Synthroid Been Tried?

When Synthroid isn’t enough for Hypothyroid people. Of whom there are plenty.

New guidelines from the UK are trying to help doctors navigate the common enough problem of people taking Synthroid being unsatisfied with the drug even though their lab tests look totally normal. This you? 

What do the guidelines on Synthroid say?

If you’re hypothyroid and taking enough Synthroid (aka T4) to make your TSH below 2 and it’s been 3 months, then you can either take more Synthroid to bring your TSH down even further to a safe yet effective level OR you can add a different drug into the mix. A mouthful I know.

Symptoms that don’t improve on Synthroid are:

  • lethargy
  • weight gain
  • mental slowness
  • constipation
  • and feeling cold.

Why do some doctors, myself included, add T3 and some don’t?

Adding T3 to Synthroid has been studied A LOT. When you add all the studies together they don’t seem to show it does much. So many doctors rightfully see that collective evidence as proof they shouldn’t add T3. BUT many of these studies were small, and none of them use the amount of T3 we normally have in our blood.

The anti-T3 docs think that lifestyle could be playing a role in the leftover symptoms people feel while on Synthroid. So they focus on that much to the chagrin and exhaustion of patients only to have these patients find they don’t get anywhere so look for alternative treatments like approaching doctors like me to add T3.

Excuse me while I get a little research doctory here.

Some individual studies have shown a benefit to adding T3 to Synthroid.

There is a condition called Subclinical Hypothyroidism which affects 5-10% of the population. The TSH level is between 5 and 10, but they don’t have symptoms. Every year 5% of these will eventually become symptomatic. This is especially true if blood thyroid antibodies are positive. This is why we test for antibodies to screen if a person has the risk of becoming hypothyroid as their labs straddle the line between normal and abnormal.

That doesn’t mean you’re in the clear if you have negative antibodies because even then there is a 3% per year chance of developing symptoms.

The rest of people with TSH between 5 and 10 will eventually just get better on their own. So if the majority of people normalize, why would a doctor give medication to help? Hence, doctors not wanting to prescribe anything for fear of giving someone something they don’t need, which happens 30% of the time. 30!

Add to this, our TSH floats upwards as we age.

And we know that 30%-50% of people put on Synthroid, who then stop taking it at some point, will have normal TSH.

No wonder patients are looking for more answers as to why they feel the way they do when their lab work looks ok. No wonder docs don’t want to overprescribe. This study melee results in a lot of deserving people who merit a trial of T3, not getting access to it.

If you are taking Synthroid and you do actually have hypothyroidism yet still have symptoms, what could be a problem?

The optimal daily dose in overt hypothyroidism is 1.5–1.8 mcg/kg of bodyweight rounded to the nearest 25 mcg.

Could something you’re doing be blocking your Synthroid?

  • Maybe you aren’t taking enough?
  • You miss doses.
  • You take it near iron tablets, calcium, soy, and caffeine.
  • You take acid blockers.
  • You have a hidden infection like H Pylori (get tested)

Could something about you make you need more than usual?

  • You’re pregnant or taking oral estrogen.
  • You’ve gained weight.
  • You have kidney issues.

Why don’t people like Synthroid only treatment?

  1. Maybe the problem isn’t your thyroid.
  2. Some people genetically need T3 because T4 doesn’t get activated in their body. This group is who we like to treat with T3. The only way to know is to try.

Is T3 for me? Let’s see.

When adding T3, your Mint doctor will carefully adjust your Synthroid accordingly to make room for the T3. T3 is 3-4 times stronger than T4. Adding T3 can dramatically improve some people’s lives. Give it a try. Under our guidance of course.

The decision to start treatment with T3 should be a shared decision between you and your clinician. We will take into account everything written above and tailor a way for you to incorporate the right amount of T3 for you.


Open Access

Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement

Rupa Ahluwalia, Stephanie E. Baldeweg, Kristien Boelaert, Krishna Chatterjee, Colin Dayan, Onyebuchi Okosieme, Julia Priestley, Peter Taylor, Bijay Vaidya, Nicola Zammitt, Simon H. Pearce

Dr. Bobby Parmar ND RAc