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Synthroid and Tiredness: What Users Say

Tiredness: mentioned by 33 users (17.3%)

Based on user experiences from 191 Synthroid reviews, the following table shows the most commonly mentioned side effects.

All user comments are moderated by Drugs.com. Each review is verified for relevance and screened for inappropriate content. Side effects are user-reported and not clinically verified.

tiredness 17.3%
hair loss 14.1%
depression 13.6%
fatigue 12.6%
weight gain 12.6%
anxiety 8.4%
insomnia 5.8%
brain fog 4.2%
joint pain 4.2%
pain 4.2%

Reviews for Synthroid

Commonly mentioned side effects
  • Won...
  • Taken for 10 years or more
  • February 16, 2019

For Underactive Thyroid "I was on Synthroid for 10 years. I was in so much pain in my joints, I couldn't function. This is a known side effect of this medicine. My numbers were where they were supposed to be per the doctors, but I still felt tired and my hair was still falling out. After my husband and I did research, we worked with my doctor and switched to Armour Thyroid. Within 6 weeks my pain was gone, I felt better. I wasn't tired and my hair was falling out. No matter what medicine you use - you know how you should feel. Do the research and work with your doctor. Only you know how you should feel. Don't depend on the doctor to tell you."

1 / 10
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  • los...
  • November 20, 2013

For Hypothyroidism, After Thyroid Removal "My thyroid disease was caught by my determination to find the real cause of my sudden physical & mental change. Long story short, I had thyroid cancer twice (2010 & 2012). April 2013 saw a thyroidectomy, followed by radiation 3 months later. It has taken all my strength not to give up. I am finally on 175mcg & my endocrinologist is brushing off my complaints of being depressed over nothing, tired, weak, cold, forgetful, waking up with aching feet. She said 2.1 is in range & Synthroid is the solution. It isn't enough! Either it or my dose isn't agreeing with my body. I'm so tired of being tired. Some days it feels like I have cinder blocks tied to my feet."

3 / 10
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306 Report
  • CB ...
  • Taken for 10 years or more
  • October 25, 2012

For Hypothyroidism, After Thyroid Removal "I had my thyroid removed in 1990 and have been on Synthroid ever since. The dosage has changed over the years. Right now I'm on a dose that requires two pills each morning - the 200mcg plus the 50 mcg. I have to wonder if a lot of the symptoms many of us experience aren't due to the Synthroid, but rather the lack of a thyroid and having to get the hormone from a pill? Maybe it just doesn't ever feel quite the same no matter what brand it is. I am usually tired. I can't get enough sleep. Often am achy too. I have always been prone to anxiety and depression and have been on Effexor for years. That helps with a lot of symptoms I had (night sweats, mood issues, etc.) but still so tired."

10 / 10
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Frequently asked questions

  • ire...
  • October 27, 2011

For Underactive Thyroid "I have been on Synthroid for about 7 years. I am 43 now, but I still feel very tired and have no energy or motivation. My bones feel weak. I have been telling my doctor that maybe I need a higher dosage, but he said no. I suggested changing the medication, but he insisted I am fine. But I know my body. My hair is falling out, it's thin. Maybe a new doctor can help me."

4 / 10
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  • ire...
  • October 27, 2011

For Underactive Thyroid "I have been on Synthroid for about 7 years. I am 43 now, but I still feel very tired and have no energy or motivation. My bones feel weak. I have been telling my doctor that maybe I need a higher dosage, but he said no. I suggested changing the medication, but he insisted I am fine. But I know my body. My hair is falling out, it's thin. Maybe a new doctor can help me."

4 / 10
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  • gfm...
  • Taken for 10 years or more
  • February 2, 2013

For Underactive Thyroid "I have been taking this medication for almost 22 years. My thyroid is dead, the doctor said due to childbirth. I started out on the lowest dosage. The doctor didn't want to shock my body, so I had to cut them in half for 2 weeks and then slowly go up from there. I am now taking 200 mg, and have been for several years now. The medication works well for me. If I miss a day, I can tell, and I feel really tired."

9 / 10
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  • Anonymous
  • March 17, 2020

For Hashimoto's disease "Synthroid is terrible, it gave me an exacerbation of mental health symptoms! Nervousness, restlessness, anxiety, fatigue, constant dark thoughts, and depression. My TSH dropped from 0.50 to 0.02, and still no symptoms of hyper, just the same symptoms of hypo: weight gain, tiredness, and depression. I thought I was losing my mind! Trying to adjust my psych meds, thinking that was the issue, didn't work because it was the levo causing the problem. It's difficult to separate symptoms of mental health problems from thyroid problems because they can be similar. I got a referral from my PCP to see an endocrinologist. They switched me to Armour. Significant improvement. Levothyroxine stinks! I'd rather take no thyroid medication and suffer the consequences than take Levothyroxine."

1 / 10
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More FAQ

  • bby...
  • Taken for less than 1 month
  • November 14, 2016

For Underactive Thyroid "I was just diagnosed with hypothyroidism in the last days of October of this year. My doctor prescribed me 50mcg levothyroxine distributed by Mylan. I was only on the medication for 3 days! The medicine made me so fatigued and tired, I could hardly go through my day without wanting to pass out and go to sleep. And not only that, but my chest was feeling really uncomfortable. It felt like someone had put 20 pounds on my chest and overall having difficulty taking a deep breath. My doctor then prescribed me the brand name Synthroid with only 25mcg. I had energy like I haven't had in a year, but on the third day, I was having shortness of breath, my heart was beating so hard and fast, and I felt so lightheaded. Seriously, scariest experience I have had."

3 / 10
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109 Report
  • Anonymous
  • January 18, 2011

For Hypothyroidism, After Thyroid Removal "I was put on Synthroid after having my thyroid removed due to cancer 6 years ago. I think I've been put on every dosage there is. I have not felt the same since. I'm always tired, I wake up wanting to rip someone's head off, armpits sweat horribly, cry over nothing, depressed, hair loss, always colder or hotter than people around me, no energy, etc. But when I talk to my doctor and explain my issues, I'm told that I'm fine. (I beg to differ, needless to say I'm going to see a new doctor next visit.) Though I'm sure Synthroid is a wonderful medication, it just doesn't seem to be working for me in my opinion... my doctor seems to think differently."

6 / 10
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148 Report
  • Anonymous
  • January 18, 2011

For Hypothyroidism, After Thyroid Removal "I was put on Synthroid after having my thyroid removed due to cancer 6 years ago. I think I've been put on every dosage there is. I have not felt the same since. I'm always tired, I wake up wanting to rip someone's head off, armpits sweat horribly, cry over nothing, depressed, hair loss, always colder or hotter than people around me, no energy, etc. But when I talk to my doctor and explain my issues, I'm told that I'm fine. (I beg to differ, needless to say I'm going to see a new doctor next visit.) Though I'm sure Synthroid is a wonderful medication, it just doesn't seem to be working for me in my opinion... my doctor seems to think differently."

6 / 10
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148 Report
  • Deb...
  • January 7, 2014

For Hypothyroidism, After Thyroid Removal "I had my thyroid irradiated in 2005 due to Graves' disease caused by Hep C treatment (Ribavirin & Interferon). At first, I saw an endocrinologist that prescribed Armour Thyroid, but loss of job and insurance forced me to go to a free clinic, where I received Synthroid. The clinic doesn't seem to understand the difference between experiencing low thyroid levels from naturally occurring hypothyroidism and complete loss of thyroid. My NP says to me, incredulously, 'You take an awful lot of thyroid!', and at that time, I was only taking 75mcg a day. Finally, after three years of 75 to 100mcg, when I felt absolutely crazy (tired, confused, hair loss, cranky, paranoid, angry, enormous weight gain), she now has me on 150mcg which seems not perfect but better."

9 / 10
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  • Anonymous
  • Taken for 6 months to 1 year
  • March 30, 2015

For Underactive Thyroid "While it brought the TSH into the appropriate range, the exhaustion, lethargy, constipation, etc. was unbearable. For 20 hours out of the day, felt drowsy, unmotivated, and sleepy. This is no way to live. Got on Tirosint and what a difference."

3 / 10
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  • Anonymous
  • Taken for 6 months to 1 year
  • March 30, 2015

For Underactive Thyroid "While it brought the TSH into the appropriate range, the exhaustion, lethargy, constipation, etc. was unbearable. For 20 hours out of the day, felt drowsy, unmotivated, and sleepy. This is no way to live. Got on Tirosint and what a difference."

3 / 10
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97 Report
  • Sha...
  • January 19, 2014

For Hashimoto's disease "I've been on Synthroid for over 15 years due to Hashimoto's Disease and also partial thyroidectomy due to a nodule. For anyone who is on the medication and says they are feeling depressed, tired, etc., check into the symptoms of hypothyroidism/Hashimoto's disease as it may be that your medication is not at the right dose. My doctor considers 'normal' TSH to be between 1 and 3, while the AMA lists it as between 1 and 5. When I am at a 4, I do not feel well and have all the symptoms. DON'T just STOP taking this medication on your own as you can have severe side effects. GO back to your doctor and discuss how you feel. I cannot take the generics as they do not work for me. Only SYNTHROID for me! (I'm on 225 a day!)"

10 / 10
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99 Report
  • Anonymous
  • June 8, 2010

For Underactive Thyroid "I've been on Synthroid (Levothyroxine) for about a year and a half now. They've changed my dose 4 times so far and I'm currently at 100 mcg. Once they keep me on a dose for a bit, I feel okay, but with every change I have a few annoying side effects. I can say that if you take it every day like you're supposed to, it will work eventually. You have to be patient, it won't make you feel great right away. It took me about 3 months. But it helped with my lethargy, weight, and even depression. It's pretty good if you take it as prescribed. If you stop taking it suddenly, the effects of hypothyroidism come back pretty quickly and severely, so I recommend taking it as your doctor states."

6 / 10
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123 Report
  • Den...
  • Taken for 1 to 6 months
  • October 16, 2017

For Underactive Thyroid "My doctor prescribed Levothyroxine for low thyroid, and I had been feeling so tired and wiped out. Levothyroxine did help improve my numbers (TSH of 7.5 dropped to 4.5), but I felt awful on it. Everything hurt, and I was so exhausted. After 3 months on Levothyroxine, I asked to try the brand name Synthroid. What a difference! It improved my numbers even more (same dose, TSH decreased to 1.75), and not only that, I felt better. I had energy. My experience is night and day. I know generics are supposed to be equivalent, but I can tell you there is a difference. Synthroid brand works so much better than Levothyroxine. Recommended."

10 / 10
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65 Report
  • Den...
  • Taken for 1 to 6 months
  • October 16, 2017

For Underactive Thyroid "My doctor prescribed Levothyroxine for low thyroid, and I had been feeling so tired and wiped out. Levothyroxine did help improve my numbers (TSH of 7.5 dropped to 4.5), but I felt awful on it. Everything hurt, and I was so exhausted. After 3 months on Levothyroxine, I asked to try the brand name Synthroid. What a difference! It improved my numbers even more (same dose, TSH decreased to 1.75), and not only that, I felt better. I had energy. My experience is night and day. I know generics are supposed to be equivalent, but I can tell you there is a difference. Synthroid brand works so much better than Levothyroxine. Recommended."

10 / 10
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  • Ted...
  • July 31, 2016

For Underactive Thyroid "I feel awful! I have been on this drug for 6 weeks. I have so many side effects. 1. Very tired (no energy). 2. Nausea. 3. Headache. 4. Can't sleep (even if I take a sleeping pill). 5. Always feel hot. 6. Sweating. 7. Clammy skin (have to have the fan on all the time). I live in Canada so it's not that hot. Never felt so sick."

1 / 10
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  • miz...
  • December 30, 2016

For Hypothyroidism, After Thyroid Removal "I ended up with an emergency complete thyroidectomy after an ultrasound revealed the tumors (2 in each lobe of my thyroid) had grown and were the culprit for me having to turn my head to the left to swallow food or even drink liquid. After years of taking levothyroxine, I was put onto the brand name Synthroid. At worst, my levels were 86.4. Yes, you read that correctly. My hair falls out in clumps, I feel tired, exhausted, have body aches and joint pain, and chronic fatigue, etc. Now my routine is to take my Synthroid at bedtime with vitamin C. I wake up fine, I'm down from 325 to 181, and I feel great! Please remember your thyroid takes weeks/months to change, you won't notice anything three days to a month into taking this."

10 / 10
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67 Report
  • pli...
  • October 25, 2009

For Underactive Thyroid "I have taken Synthroid for 23 years. The first 3 years I did okay on it but over the past 20, I started to feel lousy. I'm tired all the time and very irritable. I've taken from 0.050 MG to 0.125. I still feel bad. It's been adjusted at least 30 to 35 times throughout the course of 23 years. I feel totally helpless and hopeless. My doctor will not change my thyroid medication."

2 / 10
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113 Report
  • Anonymous
  • December 10, 2011

For Hashimoto's disease "If you are taking Synthroid and you are still depressed, overweight, or losing hair (all symptoms of hypothyroidism, which this drug treats) then your dose is still not high enough. If your doctor tells you that you are 'within the normal range,' switch doctors - if you are still having symptoms, then your dose should be higher. I have been on this medication for several years now and as long as I'm on the right dose, I feel fine. I know I need an adjustment when I start to get tired and depressed. Those are the two most obvious symptoms for me (as well as hair loss). I have used low-carb diets effectively (New Atkins for a New You is good - has a section for vegetarians) to lose the weight I had gained when my thyroid became inactive."

10 / 10
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88 Report
  • Thi...
  • Taken for less than 1 month
  • April 25, 2017

For Underactive Thyroid "After seeing my OB for some problems with menstruation, I was sent for about 10 different blood tests to check my hormone levels. Let's just say that we found the source of my problem and I was referred to an endocrinologist. She wanted to repeat my TSH level because she said that being at 3.65 was a little high for someone my age. So I went back within 4 weeks to get retested and my TSH was 10.36, and I was feeling it. I was so tired I could barely get out of bed. My headaches were out of control, and I gained about 10 lbs in a month's time. I just started 75 mg Synthroid a few days ago, so I'm feeling optimistic. I feel once we get my pituitary adenoma, thyroid, and my vitamin D under control, I'll be so much better. ADVICE: listen to your body."

6 / 10
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44 Report
  • kit...
  • Taken for 5 to 10 years
  • October 4, 2017

For Underactive Thyroid "I was put on Synthroid 1 year after telling my endocrinologist (he was taking care of my type 1 diabetes) that I think I have low thyroid (it runs in my family). After a year, he finally tested my TSH, which was high, and put me on Synthroid. My TSH came back fine, but I told him my hair was still thinning, my nails were still brittle, my stomach was still swollen, and I got every bug that was within 100 miles. I also developed total exhaustion and only left the house for doctor appointments. I went from 103 lbs. to 130 lbs. He put me on a higher dose and switched me to Levothyroxine (generic for Synthroid), which caused a rash and itching on my face, then on the rest of my body, it felt like a ball in my throat. Changing doctors now."

4 / 10
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  • Hop...
  • Taken for 1 to 2 years
  • May 26, 2023

For Hypothyroidism, After Thyroid Removal "I had my thyroid removed in December 2013 and have not felt like me since it was removed. I have been on Synthroid 100 mcg and am having back and knee pain, terrible chest discomfort, tiredness, fatigue, and shortness of breath, which prevents me from doing daily chores as I would like. Doctors keep saying it has nothing to do with the med, but I beg to differ. Cardiac workup fine; at times cholesterol goes up, glucose and blood pressure go up, and the list goes on. When will the doctors listen to patients and not try to tell them how they feel (because they are not the ones suffering)? Pray that I can find a doctor who has thyroid problems. These drug companies are thinking of their bank accounts and not that of the people who have to take their drugs."

2 / 10
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  • Roc...
  • May 29, 2010

For Underactive Thyroid "I was born with a thyroid condition. I am a 23-year-old female. I did the other brand for a while, and it made me tired, sad, and just made me feel hopeless. I am on Synthroid 88 mcg, and although I sometimes feel sad, my weight is maintained, I'm able to work, and play with my 1-year-old daughter, who, thank God, is healthy. Finding the right dosage is so important and is trial and error. If everything is good and you only have one symptom like sadness... get a hobby, again a close friend is so important and always take your pill!"

9 / 10
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Reviews may be edited to correct grammar/spelling or remove inappropriate content. Reviews appearing to come from parties with a vested interest are not published. This information is not intended to endorse any medication and should not replace the expertise and judgment of healthcare professionals.