T3 (Cytomel) Overview – What To Expect

T3, also known as Cytomel, Liothyronine Sodium, and Triiodothyronine, is one of the most commonly misunderstood drugs in not only bodybuilding, but in the medical community.

I have spoken with several individuals who have had major issues with fat loss, and having a weak metabolism who actually were walking around for years with an undiagnosed Thyroid deficiency (hypothyroidism).

Unfortunately, the method used to diagnose hypothyroidism, and autoimmune disorders that cause hypothyroidism is completely flawed, and 99% of physicians are utterly clueless as to what they are doing, or what their patients need to get healthy.

Sorry for the rant, but Thyroid hormones are a controversial topic for me as I have seen far too many doctors completely screw over their patients by being utterly clueless in the subject.

What Is T3?

In layman’s terms, T3 is the hormone in your body that regulates how fast your metabolism is.

The higher your T3 level is, the more calories you will burn, and the more fat loss potential you will have.

T3 is a drug that is prescribed to those with hypothyroidism, but it is commonly used by bodybuilders and recreational lifters who want to reach a level of body fat that would be difficult to achieve without drug assistance.

That isn’t to say that it is easy to get shredded on T3, it helps though.

Typical T3 Dosages

Determining the ideal T3 dosage will be based upon several factors.

Typically, T3 for bodybuilding/fat loss purposes involves purposely ingesting a supraphysiological amount of T3 in order to increase your metabolism to a level that would otherwise be impossible.

This can be achieved with as little as 25 mcg, however, not all T3 is created with equal quality.

Despite T3 being an inexpensive drug, for some reason, the quality varies wildly between different sources.

Ideally, you’d want to get your T3 from a pharmacy (and prescribed by your doctor of course), as that’s the only way to absolutely ensure it is dosed accurately.

The standard dose for fat loss purposes ranges between 25 mcg – 75 mcg of T3.

The standard starting dosage for treating Hypothyroidism is typically much lower (as low as 5-10 mcg per day), and may be titrated up based on your doctor's recommendation.

Personally, I never go above 50 mcg because T3 can be very catabolic at higher dosages, as it doesn’t discriminate between muscle and stored fat, so the higher your T3 dose is, the more muscle it will rip off your body.

50 mcg – 75 mcg should be more than sufficient for anyone to reap the benefits of a supraphysiological dose of T3.

Side Effects

Once you get to the 100 mcg + range, you put yourself at a much higher risk of side effects like Tachycardia, muscle loss, anxiety, and feeling weak.

Side effects that will be notable at any dose, but will be more pronounced the higher you dose T3 will be increased body temperature, increased hunger, and in some cases (I get this) constant muscle flatness.

By muscle flatness I mean it is a lot harder to get a pump, and your muscles lack that pop that they have when they are properly glycogen loaded and hydrated.

That is one of the first things I look for when I am determining if my T3 is legit or not.

I get a notable increase in body temperature, and I notice I am much flatter at the gym and it’s a lot harder to get a pump.

My appetite starts getting a lot more ravenous once I go above 50 mcg as well.

At 75 mcg I am hungry pretty much all day long.

Offsetting The Muscle Loss From T3

The only way you can offset the catabolism from a high dose of T3 is with anabolic assistance.

Whichever compounds are used to achieve that, the fact remains that a supraphysiological amount of Anabolics will almost always be necessary to maintain 100% of one's hard earned muscle tissue when venturing into the higher dosage range of T3.

Obviously it isn’t mandatory, but you will lose A LOT more muscle on T3 without any anabolic assistance than you would with it.

How Much Fat Loss Can You Expect From T3

I’m going to be completely honest with you as addressing this question specifically is the main reason why I wanted to write this article.

T3 is NOT some magical compound like some portray it to be that lets you eat whatever you want all day long and stay shredded.

Usually the individuals who perpetuate this myth about T3 consider “lean” as hardly visible abs.

For me though, being lean is being shredded at a single digit body fat %.

You CANNOT get to single digit body fat % by eating like crap on T3 just because you are on T3.

You still need to diet hard in a calorie deficit, keep training hard, and do your cardio; T3 will simply magnify how much body fat the body burns up during your cut.

I honestly think I could reach very close to the same body fat % I do during my cutting phases without T3 at all (I’d probably end my cut at 1-2% higher than I usually would), it would probably take me a month longer or so though.

Basically, T3 speeds everything up and makes things a bit easier.

It IS NOT an excuse to eat like crap though.

You can get fatter even on T3 + DNP if you overeat.

Trust me, I have.

Does T3 Suppress Your Natural Thyroid Production?

Yes, taking exogenous thyroid hormone will absolutely stop your natural production.

Basically how your thyroid gland works is it has a stimulating hormone called TSH (thyroid stimulating hormone) that is present at a certain level to signal your thyroid gland how much T4 it needs to produce, which then will get converted to the active form of thyroid hormone (the one we want) T3.

When you take exogenous T3, your TSH plummets to near 0 because your body will recognize that there is already so much T3 in your system, that it has no need to produce any on its’ own.

So your thyroid essentially goes to sleep for the duration of time you are taking T3.

However, once you stop taking T3, your body will recognize there is no longer an excess amount of T3 in your system, and your TSH will skyrocket back up to signal your thyroid gland to start producing thyroid hormone again.

There is NO SUCH THING as complete thyroid shutdown.

Your thyroid will never be permanently destroyed from taking T3, and once you come off of T3, if you had a healthy thyroid to begin with, you will eventually recover to healthy natural thyroid function again.

Typically, this recovery process takes a few weeks, but for others it can take substantially longer.

It is all individually dependent.

Personally, I have never had my thyroid suppressed for more than a couple weeks, even after staying on 50 mcg T3 for nearly a year straight.

Why T3 Is My Favorite Fat Burning Agent

I use it almost every single time I cut because it is one of the few things that works really great, and isn’t a stimulant.

Granted, both T3 and stimulants can create cardiovascular complications if abused, I simply prefer T3 if I had to only choose one thing to use as a fat burner.

I barely even notice T3 aside from slightly increased body temperature and a slightly faster resting heart rate, whereas with Clen my resting heart rate is borderline tachycardic and I can't combine it with any other stimulants that day without fearing some significant cardiovascular disaster.

I also prefer it to DNP simply because DNP makes me feel like I’m dragging so much ass I can barely get myself to the gym to train, and I’m actually twice as flat and my workouts are complete garbage on DNP.

Bottom line, T3 works, but it isn’t a magic pill that will get you shredded overnight.

How To Know If Your T3 Is Legit

Like I mentioned earlier, there are various sources for T3 and their quality varies.

Obviously the best place to get it would be a pharmacy after being prescribed it by a doctor for treating Hypothyroidism if you have it.

However, if you want to assess how potent your T3 is and see if the dose you are using is adequate for whatever you are using it for, then you need to get blood work to see how it is affecting your values, and know how to interpret them rather than trust some arbitrary dosage number that a doctor throws at you (doctors are notorious for doing this with hormone replacement therapy).

These are the main things you want to look at:

50 mcg T3 (Cytomel) Blood Test Results
March 28, 2017 Bloodwork Results

As you can see from my blood work, my TSH and T4 levels are absolutely tanked.

This is because I have so much exogenous T3 in my body from the T3 I’m using, that my thyroid gland has completely gone to sleep (temporarily).

This means that my body is HYPERthyroid (supraphysiological range of T3) during that test.

You want your T3 in range if you are treating Hypothyroidism.

In Canada they won't show you your T3 values in most cases (because most doctors here are clueless how to treat Hypothyroidism or anything hormone related) but if your TSH and T4 are in the toilet, you can be assured that your T3 is sky high (in most cases).

Now, if your TSH was in the normal range or high, then that's a different story.


  • TSH in range = Thyroid functioning as normal and your T3 is probably bunk
  • TSH high and out of range = Thyroid is trying extremely hard to produce more T4 (to ultimately convert to/increase your T3 into a healthy range) becuase:
    • A) You are Hypothyroid at the moment because you either just came off of legit T3 within the last week or two and your Thyroid is in the process of recovering natural function (meaning the T3 you are currently using is bunk)
    • B) Or you have a crappy Thyroid gland and just have terrible natural thyroid production and likely require T4 or T3 to just maintain a healthy T3 level (meaning the T3 you are currently using is bunk)

Disclaimer: The information included in this article is intended for entertainment and informational purposes only. It is not intended nor implied to be a substitute for professional medical advice.


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About Derek

After dedicating over 8 years to extreme self-improvement, I have created "More Plates More Dates" as a one stop shop for helping you to get yourself on the right path to the "best you" possible too.


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