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How long does Synthroid take to work?
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How long does Synthroid take to work?

I just took my second dose of Synthroid this morning (25 mcg). I still feel the same. When should I see improvement?

Thanks!
23 Comments Post a Comment
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2192208_tn?1346529432
What is your thyroid condition?? It takes several weeks before it is registered, however u may notice the effects sooner.
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Avatar_m_tn
The 25 mcg is a relatively small amount, probably a starter dosage.  With T4 meds it takes 4 weeks to build up to 90% of its total effect on blood levels.  Symptoms tend to lag somewhat changes in blood levels.  Also, the lag time depends on length of time you were hypo and the severity.   So a lot of patience is necessary for hypo patients.  

To try and give you a better answer we need to also know the results of thyroid related tests, and also their reference ranges shown on the lab report.  Another bit of info that would help is your symptoms.

Has the cause of you being hypo been determined?  

Have you been tested for Vitamin D, B12 and ferritin?

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Avatar_m_tn
My results:

TSH: 1.61 (0.50-2.50)
Free T4: 1.22 (0.89-1.76)
Free T3: 3.7 (2.3-5.0)
Total T3: 1.13 (0.60-1.81)

Anti-TPO AB 57.5 (0.0-28.0)

Although my results are within the normal ranges, my endo perscribed me Synthroid to treat my hypothyroid-like symptoms. (Headaches, lightheadedness, fatigue, dry skin, eyes, mouth, hair, lethargy, etc.)

My b12, iron, and ferritin are all normal. I have low D, which I am currently supplementing.

Thank you so much!!!
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Avatar_f_tn
It should take about 6 weeks for you to feel the effects of your synthroid.  Do you take it first thing in the am?  I try to wait about an hour to eat.  Also, taking supplements, you should wait about lunchtime to take any vitamins/minerals.  Eating a breakfast high in fiber could also reduce to absorbtion of synthroid.  Just some thing I have encountered.  How much vitamin D3 are you taking?  That can affect you as well, seeing how synthroid can deplete your D3.  My endo "prescribed" 5000 IU a day.  Hang in there!!  It will kick in and you will be feeling back to normal soon!! :)
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Avatar_m_tn
The TPO ab test shows thyroid antibodies consistent with Hashimoto's Thyroiditis, which is the most common cause of diagnosed hypothyroidism.  With Hashi's your autoimmune system produces antibodies that attack the thyroid gland until, after an extended period, the gland is destroyed.  Along the way, thyroid hormone output is gradually diminished and has to be replaced by thyroid meds.  

It is a very good sign that your doctor has prescribed meds for you already, apparently based on your hypo symptoms.  Many doctors treating Hashi's patients base their decision to medicate, or not, on TSH.  That simply does not work.  Other doctors will tell you that a thyroid test that falls anywhere within the range is adequate for you.  That is also wrong.

A good thyroid doctor will treat a hypo patient clinically by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels.  Symptom relief should be all important, not just test results.  

So it is very good that you were tested for Free T3 and Free T4.  Free T3 is the most important because it largely regulates metabolism and many other body functions.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  Many of our members report that symptom relief for them required that Free T3 was adjusted into the upper third of its range and Free T4 adjusted to around the middle of its range.  

I am also glad that you were tested for Vitamin D, B12 and ferritin.  Hypo patients are frequently low in those areas.  If you don't mind, I would like to see the actual results for those and their reference ranges as shown on the lab report.
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Avatar_m_tn
Vitamin D: 19.7 (30.0 - 100.00 ng/ml) I'm taking 2,000 IU Vitamin D for this

B12: 673 (211 - 946 pg/ml)

Ferritin: 96 ng/ml (30-400 ng/ml)

Thanks!
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Avatar_m_tn
I have hypothyroidism (was diagnosed about 15 years ago) and in the past year I started cutting back my synthroid dose because I was having uncomfortable symptoms which I associate with taking too much synthroid (such as feeling shaky and like I can't stay still and the only thing that can slow me down is eating a ton of food). I had my TSH checked in January (9.2), March (8.5) and August (last week) (7.5) and have been gradually upping my dose to get back into the normal TSH range without the yucky symptoms I had last fall. A few days ago I started having that familiar nausea of pregnancy and am now a day late on my period. It has been about 14 days since conception and now I'm very worried about going into the first trimester of a pregnancy with an elevated TSH. I have two normal healthy children but during those pregnancies my TSH was normal at the start and my OB continued to monitor it during that time. For years I was on 88mcg levothyroxine but since last December I cut my dose back a lot. In the past few months I have been taking 50mcg every other day and 44 mcg every other day. Now, I know I need to increase my dose but am wondering how much I should increase it to make sure that I lower my TSH as soon as possible for the pregnancy. If anyone has experience with this, please let me know. I have been reading all these articles about the effects of elevated TSH during the first trimester and mental retardation and low IQ in infants and it is making me feel pretty upset.
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Avatar_f_tn
I started experiencing transient side effects in the first week and it took me 3 weeks to notice a lessening of my symptoms.

The first thing to disappear was the cold intolerance.
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Avatar_m_tn
Hi ipad135, just wondering whether taking the synthroid helped with your symptoms when you had "normal labs". I have almost exactly the same thyroid levels but have very high Thyroid antibodies (close to 250). I've been having various hypo symptoms like cold intolerance, fatigue, muscle weakness and (most troubling) a swollen tongue (which apparently is a hallmark of hypothyroidism). I'm thinking of asking to be medicated. Did you feel better on the synthroid?
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Avatar_f_tn
I was wondering how everyone is doing now.  My endo just last week upped my synthroid from 112 mcg to 125 mcg because I was having bad symptoms ie dizziness nervousness pulps and headaches. Can anyone tell me how long it takes for the changes to be felt? Unfortunately I am feeling worse :(
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Avatar_m_tn
Please post your thyroid related test results and reference ranges shown on the lab report so that members can assess the adequacy of your testing and treatment.  
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Avatar_f_tn
I too was recently diagnosed with hypothyroidism and really do not understand the implications yet.  The results that I have is a TSH of 7.78.
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Avatar_m_tn
TSH is a pituitary hormone whose function is to signal the thyroid gland to produce thyroid hormone.  TSH is affected by so many things that at best it is only an indicator, to be considered along with more important indicators such as symptoms, and also levels of the biologically active thyroid hormones, Free T3 and Free T4.   That said, when the TSH is high like yours, it is frequently an indication that you are hypothyroid, even though you may not have clearly identified any hypo symptoms yet.  

In order to get a better idea of your status, I suggest that you should request to be tested for the antibodies related to Hashimoto's Thyroiditis, which is the major cause for diagnosed hypothyroidism.  Two tests are necessary, Thyroid Peroxidase and Thyroglobulin antibodies (TPO ab and TG ab).  With Hashi's, the autoimmune system erroneously determines that the thyroid gland is foreign to the body and produces antibodies to attack and destroy the gland.  This occurs over an extended period, resulting in diminishing ability to produce thyroid hormone, and increasing levels of TSH.  If you have Hashi's, it would be a good idea to start on replacement thyroid med, in order to minimize symptoms.

You should also request to be tested for Free T3 and Free T4 (not the same as Total T3 and Total T4), each time you go for tests.   If the doctor resists, just insist on it and don't take no for an answer.  Free T3 is the most important because it largely regulates metabolism and many other body functions.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.

Since hypo patients are frequently too low in the ranges for Vitamin D, B12 and ferritin, I also suggest getting those tests done as well.  When further tests results are available, please post results and their reference ranges shown on the lab report and members will be glad to help interpret and advise further.  
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Avatar_m_tn
My results show:
T4 6.8 ref range (4.1-12.1)
T3 total 1.01 (0.64-1.68)
TSH 2.52 (0.19-4.47)

Vitamin d 25 21.8 which is classified as insufficient
Ferritin 132 (17-400)
B12 607 (241-897)

I am always tired and have memory problems. Do I have hypothyroid? How quickly will I see effect after treatment?
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Avatar_m_tn
Your thyroid test results don't stand out as a hypothyroid problem; however, your T3 and T4 tets are for Total T3 and Total T4.  it would be far better to always test for Free T3 and Free T4, since they are the biologically active portions of Total T3 and T4.  Free T3 is especially important because it largely regulates metabolism and many other body functions.  Scientific studies have also shown that Free T3 correlated best with hypo symptoms.  

Having said that, in view of the symptoms you mention, and that your Total T4 and Total T3 are in the lower half of their ranges, I suggest that you should do some further evaluation starting with getting the Free T3 and Free T4 tests done.  If they also show to be in the lower part of their ranges, then it would be a good idea to discuss your symptoms and test results with your doctor and try to get your doctor to prescribe a therapeutic trial of thyroid medication, as necessary to raise your Free T3 into the upper part of its range and your Free T4 to the middle of its range.

In addition, your Vitamin D is way too low.  It would be a good idea to discuss with your doctor, supplementing with about 2000 I. U. of D3 daily, or as necessary to raise your Vitamin D level to around the middle of its reference range.
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6853719_tn?1385423850
hey I just got diagnosed with Hypo and my TSH results was 3.85. Some people say that is in a normal range, some have told me that the normal has changed to 3? I am so new to all this I just don't even know what to ask or say, can someone please make sense of all this to me, Thanks in advance :)
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Avatar_m_tn
Yes, the reference range for TSH was revised by the AACE, over 10 years ago, from .5 - 5.0 down to .3 - 3.0; however, it seems that most labs and doctors have not yet bothered to accept the new range.  Even more important is that TSH is a pituitary hormone that doctors like to believe accurately reflects levels of the actual thyroid hormones, but in actuality TSH cannot be shown to correlate well with either of the biologically active thyroid hormones, Free T3 or Free T4, much less correlate well with symptoms, which should be the most important consideration.  So please tell us about any symptoms you are having.  

Also, have you been tested for Free T3 and Free T4?  If not, then you should request both every time you go in for tests.  If the doctor resists, just insist on it and don't take no for an answer.  Free T3 is the most important because scientific studies have shown that it correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  In addition, if your TSH is indicative of hypothyroidism, the most likely cause is Hashimoto's Thyroiditis.  To test for that, you need to test for both Thyroid Peroxidase and Thyrlglobulin antibodies.  Those two tests are shown as TPO ab and TG ab.  

Since many hypo patients are frequently too low in the ranges for Vitamin D, B12 and ferritin, you should also request those tests.  Then when you have the suggested test results, please post results and reference ranges shown on the lab report and members will be glad to help interpret and advise further.  

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Avatar_m_tn
Sorry about my typing, that should be Thyroglobulin antibodies.
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Avatar_f_tn
I am also facing a similar problem, I went to see a doctor early Jan because of my irregular periods and some other symptoms such as tiredness, headaches every morning etc. I was diagnosed with Hypothyroidism and my test results are as below. It has been around 20 days that I have been taking Synthroid 88mcg but still did not get my period back(stopped 2months back). I am very worried as I am 26yrs old and do not have a baby yet which we were about to plan soon. How much time do you think it will take for me to get my period back and when will things be normal again?
Any advice would be helpful.
Thanks in advance.

Free T4 0.8-2.2 ng/dL 0.9
TSH 0.450-5.100 uIU/mL 12.300

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Avatar_m_tn
There is no good way to estimate those things, without further info.  You really need to make sure they always test you for both Free T3 and Free T4 each time you go in for testing.  Free T3 is the most important because it largely regulates metabolism and many other body functions.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  

Twenty days is not long enough for your serum T4 level to fully reflect the dose you started 20 days ago.  In addition, you can't know how well your body is converting the T4 to T3 without testing Free T3.  

When you do go back for testing, I suggest that you should also test for Vitamin D. B12, selenium and ferritin.  Hypo patients are frequently too low in the ranges for those as well.  

When you have further test results, please post them along with reference ranges and members will be glad to help interpret and advise further.
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Avatar_m_tn
Did your doctor test your FSH? Hashimotos and Premature Ovarian Failure (they have another name for it now) unfortunately often times present themselves at the same time-they did for me. I would find a reproductive endocrinologist pronto!
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Avatar_f_tn
I have had a number of symptoms of hypothyroid in the past year and a half. I have always wondered if I had thyroid problems because there are some symptoms I have always had, but since getting cold easily and cold hands/feet aren't a super serious issue, I have just dealt with it. BUT starting within the past year I have also had these weird headaches, feel tired, still sensitive to the cold, dry skin, REALLY BAD memory problems, at first my periods were heavy at times but now are half the length of time and light, retaining water, and I have gained just under 20 lbs in 18 months. For about a year I have been trying to lose/prevent more weight gain by exercising more and making diet changes, although I never really ate unhealthily, yet I keep GAINING weight and can't even stop that from happening. I currently am up to an hour in the gym lifting weights, biking, and walking the treadmill (interval training) almost every day except on the days when I feel so dead that I can't make myself go. I went to my doctor last week, and she tested my thyroid. Here are my results:

No thyroid antibodies,
Free T4, .81 (.52-1.21)
Free T3 3.08 (2.2-3.8)
TSH 1.35 (.34-5.66)
My metabolic panel was normal, CBC was normal, cholesterol and triglycerides all normal.
My doctor didn't request vitamin D this time, but in the past it was low-ish in August 2012, which for living in the south and being someone who loves being outside by the pool, is strange to me.

I do take a multi-vitamin, Stress B Complex, fish oil, biotin (my hair was falling out early on when this all started happening and taking this has helped a LOT even though it's already in the B complex and multi), and this week I added magnesium. I try to take them every day, but sometimes I forget.

I am wondering if my symptoms are thyroid related or may be related to estrogen dominance? From reading previous posts, it sounds like maybe my T3 should be a tiny bit higher, but I am confused between what I see posted on here and what the normal ranges are listed as being. A lot of the symptoms on estrogen dominance are similar to hypothyroid so I am wondering if I should have my hormones tested as well.

My doctor started me on 25 mcg of synthroid a couple of days ago, but I'm not sure if it will help or how long it would take to know it isn't helping, if there is something else going on...

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Avatar_f_tn
Hi. I've just been 'diagnosed' with hypo thyroidism & started synthroid.  I say this with  " ", because my Dr felt like my labs were normal although I've complained of symptoms associated  with it (sluggish, brittle nails,memory issues) & these were my labs at my physical:  

February 2014
TSH: .5 - 5.2. Mine is 6.09.
Free FT4: .8 - 1.8 Mine is 1.1

Past results were:
Sept 2012, TSH 2.15, FT4: 1.1

Sept 2011, TSH: 1.65, FT4: 1.3

July 2010, TSH: 2.03, FT4: 1.0

A jump from the 2.0 range to 6.0+ seems significant to me.
It also runs in the women in my family (grandmother , mother, mothers sister (aunt) and her daughter (my cousin).  I'm really hoping to start feeling better as I just started taking it. I go back in 6-8 weeks to check my blood work tested again.  Any thoughts are appreciated.  Thank you!
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