Levothyroxine and Brain Fog: What Users Say

• And...
• March 11, 2021

Levothyroxine for Underactive Thyroid "I was taking Levothyroxine 88mg from Walgreens or CVS since I was 18. Now I’m 33. Switched pharmacies to a neighborhood Walmart because it was closer to home back in Sept 2020. They gave me a generic called Euthyrox and said it was the exact same thing, so I trusted them. They just said the packaging was different. They were so wrong! Since September 2020, I’ve been having horrible side effects - muscle aches, pains, and stiffness all the time! Muscle weakness, blurred vision, chest pains, severe acid reflux (GERD-like symptoms). Foggy brain, forgetfulness, and feeling cold all the time. Didn't feel like myself at all! I almost passed out twice last week and had enough! I went to the Dr and she immediately switched me back to my meds from before. Today will be 6 days that I have switched back and my side effects have been subsiding. It was so scary and still is knowing this medication is out there! Please don’t take it. When I almost fainted and had chest pains, that was the scariest part for me."

• joy...
• Taken for less than 1 month
• February 10, 2021

Levothyroxine for Underactive Thyroid "In November 2020, I was diagnosed with low thyroid. My doctor put me on levothyroxine 25 mcg. I also went to Walmart and they gave me Euthyrox. I started taking it on the 11th. After taking it for one week, I began having hip pains that radiated into my legs. My joints ached and burned. I had headaches, low energy, dizziness, confusion, and a foggy brain. I didn't want to move as it hurt. I am a retired nurse and knew the recent change was due to medication. I stopped taking it on the 19th of November. I went to the doctor's office and was told to stop taking it. By Thanksgiving, I was feeling better. It took a few weeks to feel normal again. I have been prescribed Synthroid today and going to try it. It is the brand name of levothyroxine. Hopefully, I can use it. They need to inform people about how dangerous this medication is. I will stop using Walmart. They told me I was sick with a virus and treated me like I was delusional or making it up. I hope they never experience the same as I did."

• Bos...
• Taken for 5 to 10 years
• August 31, 2019

Levothyroxine for Hypothyroidism, After Thyroid Removal "Been on Tirosint for 7 years after switching from other forms of levothyroxine. Been doing great on it, with small dose changes when needed. 4 months ago, was feeling unwell, endo tested me & my TSH was highest it's been since before I started Tirosint. We increased my dose, I'm now worse with full hypo symptoms that are affecting all areas of my life & functioning (intense pain, fatigue, brain fog, menstrual issues, etc.). Just had my thyroid panel & my TSH has climbed HIGHER on a Tirosint dose increase - opposite of what should be happening. Hasn't been this high since my thyroid was removed. I contacted the Tirosint manufacturer to see if the formulation has changed - NO RESPONSE. Will contact all the necessary channels to find out what's going on. It seems obvious that it must be the meds, since my issues coincide with their packaging & capsule sizes changing. I'm livid that they haven't responded. People's lives are at stake. Those without thyroids NEED effective hormone replacement to LIVE."

• Geo...
• Taken for 1 to 6 months
• October 12, 2020

Levothyroxine for Underactive Thyroid "Began taking in early June when Walmart pharmacy refilled my prescription, saying Euthyrox was their new generic and what I would be getting going forward. Within days of taking the first pill, I began to experience headaches that progressively increased in duration and frequency during the four months of taking Euthyrox. Then began the insomnia, tinnitus, heat intolerance, uncontrollable sweating, swelling in the face and eyelids, diarrhea, neck and shoulder pain, blurred vision, fatigue, occasional dizziness, dry mouth, loss of appetite, and brain fog. Stopped Euthyrox almost two weeks ago, and most symptoms have gone away except for headaches and neck pain. Definitely returning to the prior medication, this one was disabling."

• Bee...
• Taken for less than 1 month
• September 1, 2020

Levothyroxine for Hashimoto's disease "I was switched to Euthyrox by the pharmacist at Walmart and did not notice until I got home. I called the pharmacy and asked about the drug, and was told it was the same medication, just another brand. It is not. The first day I took it I had a migraine headache and shortness of breath. I thought it was just me, so I went on and stayed on the medication for 2 weeks, thinking my symptoms would improve. They got worse. By the time I was 2 weeks into taking this medication, I could barely get out of bed. It was like being in a fog all the time, with absolutely no relief. I called back and spoke to the pharmacist, this time getting a different person. He told me that my doctor could specify Synthroid and they would make sure to keep it in stock. I messaged my endocrinologist and he quickly sent in the prescription specifying Synthroid only. I am already feeling better. Please do NOT take this medication."

• Gay...
• October 21, 2020

Levothyroxine for Underactive Thyroid "Horrible drug. Almost landed in ER. Been taking Levothyroxine, generic for Synthroid, for years, a little yellow oval pill with no issues. Called for a refill at Walmart. Arrived home to find boxes of blister packs. Definitely not my normal pills, which came in a pill bottle. Called Walmart and asked about this drug Euthyrox by Merck in Germany. Person who answered the phone said exactly the same, no worries. HE WAS WRONG. Didn't put 2 & 2 together for over 3 weeks as I became sicker, my side effect symptoms were brain fog, strange headache all day, every day, dizzy, heavy pulse in my neck, sudden heatwaves, unsteady on my feet, vision weird, and exhausted. Figured out it was due to changing to this manufacturer. Many reviews from people who experienced the same side effects after Walmart changed to this manufacturer. Walmart should have said something. Doctor gave me a prescription for the old Levo. Immediately stopped taking Euthyrox. Today is the 4th day back on the old pills. 90% better. Called Walmart Corp. & FDA. NOT LIKE OTHER GENERIC LEVOTHYROXINE."

• Hyp...
• Taken for 10 years or more
• November 23, 2019

Levothyroxine for Underactive Thyroid "I am a 57-year-old woman who has hypothyroidism. I've been taking 100mcg of Synthroid for 10 years. I dread taking this pill every morning. I feel like I have an out-of-body experience, blood rushes to my brain, causing anxiety, hair loss, muscle and joint pains, itching all over, brain fog, and insomnia. For the past week, I have been cutting it in half. I will be stopping this crazy cycle. I have lost so much weight just from the anxiety and insomnia. I do not want to have to rely on a synthetic pill and Klonopin, and be told I am depressed. I feel better without it."

• Bre...
• Taken for 10 years or more
• June 21, 2016

For Underactive Thyroid "This medication is used to treat low thyroid hormone levels. I have Hashimoto's. This is an autoimmune disorder where the body attacks the thyroid until it no longer functions properly. Many people with low thyroid hormone levels have this but are not aware because doctors tend to treat with the medication rather than the whole disease. A lot of the people posting claiming side effects are actually describing side effects of LOW THYROID or HIGH THYROID! The medication is simply a replacement hormone and will not make you constipated, have brain fog, anxiety, fibromyalgia, heart palpitations, etc. unless you are taking TOO MUCH or TOO LITTLE of the hormone. A lot of the negative reviews of this medication are absolutely ridiculous!"

• Bob...
• Taken for 1 to 6 months
• October 22, 2020

Levothyroxine for Underactive Thyroid "Walmart switched my levothyroxine medicine without doctor permission. I started taking Euthyrox in May, started having sharp pain, muscle spasm, headache, dry mouth etc. The pain became unbearable. Went to the doctor and had inflammation, high sodium, kidney function decrease, and pain all over. I couldn’t focus as I had brain fog. This medicine should not be sold. Walmart is trying to save a dollars while putting our lives at risk."

• Can...
• Taken for less than 1 month
• October 30, 2020

Levothyroxine for Underactive Thyroid "I had my Levothyroxine prescription refilled at Walmart like 3 weeks ago, and they gave me Euthyrox, saying that it was a new presentation. They said they had changed the name, but it was the same medication. I’ve been having lots of headaches, itchy skin, dry mouth, and loss of focus. I thought I had an allergic reaction to something, but I haven’t changed anything-soap, detergent, lotion, anything. My husband told me it could be the new pills, and now that I read all the comments, I realized that is my problem."

• Jen...
• Taken for 1 to 6 months
• June 9, 2021

Levothyroxine for Hashimoto's disease "I've been on Levothyroxine for over 10 years and haven't had any issues. All my levels have been great. Wal-Mart pharmacy prescribed Euthyrox in place of my Levothyroxine, stating it was the same, and it is NOT THE SAME!! After two months of missed periods, weight gain, brain fog, moodiness, depression, etc., and now my blood work has CONFIRMED my levels are all off balance for the first time in over 10 years!!! DO NOT TAKE THIS MEDICINE!! Wal-Mart, please STOP using this!! My Dr. has switched my prescription to Walgreen's, and I am now back on Levothyroxine once again and throwing Euthyrox in the TRASH!! Beware, it is not the same, and you will be messed up!! Euthyrox should be removed, and I am reporting it everywhere I can report it!!"

• Lov...
• Taken for less than 1 month
• November 23, 2016

Levothyroxine for Hypothyroidism, After Thyroid Removal "I was on levothyroxine for a year after my cancer surgery/thyroid removal. It was the worst year of my life. I was seriously hating life because I hurt every single day. Muscle aches, swelling, every symptom you can imagine. Weight gain was the worst. I fired my endo and waited two months to see the new one. If I wasn't married, I'd propose to the man. In three weeks, my life has changed. I can go to the gym and not feel like I have been hit by a truck. No muscle aches. I have lost 9 lbs. Brain fog is lifting. I sleep better, and I don't feel like a 47-year-old stuck in a 90-year-old body. I will pay ANY amount of money, and I will NEVER go back."

• tan...
• Taken for 1 to 6 months
• September 9, 2015

For Underactive Thyroid "I started taking Levothyroxine around 2 months ago, building up from 50 to 75. Recently had blood test back, and my results have come back as normal now! I went from nearly collapsing while out walking my dog. Having aches and pains. Brain fog, no energy at all... falling asleep at the drop of a hat! Fights with hubby, because I was so fatigued! Was going on like that for years, until Doctor gave me the blood test, and realized it was a medical condition. I thought it was me, just being tired and irritable. Now I am starting to recover, slowly, weight gain. Went from 9 stone to 12.2. 3 stone. now I have to lose all this weight because of hypothyroidism... nightmare! But I feel more awake, more energy, hope this review helps someone!"

• Kat...
• Taken for 1 to 6 months
• September 15, 2016

Levothyroxine for Underactive Thyroid "I was taking Levothyroxin 50mcg for the past 3 months. My initial TSH was 13 when I started Levo; within 2 months, my TSH dropped to 2.5. Although my levels were normal, I continued to have some fatigue, sleepiness upon waking, night sweats, facial flushing, anxiety, and horrible brain fog. I decided to try my sample of Synthroid 50mcg and within a week, the brain fog, night sweats, and sleepiness were gone! I wake up with the most energy I have ever had! I am still experiencing some anxiety and facial flushing which we are monitoring, but overall Synthroid is working for me! I am 32 years old and 9 months postpartum. I also take my dose at night, hours after dinner."

• Smi...
• February 20, 2015

Levothyroxine for Underactive Thyroid "The only problem with Tirosint capsules is the out-of-pocket price... We are low fixed income due to my hubby, who is an Elderly Disabled Vet, and I must be home taking care of him, so nearly $44/mo comes out of the grocery $, Yet I prefer Tirosint capsules over any other thyroid meds I have had because I have not had any negative reaction to it like I have with all the others I have tried, Levothyroxine tablets give me big migraines. With Armour, I have an allergic reaction that makes me feel like a zombie."

• ric...
• August 6, 2020

Levothyroxine for Hypothyroidism, After Thyroid Removal "Many doctors have begun to realize that many people are allergic to the ten or more additives in Synthroid. I had papillary thyroid cancer over 30 years ago. I had surgery, and I have been sick for over 30 years. The brain fog was terrible. I have fired more than 20 doctors over this time. They always said, 'Your lab report says your levels are fine.' On my second visit to a holistic doctor, she changed me to Tirosint, which has no additives. Tirosint is relatively new and is produced in Europe. TRY TIROSINT. Please…. You will not be sorry."

• Sco...
• Taken for 1 to 6 months
• November 7, 2020

Levothyroxine for Hypothyroidism, After Thyroid Removal "I am so glad I came on here to look at reviews for this medication, Euthyrox. I have had horrible headaches, dry mouth, brain fog, dizziness, muscle pain, tinnitus, and neck aches. I went to see my ENT because I thought I had something seriously wrong with me. He is scheduling me to have a CAT scan done. I'm going to tell my endocrinologist about my issues with this medication. Getting off this one and see if my issues subside. I was on a different generic med, but Wal-Mart switched me to this one. Shame on them!"

• Tin...
• January 6, 2023

Levothyroxine for Hashimoto's disease "Tirosint Sol has given a consistency in efficacy. Other 'natural' brands were always being recalled for either too little or too much thyroid. I kept having issues of heart palpitations when the other brands I was taking had too much thyroid, and other times I would be sluggish and have brain fog when there was too little. A month or two later, after the fact, I would get a notice that the batch of thyroid NP or Armor Thyroid was being recalled. It was a roller coaster. So with the Tirosint Sol, it has given me consistency, and the solution I feel is more quickly absorbed. I wish they would come out with something similar to a glucose monitor for thyroid levels so that one could monitor their thyroid hormone levels throughout the day."

• LoL...
• Taken for less than 1 month
• October 23, 2020

Levothyroxine for Hashimoto's disease "I have had Hashimoto's for 8 years. Tried Levoxyl, Synthroid, Armour thyroid. Finally went to generic since they all seemed about the same and the cost was far less. I felt great, very stable TSH, etc. Walmart switched to Euthrox with my last refill, and I feel absolutely horrible. Low energy, weight gain, complete brain fog, and many, many more. Since it was a new med, I alternated it every other day with my old generic and this. Felt okay, so I switched to Euthrox daily and honestly feel as if I am taking NOTHING. Glad to hear it seems to be an almost universal complaint. I plan on visiting Walmart tomorrow to see if there is anything they can do about replacing this horrible medication."

• Ang...
• Taken for 1 to 6 months
• July 27, 2020

Levothyroxine for Hypothyroidism, After Thyroid Removal "I have taken levothyroxine for years, usually Sandoz. My pharmacist changed my script to Euthyrox 2 months ago. I noticed the last 2 weeks my head is in a fog, want to sleep more than usual. I’m very disappointed and will talk to my dr about this."

• Tha...
• Taken for 1 to 6 months
• November 3, 2020

Levothyroxine for Hashimoto's disease "I was on Levothyroxine for three years. Three months ago, Walmart (without permission) changed my prescription to Euthyrox. At the time, I didn't think it would matter, so I took it as I had my previous med. I started having leg and hip pain - then extreme brain fog - tingling and numb extremities - depression. I went to the doctor and was told my levels were within range. The doctor stated he had not heard of Euthyrox. Nothing has changed in my life (other than COVID), but the med. I called Walmart, and they told me they could no longer get Levothyroxine. The pharmacist explained that Euthyrox was much better in foil packs and would not lose its purpose as Levothyroxine would once it was open. After reading other comments, I'm switching back and to another pharmacy."

• Lbj...
• Taken for 5 to 10 years
• January 13, 2018

Levothyroxine for Hypothyroidism, After Thyroid Removal "I'm taking Synthroid - it's a horrible drug. I'm losing all my hair, headaches, insomnia, depression, fatigue, brain fog, etc. This drug sucks, I have no idea why doctors keep pushing this drug. I have a new insurance and doctor, hopefully, I can start taking Armour. If not, I have no idea what's to come."

• Sam...
• Taken for 10 years or more
• July 14, 2019

For Underactive Thyroid "I was diagnosed with hypothyroidism at age 14. I was gaining weight like crazy, feeling tired all the time, and losing my hair. The doctor had performed an ultrasound on my thyroid and discovered my condition and started me on Synthroid. My energy started to get better, and weight started to come down. But I went to a different doctor, and they put me on levothyroxine 88 mg, and it made me feel tired all the time. My skin is drier than normal, and I have constant brain fog. After age 22, I had gained almost 60 pounds after a major injury and couldn't lose it. The doctor wouldn't remove me from levothyroxine at all or recommend any different treatment options for my thyroid hormone or weight loss. So I changed doctors, and I have lost more than 100 pounds in the last 2 years. With the help of medication and the diet, I have been able to maintain it. But I would do anything to change my thyroid meds."

• Jou...
• February 20, 2017

Levothyroxine for Hashimoto's disease "I was started on levothyroxine, then Armour, and my symptoms were worse than before medication. Tirosint literally gave me my life back. Then new insurance made me try Nature-Throid. Back to the same misery that plagued me the better part of the year. Whatever the cause or effect in chemistry, I am immediately changing back. Brain fog, sore muscles, lethargy, fatigue, constant hunger, weight gain. Never again will I try another medicine."

• cat...
• January 7, 2017

For Underactive Thyroid "Been on levothyroxine for about 5 months. Initially 50 mcg. After about a week or two, I immediately felt better. 'Brain fog' was decreased, I felt a lot less tired, a lot less cold. Also, I lost a significant amount of weight (I put on a lot due to an undiagnosed autoimmune thyroiditis). I'd say the worst side effect of this is the massive hair loss initially, and my hair was tangled so easily. I am now on a maintenance dose of 100 mcg. Have bought myself a decent hairbrush and I feel a lot better."