How to Take T3 For Weight Loss

Let’s start with what many doctors won’t tell you:

T3 is the most active and powerful thyroid hormone in your body and is far more potent than the T4 found in levothyroxine.

For this reason, it’s probably the best (or second-best) thyroid hormone you can take for weight loss.

For purposes of this article, I’m going to assume that you already know most of the basics… that T3 boosts your metabolism (1), helps generate heat production (2), causes you to burn more calories (3), revs up cellular energy, and so on.

And instead of focusing on that, let’s talk about why you are here:

How to use T3 for weight loss.

1. Start Low and Go Slow

Because T3 is so potent, the cardinal rule is to start low and go slow.

This simple but effective approach to T3 dosing allows you to minimize side effects while maximizing results.

Remember:

As much as I know you want to lose weight as quickly as possible, you won’t do yourself any good by trying to rush your results and kicking off a chain of events leading to problems.

Instead, here’s what you’ll want to do:

• Starting dose: Most thyroid patients do best starting at a relatively low dose in the range of 5-10 mcg. Remember, this is just your starting dose.
• Titration: From your 5-10 mcg starting dose, you can then increase your dose by 5 mcg every 10-14 days (1-2 weeks), as tolerated. This slow increase is important because T3 builds up in your system over time and can hit you like a tidal wave if you aren’t careful. As far as whether or not you tolerate it, you’ll be able to determine that based on some markers that we will discuss soon (lab tests, resting heart rate, and body temperature).
• Maximum dose: Most thyroid patients will find that their sweet spot is somewhere between 25 mcg and 50 mcg per day, but this is just the average. I’ve seen some patients need doses as low as just a few mcg per day and some higher than 50 (though when you need doses that high it usually indicates you’re missing something).

Starting too high and pushing your dose up too quickly is the #1 mistake I see when beginning T3.

2. Take it Correctly

In order for your T3 to work, you must be taking it correctly.

This means:

• Taking it on an empty stomach (2-4 hours away from food)
• Taking it away from supplements by at least 30-60 minutes (4 hours if taking iron or calcium)
• Taking it at the right time of day (both morning and evening work)
• Taking it at the same time every single day without missing a day (you need your T3 levels to stay consistently high if you want it to work)
• Take it only with water (avoid juice and especially coffee/caffeine)

3. Split Your Dose if Needed

Compared to T4, T3 has a much shorter half-life.

If we want to get technical, T4 has a half-life of 5-7 days (4) versus 18-24 hours for T3 (5).

Due to T3s powerful impact on certain tissues (such as your heart (6)) and its short half-life, many thyroid patients benefit from mult-dosing or split-dosing schedules.

Don’t worry, this may sound complicated but it isn’t.

For example, let’s say you’re on a dose of 25 mcg per day.

In this setting, you might take:

• 15 mcg first thing in the morning
• And another 10 mcg right before you go to bed

You could split this up into a 60:40 ratio (15 mcg & 10 mcg), a 50:50 ratio (12.5 mcg & 12.5 mcg), or even a 75:25 ratio.

You’ll need to figure out what you tolerate and what works best for you with some experimentation.

This dosing schedule allows for more sustained T3 in your body throughout the entire day which means more continual cellular stimulation.

But, and this is a big but, split dosing is not always needed nor is it required.

Due to how T3 impacts genetic transcription (it changes the production of enzymes in your cells), there’s evidence to suggest that once-a-day dosing is perfectly fine.

So don’t get too caught up in multi/split dosing schedules unless you find you need it to control your symptoms.

4. Track your Progress Correctly

As obvious as this may sound, you need to make sure you’re tracking your progress correctly.

You might think all you need to do is check the scale and watch the pounds shed off.

If the scale is moving downward then your T3 is working, if it isn’t, then you need to make changes.

While that can sometimes work, it’s far more accurate to take body measurements.

Checking body measurements helps you take into account the simultaneous building of muscle mass that can occur with T3 use.

Imagine if you were to both lose 5 pounds of fat but gain 5 pounds of muscle at the same time.

The scale wouldn’t move, but your body would look and feel better.

This scenario happens often with T3 use and must be accounted for.

So throw out your scale and instead focus on body measurements like these (at least in the beginning).

5. Monitor Your Symptoms, Weight, and Labs

No matter what dose of T3 you are taking, you need to be monitoring and tracking both your progress and some other variables:

• Daily: Either Basal body temperature (first thing in the morning), or resting heart rate (use a wearable device), or, preferably, both. These aren’t 100% required, but they are very helpful when determining your dosing.
• Weekly: Body measurements OR progress pictures, your weight (averaged on the scale over a 7-day period), and changes in your symptoms (good or bad).
• Every 8-12 weeks: Thyroid labs including TSH, Free T3, Free T4, and reverse T3 (not always required, but it is helpful to get).

What may surprise you is that your clinical symptoms and physiologic markers (like body temperature) are often much more important than your thyroid lab tests.

But you do still want to get your labs tested to keep an eye on your TSH to make sure you aren’t accidentally overdosing yourself.

6. Combine With Diet & Exercise

If you think you’re going to take T3 and experience significant weight loss without changing your diet or exercising regularly, think again.

Will it help rev up your metabolism if you don’t do these things? Sure.

Will it help you lose SOME weight if you do nothing else but take T3? Sure.

But you’ll get a multiplicative effect when you combine it with some basics:

• A whole-food thyroid-friendly diet: Use my perfect thyroid diet.
• Sufficient protein intake: Aim for at least 100 grams of protein each day (use my 4x thyroid weight loss formula).
• Sufficient carbohydrate intake: Aim for at least 100 grams of carbohydrates each day (again, see my 4x thyroid weight loss formula)
• Deep and restorative sleep: At LEAST 7 hours per night, but preferably 8 if you can get it. This is incredibly important. See this resource if you struggle with sleep.
• Additional thyroid-boosting supplements: Supplements like fat burners and berberine can help you lose weight about 20% faster.

Troubleshooting & Other Important Considerations

If you aren’t getting the results that you think you should, here are a few potential reasons:

1. Dose is Everything

With T3, dose is everything.

I can’t tell you how many people I’ve run into who have told me that T3 doesn’t “work” for them, only to find out their dose never exceeded 5 mcg.

If that’s you, let me be the first to tell you that 5 mcg is considered a baby dose of T3 and will likely have zero impact on most thyroid patients.

Unfortunately, if you want T3 to work, you’re going to need to be prepared to do some busy work when it comes to dose management.

In fact, this was probably 80% of what I did when I was prescribing it.

It’s not as hard as you might think, though, because an optimal dose of T3 is one that:

• Eliminates all of your low-thyroid-related symptoms.
• Improves your resting heart rate to around 70 beats per minute.
• Increases your basal body temperature to 98.6 degrees.
• Promotes gradual, but sustainable weight loss as measured by body measurements and your weight on the scale (averaged over months, not days or weeks).
• Does NOT cause hyperthyroid symptoms.
• Maintains your TSH in a low-ish, but non-suppressed range.

Getting there isn’t always easy, but it’s always worth it.

2. Are You Taking It Alone?

Contrary to what you might have read online, thyroid patients do better when taking a combination of thyroid hormones, including T4, T3, and T2.

It’s trendy to hate levothyroxine, and I get why, but the reality is that the T4 found inside of it serves a purpose.

And that purpose may be the difference between you losing weight while taking T3 or not.

The same information applies to T2 thyroid hormone which has been shown to support the cellular action of T3 (7).

If you’re not seeing results with T3-only therapy, then try combination therapy:

• T4 – Your T4 dose should be about 80% of your total dose.
• T3 – Your T3 dose should be around 20% of your total dose.
• T2 – Your T2 dose should be about 100-200 mcg per day.
• Thyroid Glandulars – You can supplement with thyroid glandulars to get additional enzymes, co-factors, and pro-hormones to further support thyroid function.

Just like T3 dosing, thyroid combination ratios range from 10:1 (Your T4 dose is 10x that of your T3 dose) to 1:1 (T4 and T3 dosing are equal) and everywhere in between.

3. High Doses May Be Counterproductive to Weight Loss

Contrary to what you might expect, taking excessive amounts of T3 can actually hinder weight loss. When T3 doses are too high:

• You may push yourself into a catabolic state (which is a state of muscle breakdown) thereby paradoxically reducing your metabolism instead of increasing it.
• Excess T3 may push your body into creating reverse T3.
• Your body may develop a cellular resistance to T3 thyroid hormone.

Remember:

More is definitely not better when it comes to T3. Your goal should be to optimize your dose.

4. You’re Missing Something

Lastly, if you aren’t losing weight, then you might just be missing something.

This may sound like heresy, but here’s the reality:

There are many other factors that can influence your weight aside from your thyroid.

Is your thyroid one of the most important? Yes, but just taking T3 won’t make up for things like:

• Uncontrolled sleep apnea (8).
• Metabolic syndrome that isn’t being properly addressed by your diet
• Constant unaddressed stress.
• Over or under-exercising your body without allowing it to recover.
• Additional hormone imbalances (menopause, andropause, etc.).

For most thyroid patients, taking T3 and losing weight will solve or at least improve these issues, but there will always be situations in which they need to be addressed in conjunction with your thyroid.

T3 Supplements VS T3 Medications

One of the biggest downsides to T3 medication is that it can be difficult to obtain.

You may be able to get your doctor to prescribe you 5 mcg of liothyronine or Cytomel, but it’s going to be a lot tougher to get them to prescribe you 25 mcg or more.

This is where T3 supplements step in.

They provide your body with the vitamins and nutrients it needs to support the natural production of T3.

And if you’re serious about losing weight, I’d strongly recommend that you use both T3 medications and T3 supplements at the same time, due to their synergistic effects.

Here’s what works best:

• Zinc + Selenium
• Guggul extract
• T2 thyroid hormone (as 3,5 diiodo-l-thyronine)
• Ashwagandha

Combine these with your T3 medication and you’re off to the races.

Dealing with Side Effects

T3 is powerful and up to 25% of thyroid patients can expect to experience some minor symptoms when they take it.

Some of the most common side effects include:

• Heart palpitations: Usually indicates the dose is too high or was increased too quickly.
• Anxiety or jitteriness: May require dose reduction or slower titration.
• Insomnia: Consider taking your second dose earlier in the day.
• Hair loss: This is usually temporary and resolves within 3-6 months.
• Headaches: Should resolve with time and with adequate hydration (drink more water!).

Most side effects can be managed by:

1. Reducing your dose temporarily (cut back by 5-10 mcg from wherever you were at when the symptom started).
2. Slowing your titration schedule (increase your dose every 3-4 weeks instead of 1-2).
3. Ensuring proper hydration and electrolyte balance.

Serious side effects are rare, but they can and do happen.

To see a full list of potential T3 side effects, see this article.

Final Thoughts

T3 is probably one of the most powerful weight loss tools a thyroid patient can use (with T2 being second) but, like anything, it must be used correctly.

The biggest downside to T3 use is how difficult it can be to obtain.

So if you’re feeling frustrated after reading this because you’ve been unable to get it, I’ve got some good news:

There are things you can do to naturally increase your T3 production.

And I’ve listed them all out in this article (which you should check out next).