Hypothyroidism treatment: what works, what to expect

Feeling tired, cold, or gaining weight for no clear reason? Those are common signs of an underactive thyroid. Treating hypothyroidism is usually straightforward, but the details matter—correct diagnosis, the right medicine and regular monitoring make a big difference in how you feel.

How hypothyroidism is diagnosed

Your doctor will check blood tests. The most useful are TSH and free T4. High TSH with low or low-normal free T4 usually means primary hypothyroidism. Doctors may also look for anti-thyroid antibodies (anti-TPO) to see if autoimmune thyroiditis is the cause. Don’t skip lab follow-ups—TSH is the main guide for treatment adjustments.

Key medicines and how to take them

Levothyroxine (synthetic T4) is the standard treatment. It replaces the missing thyroid hormone and is effective for most people. Typical practice is to start a dose based on age, weight, and heart health—older adults or those with heart disease often start lower. Your provider will adjust the dose based on TSH.

Take levothyroxine on an empty stomach, usually 30–60 minutes before breakfast or at least 3–4 hours after your last meal. That helps the body absorb it better. Avoid taking it at the same time as calcium, iron, aluminium-containing antacids, or certain supplements—these reduce absorption. If you must take them, separate by at least four hours.

Some people use natural desiccated thyroid (NDT) or combination T4/T3 therapy. These options exist but aren’t first choice for most doctors. If you switch products or brands, get TSH checked 6–8 weeks later because absorption and potency can vary.

After starting or changing a dose, expect a TSH test about 6–8 weeks later. Once stable, many people test every 6–12 months or when symptoms change. Signs of too little hormone: fatigue, weight gain, cold sensitivity. Too much: nervousness, palpitations, weight loss, trouble sleeping, or bone thinning over time.

Special situations: in pregnancy thyroid needs usually rise—pregnant people need closer monitoring and dose increases. Older adults and those with heart disease need gentler dosing. Children require weight-based dosing and close follow-up.

Practical tips: set your pill next to your toothbrush to build a routine, use a pill organizer if you take other meds, and tell all your providers you take thyroid medicine so they can avoid interactions. If you start feeling worse after a dose change, call your doctor instead of waiting months.

If you have severe symptoms—chest pain, fainting, sudden breathlessness—or if you’re planning pregnancy, get medical advice quickly. Proper hypothyroidism treatment helps energy, mood, weight and overall health. With the right dose and follow-up, most people feel much better within weeks to months.