Synthroid

(levothyroxine)

4.1/ 5 average rating with 1090 reviewsforSynthroid
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Replaces thyroid hormones.

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Our bottom line

Synthroid (levothyroxine) effectively replaces thyroid hormone when your body is not making enough, but it's important to take it exactly as instructed since it's affected by other medicines or supplements.

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    $4.00
Quick facts about Synthroid
  • Drug class: Endocrine
  • Rx status: Prescription only
  • Generic status: Lower-cost generic available (levothyroxine)

Upsides

  • Works well to improve symptoms of an underactive thyroid by supplying thyroid hormone.
  • Unlike some alternative supplements, Synthroid (levothyroxine) is safe to use for any age range and during pregnancy.
  • Compared to some alternative thyroid supplements, Synthroid (levothyroxine) provides a consistent amount of thyroid hormone per pill. Inconsistent amounts can be dangerous.
  • Generic versions are available.
  • Only need to take once a day.
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What to expect from Synthroid, on one page

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People’s experience with Synthroid

1090reviews so far. What do you think?

Downsides

  • Synthroid (levothyroxine) must be taken a specific way, separated from some other medicines.
  • Synthroid (levothyroxine) is only T4 thyroid hormone, which is less active than T3 hormone. It may not work for everyone.
  • Initially, your dose may be changing, until you get to the right dose that supplies the right amount of thyroid hormone.
  • Routine blood tests are needed periodically.
  • It can take 6 to 8 weeks to see the full effects.
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How it works

Synthroid (levothyroxine) is a synthetic version of the T4 thyroid hormone made by your thyroid gland. Thyroid hormones regulate metabolism, body temperature, heart rate, and other vitally important functions.

Quick facts about Synthroid
  • Drug class: Endocrine
  • Rx status: Prescription only
  • Generic status: Lower-cost generic available (levothyroxine)

Used for

Dosage forms

  • Pill
People’s experience with Synthroid

1090reviews so far. What do you think?

Prices and coupons

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What to expect when you take Synthroid (levothyroxine) for Hypothyroidism

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  • First few hoursHours
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  • Effectiveness
  • Starts to kick in
    Full effects
  • First few hoursHours
    First few daysDays
    First few weeksWeeks
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  • Possible side effects
  • Fast or irregular heartbeat
  • Excessive sweating
  • Nervousness
  • Increased appetite
  • Diarrhea
  • Difficulty sleeping
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Side effect rates for Synthroid (levothyroxine)

Risks and Warnings for Synthroid (levothyroxine)

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    • Higher risk if:
    • Taking other medicines for weight loss

    Synthroid (levothyroxine) shouldn't be used for weight loss. It’s not recommended, safe or effective for this use. Taking high doses of Synthroid (levothyroxine) can cause serious or fatal effects especially if used with other medications for weight loss. Talk to your doctor about other medicines you can take to treat your condition.

    This is a black box warning. The FDA requires this warning when there is a significant risk of serious or life-threatening effects that anyone taking the drug should consider.

Means that some groups have a high risk of experiencing this side effect

Common concerns from people taking Synthroid (levothyroxine)

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Food
  • Take Synthroid (levothyroxine) on an empty stomach with a full glass of water at least 30 minutes before breakfast and other medicines.
  • Worth it
    Big hassle
    Reviewed Synthroidon 8/8/2016Sometimes it is really hard to take it early enough before breakfast.
    44
    Woman
    Hypothyroidism
Weight
  • Synthroid (levothyroxine) shouldn't be used for weight loss. It’s not recommended, safe or effective for this use. Taking high doses of Synthroid (levothyroxine) can cause serious or fatal effects especially if used with other medications for weight loss. Talk to your doctor about other medicines you can take to treat your condition.
  • Not worth it
    Reviewed levothyroxineon 2/14/2018Gained weight instead of losing weight. Still cold all the time.
    54
    Woman
    Two years or more
    Would rather not say
  • Worth it
    Some hassle
    Reviewed Synthroidon 5/25/2015It takes time to take effect & the weight gained because of a slow thyroid did not just fall off-took me 5 years to lose.
    61
    Woman
    Two years or more