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Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 2:30 am
by TropicStrength
My TSH is 2.5, but my Free T3 is at the very bottom of the range. I feel sluggish. Is this "functional" hypothyroidism?
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 3:40 am
by AndeanLifter
Are you in a deep calorie deficit? The body will downregulate T4 to T3 conversion to save energy.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 4:30 am
by MedellinMuscle
Check your Selenium and Iodine intake. Those are co-factors for the deiodinase enzymes.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 5:20 am
by CaliFlex
What about Reverse T3? If that is high, it's blocking your Free T3 from working.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 6:10 am
by LatinoBulk
Cortisol is the main driver of high Reverse T3. Are you overtraining?
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 6:50 am
by TropicStrength
I have been pushing it hard. 6 days a week, heavy loads. Maybe a deload is overdue.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 7:35 am
by AndeanLifter
Try taking a full week off and bumping your carbs. Carbs are essential for thyroid conversion.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 8:15 am
by MedellinMuscle
Insulin helps the liver convert T4 to T3. Low carb = low T3.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 8:55 am
by CaliFlex
I learned that the hard way. Keto killed my metabolism.
Re: Thyroid Optimization: T3/T4 Ratios
Posted: Sat Jan 24, 2026 9:40 am
by LatinoBulk
The scale moves down but your energy moves to zero.