Feeling sluggish, cold, or gaining weight for no obvious reason? Levothyroxine is the most common medicine for hypothyroidism — it replaces the missing thyroid hormone and helps you get energy, clear thinking, and normal metabolism back. This page gives straightforward, practical tips so you know how to take it safely and what to watch for.
Take levothyroxine on an empty stomach, usually 30–60 minutes before breakfast. If mornings don’t work, you can take it at bedtime at least 3 hours after your last meal. Stick to the same routine every day — consistency matters because food and some supplements change how much of the drug your body absorbs.
Swallow the tablet with a full glass of water. If you use liquid or gel-capsules, follow the product instructions. Never chew or crush extended-release forms unless your pharmacist tells you it’s safe.
Typical adult maintenance doses run from about 75–125 mcg daily, but many people use anywhere from 25 to 200 mcg depending on age, weight, and how badly the thyroid is underactive. Doctors often start elderly patients or anyone with heart disease at a low dose (12.5–25 mcg) and raise it slowly.
Your thyroid-stimulating hormone (TSH) is the main lab test to check if the dose is right. Expect a blood check 6–8 weeks after any dose change, then once or twice a year when stable. Pregnant people usually need a higher dose — often about a 20–30% increase — and need closer monitoring.
Watch for common interactions: calcium, iron, magnesium, antacids, soy products, high-fiber meals, and some cholesterol binders reduce levothyroxine absorption. Take those supplements or calcium-rich foods at least 4 hours apart. Medications like estrogen, some antidepressants, and certain anticonvulsants can change how much levothyroxine you need. Levothyroxine can increase the effect of warfarin, so your INR may need closer checks.
Side effects usually mean the dose is too high: racing heart, anxiety, tremors, sweating, or unplanned weight loss. If you get chest pain, palpitations, or sudden shortness of breath, seek medical care right away. Don’t use levothyroxine to lose weight — it’s unsafe and often backfires.
Storage is simple: keep pills in their original container at room temperature, away from moisture and heat. Keep track of refills and never change brands or strengths without telling your prescriber, because some products absorb differently.
Got questions about alternatives? We have an article on Armour Thyroid if you’re curious about natural desiccated thyroid and how it compares. Always talk to your doctor before switching or changing dose — they’ll look at symptoms, labs, heart health, and pregnancy plans to pick the safest option for you.
Want a quick checklist? Take levothyroxine on an empty stomach, separate it from calcium/iron, check TSH 6–8 weeks after changes, start low if you have heart disease, and call your provider for any worrying symptoms. That keeps treatment safe and effective.
