Add active T3 when levothyroxine alone leaves symptoms, dosed and monitored from a full thyroid panel.
$1.30/dayBilled $78 every 60 days
Medication is charged only if your clinician prescribes it.
60-day supply
$1.30/day
Start with a $20 clinician review
Add-on only
The American Thyroid Association found no consistently strong evidence that T4 plus T3 beats levothyroxine alone
Source: Jonklaas J, et al. Thyroid 2014;24(12):1670-1751 (ATA guideline)43% vs 23%
Across 18 studies, 43% preferred T4 plus T3, 23% T4 alone and 30% had no preference; clinical outcomes were similar
Source: Millan-Alanis JM, et al. Thyroid 2021;31(11):1613-1625 (meta-analysis)About 80%
of the T3 circulating in your blood is made from T4 inside your tissues, which is why T4 alone works for most people
Source: Cytomel (liothyronine) prescribing information, clinical pharmacologyFigures come from a professional guideline, a meta-analysis of randomized trials and the brand-name Cytomel label. Combination therapy is a shared decision, and individual results vary.
A clinician-checked T3 add-on, started low and adjusted from timed labs, with your care team a message away.
Clinician review of your full thyroid panel
TSH, T4, T3, reverse T3 and antibodies read alongside your symptoms and current levothyroxine.
Liothyronine from a licensed US pharmacy
A 60-day supply of 5 mcg tablets; your clinician sets the schedule.
Free, discreet shipping
Ships 2 to 5 business days after approval.
Labs before every refill
Timed bloodwork keeps the dose matched to you.
Care team messaging
Report racing heart, tremor or poor sleep and your clinician can change the dose.
Results stored in your Vault
Every panel in one place, so you can compare T3, reverse T3 and TSH across checks.
Free lab panel at month 3
Thyroid Check, as a progress check.
“I already paid for these tests.”
Use the labs you already have
Upload a recent panel; your care team confirms whether it meets the requirement.
“Is this just upselling me another pill?”
No add-on pressure
Your clinician can decide T3 is not right and keep you on levothyroxine alone, and the review is refunded if you are not prescribed.
Thyroid Check
Your body makes most of its active T3 by converting T4. For most people with hypothyroidism, levothyroxine alone restores enough T3 and symptoms settle.
For some people, symptoms continue even with a TSH in range. Your clinician reviews your full panel and may add a small dose of liothyronine, which is T3 itself. Guidelines treat this as a shared decision rather than a routine step.
One small tablet a day. Some members move to twice a day after follow-up labs. Labs are checked before every refill.
TSH, T4, T3, reverse T3 and thyroid antibodies, from a recent upload or a draw near you. Tell us your current levothyroxine dose.
About 10 minutes
They check your T4 treatment, your symptoms and the full panel before deciding whether adding T3 makes sense.
Within 24 hours
If prescribed, free plain-packaged shipping arrives 2 to 5 business days after approval.
Your clinician rechecks labs before every refill and adjusts the dose, and you can message your care team at any point.
Your clinician starts with a small dose and steps up in small increments.
T3 is short acting, so it is often taken twice a day on a set schedule.
A racing heart, tremor, anxiety or poor sleep can mean the dose is too high. Message your care team.
Bloodwork is timed relative to your dose and checked before every refill.
Three things you can do alongside your treatment.
Selenium and zinc help your body turn T4 into active T3, and a healthy gut supports that process. Food comes first, and your clinician advises on any supplement.
Illness, stress, very low calories and inflammation can push T4 toward inactive reverse T3. Reading free T3, reverse T3 and their ratio shows whether that is happening.
Poor sleep and chronic stress are linked with shifts in thyroid hormone. A regular sleep schedule and a calmer evening routine help T3 do its job.
| Feature | T4 plus T3 | T4 alone |
|---|---|---|
| Where it sits in guidelines | An add-on, chosen together with your clinician | The standard first treatment |
| Who it is for | Some people with symptoms that continue on levothyroxine | Most people with hypothyroidism |
| Dosing | T3 is short acting, so it is often split across the day | One tablet each morning |
| Labs | Full panel, with draws timed to your dose | TSH and free T4 |
| What trials show | Symptoms and quality of life similar on average; more people prefer it | The reference standard |
You can take both. T3 is an add-on to levothyroxine, not a replacement for it.
Take 1 tablet (5 mcg) by mouth daily; may titrate to 5 mcg twice daily based on follow-up labs
Thyroid hormone must not be used for weight loss. Doses larger than your body needs can be dangerous, especially alongside other weight loss medication.
Tell your care team straight away if you get chest pain, a pounding or racing or irregular heartbeat, shortness of breath, tremor or sweating or feeling overheated, or you lose weight without meaning to and cannot sleep.
Common side effects
Rare but serious
Do not take this if you have adrenal insufficiency that has not been treated first.
This is not a complete list of side effects. Message your care team about any symptom that worries you.
When symptoms continue on levothyroxine even though TSH is in range and other causes such as iron, sleep and mood have been looked at. It is a shared decision, because trials show no average benefit over levothyroxine alone.
TSH, T4, T3, reverse T3 and the thyroid antibodies TPO and thyroglobulin. Together they show whether T4 is converting well and whether autoimmune thyroid disease is part of the picture.
T3 acts fast and leaves the body fast, so one large dose can cause a spike and a dip. Two smaller doses on a set schedule keep levels steadier.
Yes. T3 is added on top of your levothyroxine, and your clinician decides whether the levothyroxine dose changes. Do not change either dose yourself.
No. The label carries a boxed warning against using thyroid hormone for weight loss, and extra doses can be dangerous. T3 is for people with an underactive thyroid whose symptoms continue.
Reverse T3 can rise with illness, stress, strict dieting and inflammation. Your clinician reads it with free T3 and your symptoms. A high number alone is not a reason to start T3.
60-day supply · $1.30/day · Billed $78 every 60 days
