For patients
Understand your thyroid. Ask better questions.
The butterfly-shaped gland that runs your metabolism.
Your thyroid sits at the front of your neck, just below the Adam’s apple. Its two lobes are joined by a narrow bridge called the isthmus, giving it the butterfly shape you see in our logo. It produces two main hormones, T4 (thyroxine) and T3 (triiodothyronine), which regulate energy, temperature, heart rate, weight, mood, and much more.
Common conditions
- Hypothyroidism: an underactive thyroid. Fatigue, weight gain, cold intolerance, hair loss, brain fog, constipation.
- Hashimoto’s thyroiditis: an autoimmune condition and the most common cause of hypothyroidism in the United States.
- Hyperthyroidism and Graves’ disease: an overactive thyroid. Anxiety, palpitations, weight loss, heat intolerance, tremor.
- Thyroid nodules: very common lumps in the gland; most are benign but all deserve evaluation.
What each number on your lab report means.
A “normal” range is a population average. Ask your clinician about your optimal range, and always look at the full panel together.
| Test | What it measures | Why it matters |
|---|---|---|
| TSH | Thyroid-stimulating hormone, the pituitary’s signal to the thyroid | The standard screening test. High usually means underactive; low usually means overactive. On its own it can miss a lot. |
| Free T4 | The unbound, active form of thyroxine | Shows how much storage hormone your thyroid is producing. |
| Free T3 | The unbound, active form of triiodothyronine | The hormone your cells actually use. Low free T3 with a normal TSH can explain persistent symptoms. |
| Reverse T3 | An inactive form of T3 | Can rise with illness, stress, or dieting and block the active hormone. |
| TPO & Tg antibodies | Antibodies against thyroid tissue | Elevated levels indicate autoimmune thyroid disease (Hashimoto’s). |
| TSI / TRAb | Thyroid-stimulating antibodies | Used to diagnose Graves’ disease. |
There is more than one way to treat a thyroid.
Most patients do well on standard therapy. Some do not, and they deserve access to the alternatives.
Levothyroxine (T4)
The most commonly prescribed thyroid medication. Synthetic T4 that the body converts to T3. Brands include Synthroid, Levoxyl, Tirosint, and Unithroid.
Liothyronine (T3)
Synthetic T3, used alone or combined with T4 for patients who do not convert T4 well or remain symptomatic on T4 alone.
Desiccated thyroid (DTE)
Porcine-derived extract containing both T4 and T3. Brands include Armour Thyroid and NP Thyroid.
Compounded thyroid
Custom-made by a pharmacist with a patient-specific T3:T4 ratio, no fillers, and optional slow release. Currently threatened by the FDA classification.
Learn moreBring this list to your next appointment.
Good care is a partnership. These questions help you and your clinician make decisions together.
Thyroid Freedom · Patient library
There is no one-size-fits-all thyroid treatment.
Six plain-language articles by Brittany Henderson, MD on the real options for treating hypothyroidism, the evidence behind each, and the questions to bring to your clinician.
Start here
Which thyroid medication is right for me?
Levothyroxine, T4/T3 combination, and desiccated thyroid side by side: who each suits, cautions, cost, and the questions to ask.
T4 only
Levothyroxine: how it works, and why some still feel unwell
How brands and formulations differ, the five reasons a normal TSH can still feel hypothyroid, and what the research says.
T4 + T3
T4/T3 combination therapy
What liothyronine adds, who the thyroid associations say may benefit, how a trial is dosed and monitored, and who should avoid it.
Desiccated
Desiccated thyroid: Armour, NP Thyroid, and compounded Thyroid USP
What DTE contains, how the brands differ, why some patients need the compounded version, and the FDA dispute in plain language.
Labs
Reading your thyroid labs
TSH, free T4, free T3, reverse T3, and antibodies: what each measures, why TSH alone is not enough, and how results change on each treatment.
Athletes
Running with thyroid disease
Medication timing around a run, the labs that matter for athletes, heart-rate warning signs, Hashimoto’s and recovery, and a race-week checklist.
Find care
Looking for a thyroid specialist?
New · Thyroid Freedom Run Club
Running on T3 & caffeine? You have a team now.
A free, virtual run club for anyone with a thyroid condition, or anyone who loves someone who has one — any pace, anywhere in the U.S. Monthly challenges on Strava, a place to compare notes on training with a thyroid condition, and walkers are always welcome.
