is consistent timing, smart monitoring, and good communication with your provider.
