{"id":628828,"date":"2024-07-03T11:27:40","date_gmt":"2024-07-03T15:27:40","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=628828"},"modified":"2025-12-18T09:18:47","modified_gmt":"2025-12-18T14:18:47","slug":"how-long-does-it-take-for-levothyroxine-to-work","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/how-long-does-it-take-for-levothyroxine-to-work\/","title":{"rendered":"How long does it take levothyroxine to work?"},"content":{"rendered":"

Levothyroxine, also known by brand names like Synthroid, Tirosint, and Levoxyl, is a thyroid medicine known as thyroid replacement therapy or thyroid hormone replacement. It is used in people with an underactive thyroid (hypothyroidism) and replaces the thyroid hormone the body normally makes. It is also used to treat certain types of thyroid cancer and thyroid disorders. Many people who start taking levothyroxine for hypothyroidism want to know how fast it will start working. The good news is that levothyroxine starts to work immediately for thyroid disease, but it may take up to four to six weeks to notice the medication’s full benefit. Continue reading to learn more about levothyroxine.<\/span><\/p>\n

RELATED: <\/b>What is levothyroxine?<\/b><\/a> | <\/b>Levothyroxine coupons<\/b><\/a><\/p>\n

How long does it take for levothyroxine to work?\u00a0<\/span><\/h2>\n

When your healthcare provider prescribes levothyroxine, they will determine the starting dose depending on several factors, such as your age, weight, lab values, and other medications you take.\u00a0<\/span><\/p>\n

Levothyroxine starts to work immediately; however, it may take up to <\/span>four to six weeks<\/span><\/a> to see its full effect. Even if you do not notice a difference in symptoms immediately, the medication takes time to start regulating your thyroid levels. It\u2019s important to continue to take your daily dose as directed.<\/span><\/p>\n

A dose adjustment may be required in some cases. Your healthcare provider will order blood work, generally about <\/span>six weeks<\/span><\/a> after you start taking levothyroxine, to see how well the medication is working. The blood tests will check your <\/span>thyroid-stimulating hormone (TSH)<\/span><\/a> levels to measure your thyroid function.<\/span><\/p>\n

Once the medication reaches a steady level in the body, in about six weeks, your hypothyroidism symptoms should subside as your thyroid hormone levels regulate.\u00a0<\/span><\/p>\n

If, after several weeks, your symptoms worsen or do not improve, your healthcare provider may need to adjust the dose of your medicine. Generally, healthcare providers will <\/span>check TSH levels and adjust doses<\/span><\/a> every six to eight weeks, if required, until thyroid levels normalize. Older adults or people with heart problems may be monitored more frequently, like every four to six weeks, until levels normalize. Once your healthcare provider determines that you are taking the right dose and your TSH level is appropriate, they may check again in three to six months, then every six to 12 months.\u00a0<\/span><\/p>\n

How do you know levothyroxine is working?<\/span><\/h2>\n

Some <\/span>common symptoms<\/span><\/a> of hypothyroidism include:<\/span><\/p>\n