How to Take Synthroid for Weight Loss

Co-authored by Erik Kramer, DO, MPH

Updated: April 11, 2020

You may have heard that Synthroid (levothyroxine) can cause weight loss. While this is partly true, taking Synthroid to manage hypothyroidism can help reverse the weight gain associated with that condition. To get a prescription for Synthroid, get a hypothyroidism diagnosis from your doctor and take the tablet or liquid medication once a day. If you're also trying to lose weight, it's important to eat a healthy diet and exercise regularly.

Method 1 of 3:
Getting a Prescription and Starting Synthroid

  1. 1
    Get a hypothyroidism diagnosis from your doctor. If you suspect your weight gain is caused by an underactive thyroid, schedule a doctor's appointment. Pay attention to other signs of hypothyroidism, such as fatigue, sensitivity to cold, dry skin, constipation, facial puffiness, muscle pain, and menstrual irregularities in women.The doctor will perform a physical exam and send for bloodwork to diagnose hypothyroidism.[1]
    • Synthroid is not prescribed solely for weight loss, but your doctor can prescribe it to manage hypothyroidism.
  2. 2
    Tell your doctor if you have untreated adrenal problems or heart disease. Synthroid can make these health conditions worse, so your doctor shouldn't prescribe it. In addition to giving the doctor your full medical history, it's important to tell them if you have untreated adrenal or pituitary gland problems or have a history of heart disease. You should also tell your doctor if you have blood clotting problems or diabetes, since you may need to adjust medications to treat those conditions while you take Synthroid.[2]
    • You should also remind your doctor if you're taking other prescription medications.
  3. 3
    Talk to your doctor about taking prescription Synthroid. If your doctor wants to treat your hypothyroidism with Synthroid or the generic Levothyroxine, they'll write you a prescription for an oral solution, tablet, or caplet. You'll need to take the medication once a day.
    • Keep in mind that your doctor may want to adjust your dosage of Synthroid after you've been on the medication for a few weeks.
    • If you want Synthroid instead of the generic version, make sure you request it specifically.
  4. 4
    Pay attention to muscle weakness and other common side effects. Some people taking Synthroid notice muscle weakness, headache, leg cramps, nervousness, difficulty sleeping, or diarrhea. When you meet with your doctor for a follow-up appointment, tell them if you're experiencing any of these side effects.[3]
    • Your doctor may want to adjust your dose of Synthroid to manage the side effects.
  5. 5
    Contact your doctor if you have chest pain or other rare side effects. Talk with your doctor if you notice a change in your heartbeat, chest pain, or have trouble catching your breath. You should also tell your doctor if you experience:[4]
    • Change in appetite
    • Vomiting
    • Changes to your menstrual cycle
    • Sensitivity to heat or fever

    Tip: Get emergency medical attention if you think you're having an allergic reaction to Synthroid. Signs of an allergic reaction include: hives, difficulty breathing, facial swelling or swelling of your lips, tongue, or throat.

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Method 2 of 3:
Taking Synthroid Effectively

  1. 1
    Drink a Synthroid solution or dilute it in water first. If your doctor prescribed an oral solution, you can swallow the solution on its own or stir it into a few spoonfuls of water. Drink the diluted solution immediately before the Synthroid settles.[5]
    • It's important not to dilute the medication in juice or milk since these can reduce absorption.

    Tip: If you've been hospitalized for hypothyroidism, your doctor may prescribe an intravenous Synthroid drip.

  2. 2
    Swallow or crush a Synthroid tablet. If your doctor has prescribed tablets, you can use water to swallow the Synthroid tablet whole. If you have difficulty swallowing tablets, crush the tablet and stir it into 1 to 2 teaspoons (4.9 to 9.9 ml) of water. Drink the mixture immediately before the Synthroid has a chance to settle to the bottom of the water.[6]
    • In some cases, your doctor may recommend taking the Synthroid whole. Always follow your doctor's dosing directions.
  3. 3
    Take Synthroid once a day on an empty stomach. The acidity of your empty stomach increases the absorption of the medication, so take the medication 30 to 60 minutes before the first meal of the day. If you prefer to take the medication in the evening, wait 3 to 4 hours after eating dinner before taking Synthroid.[7]
    • To make the medication more effective, always take it at the same time of day.
  4. 4
    Take only 1 dose of Synthroid at a time. If you miss a dose, take it as soon as you remember unless it's within 2 hours of taking your next dose. You shouldn't take 2 doses at the same time. If you take too much Synthroid, you may experience rapid heartbeat, muscle spasms, headache, or shortness of breath.[8]
    • This is especially important if you're also taking other weight-loss medications or appetite suppressants.
  5. 5
    Don't eat foods that prevent your body from absorbing Synthroid. You shouldn't eat grapefruit or grapefruit juice, soybean flour, walnuts, and high-fiber foods. These foods make your body absorb less Synthroid.[9]
    • You should also stop taking supplements or antacids that contain iron or calcium. If you must take them, wait 4 hours after using them to take Synthroid.
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Method 3 of 3:
Combining Synthroid with Lifestyle Changes

  1. 1
    Set realistic weight loss expectations. Remember that Synthroid is used only for confirmed hypothyroidism cases and isn't regularly prescribed as a weight loss treatment, so there's no guarantee that you'll lose weight. In a recent study, only about half of people taking Synthroid noticed weight loss and the amount they lost was between 8 and 9 pounds (3.6 and 4.1 kg).[10]
    • If you've also been diagnosed with obesity, talk with your doctor about steps to manage your weight.
  2. 2
    Eat nutritious meals that contain fresh produce, protein, and whole grains. Include at least 3 to 5 servings of fruits and vegetables in your daily diet. To get protein, eat lean meat, nuts, low-fat dairy, or legumes and choose whole-grain products instead of white or processed ones. Making nutritious choices means your body gets a variety of vitamins and minerals every day.[11]

    Tip: Work with your doctor to set a daily calorie goal that will help you lose weight. Remember that although it's important to cut calories when you're trying to lose weight, you need to eat a nutritionally balanced diet.

  3. 3
    Cut back on processed foods and sweets to reduce your calorie intake. If you frequently eat fast food, processed foods, such as crackers, cookies, or chips, and sugar-rich foods, try to limit them in your diet. These foods pack on calories that don't offer the nutritional benefits that fresh produce, lean protein, and whole grains do.[12]
    • If you're struggling to stop eating sweets or processed foods, make a goal of reducing the amount you eat. For example, if you usually have dessert every night, limit it to 3 times a week.
  4. 4
    Spend 75 to 150 minutes a week doing moderate to vigorous exercise. Burning calories is an important factor in losing weight. Aim for doing 75 minutes of intense aerobic activity a week or 150 minutes of moderate aerobic activity. If you prefer, do a mix of both. Aerobic exercises include:[13]
    • Walking or hiking
    • Swimming
    • Running or jogging
    • Yard work
    • Stretching
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      Tips

      • Store your Synthroid at room temperature and away from moisture or direct sunlight.
      • Since hypothyroidism is a lifelong condition, it's important to regularly check in with your doctor, especially as you age, if you become pregnant, or go through menopause.

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      Warnings

      • Always keep medication out of children's reach. Contact emergency services or a poison control center if a child takes any Synthroid.
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      About This Article

      Doctor of Osteopathic Medicine
      This article was co-authored by Erik Kramer, DO, MPH. Dr. Erik Kramer is a Primary Care Physician at the University of Colorado, specializing in internal medicine, diabetes, and weight management. He received his Doctorate in Osteopathic Medicine (D.O.) from the Touro University Nevada College of Osteopathic Medicine in 2012. Dr. Kramer is a Diplomate of the American Board of Obesity Medicine and is board certified.
      1 votes - 100%
      Co-authors: 4
      Updated: April 11, 2020
      Views: 373
      Thanks to all authors for creating a page that has been read 373 times.

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