Thyroid medication: what you need to know

Feeling tired, cold, or gaining weight for no reason? Your thyroid could be the cause. Thyroid medication is simple in idea but tricky in the details. This guide explains the main medicines, how to take them, common problems, and practical tips so you can get steadier energy and better lab results.

Types of thyroid medication

Most people start with levothyroxine (synthetic T4). Brands include Synthroid and generic levothyroxine. It replaces the body’s T4 and converts into the active T3. Liothyronine (T3, brand Cytomel) acts faster and sometimes helps when symptoms persist despite normal labs. Desiccated thyroid (Armour) contains both T3 and T4 from animal thyroids. Some patients prefer it, but doses are less predictable. Doctors may use a mix of T4 and T3 for selected cases.

Which one is right? That depends on symptoms, blood tests, other health issues, and personal response. Never switch types or brands without talking to your prescriber; even small changes can shift your bloodwork.

How to take it, monitor it, and avoid problems

Take levothyroxine on an empty stomach, 30 to 60 minutes before breakfast, or at bedtime three hours after eating. Calcium, iron, antacids, and some supplements interfere with absorption. Space those by four hours. If you take many pills, try a simple routine: med box and a single time each day.

Blood tests matter. TSH is the main test. Check TSH 6 to 8 weeks after a dose change, then every few months until stable. Once stable, yearly tests often suffice. If you feel off but labs look normal, discuss free T4 and free T3 with your doctor.

Watch for signs of over-treatment: fast heart rate, shaking, trouble sleeping, or bone loss over time. Under-treated signs include fatigue, weight gain, feeling cold, and slow thinking. Elderly people and those with heart disease usually start at low doses to avoid strain on the heart.

Pregnancy changes dosing: most people need a higher dose early on. If you’re pregnant or planning pregnancy, tell your provider right away and check TSH more often. For kids, dosing is weight-based and needs closer follow-up.

Buying and handling meds: get thyroid meds from licensed pharmacies only. Generic levothyroxine is fine for most, but switching brands may need another TSH check. Store tablets away from moisture and heat. If you have trouble swallowing, liquid or gel caps exist.

If symptoms persist despite normal labs, ask about adrenal issues, vitamin D, iron, and sleep problems. Thyroid meds help many people, but they work best when the whole picture is checked. Keep notes on symptoms, doses, and lab dates so your clinician can fine-tune treatment.

Missed a dose? Take it as soon as you remember the same day. Don't double up the next day. If you take other meds every morning, try moving thyroid pill to night. Keep a copy of your current dose and lab results when you see new doctors or travel. That saves time and prevents mistakes. Ask questions until you understand.