Emcitate (tiratricol)
An approved treatment for MCT8 Deficiency.
The same compound appears under different names depending on the context. Here is how to identify Tiratricol wherever you encounter it, plus the key facts at a glance.
- Generic name
- Tiratricol
- Brand name
- Emcitate
- Development codes
- Triac, TRIAC
- Drug class
- Thyroid hormone analog
- Manufacturer
- Egetis Therapeutics
- How it's taken
- Emcitate is a 350 microgram scored tablet that is dispersed in room-temperature drinking water in a 10 to 12 mL syringe and given by mouth or through a feeding tube into the stomach (nasogastric tubes of 6 French or larger, gastric tubes of 12 French or larger).
The first FDA-approved treatment for MCT8 deficiency. The FDA approved Emcitate on September 28, 2026 for peripheral thyrotoxicosis, the harm too much thyroid hormone does to the body, in adults and children with the disease. It lowers the high blood T3 that drives that harm; it has not been shown to improve brain development. It has been approved in the EU since February 2025.
Where Tiratricol fits
The first approved treatment for MCT8 deficiency in the United States, approved September 28, 2026. Its established effect is on the body's thyroid hormone excess, which drives the low weight, fast heart rate and poor muscle mass; the US label is for peripheral thyrotoxicosis, not for the intellectual and motor disability, and Triac Trial II did not show that early treatment changes the brain's course. Standard supportive care, including nutrition, physical therapy and management of spasticity and seizures, continues alongside it.
How Tiratricol works
In MCT8 deficiency the transporter that carries thyroid hormone into cells is missing, so the brain is starved of T3 while the hormone piles up in the blood and overstimulates muscle, heart, liver and bone. Tiratricol is a modified form of T3 that gets into cells through other transporters and does not need MCT8. Once inside, it switches on the same thyroid hormone receptors T3 would. It also feeds back on the pituitary gland, which lowers TSH and in turn lowers the thyroid's own output of T3 and T4. The net effect that has been demonstrated in trials is a fall in blood T3 into or near the normal range, which relieves the body-side thyrotoxicosis: heart rate and blood pressure come down and weight improves. Whether enough tiratricol reaches the developing brain to change the neurological course was tested directly in Triac Trial II, which did not show a statistically significant improvement in gross motor development versus historical controls.
Mechanism: Thyroid hormone analog that enters cells without the MCT8 transporter, activating thyroid hormone receptors while suppressing the body's own T3 production
Side effects and safety
- Boxed warning: not for weight loss. thyroid hormones, including Emcitate, must not be used to treat obesity or for weight loss, which can cause serious or life-threatening thyrotoxicosis
- Too much thyroid effect when starting or raising the dose. fast heart rate, higher blood pressure, diarrhea, sweating, irritability, trouble sleeping and nightmares; if they appear or worsen and do not settle within 2 weeks, the dose is lowered
- Standard T3 blood tests read falsely high. tiratricol cross-reacts with T3 immunoassays, so T3 must be measured by LC-MS/MS; no FDA-authorized LC-MS/MS test exists yet and available tests may vary in accuracy
- Not with primary hyperthyroidism or other thyroid medicines. contraindicated in primary hyperthyroidism; avoid combining with levothyroxine, propylthiouracil, carbimazole or other thyroid drugs
- Do not stop suddenly. the dose is reduced every 2 weeks when stopping, to avoid thyrotoxicosis coming back
- Total T3 by LC-MS/MS about every 2 weeks while the dose is raised, then every 6 months once stable
- Heart rate and blood pressure, especially during titration
- Periodic eye checks for lens changes in children under 8, a precaution based on high-dose studies in dogs
- Clotting tests if also taking warfarin or another oral anticoagulant, whose effect Emcitate can increase
The US label lists diarrhea, vomiting, rash and excessive sweating as the most common side effects, each affecting 5% or more of patients. In the 20-patient randomized withdrawal study, vomiting and rash each affected 10% and sweating 5%; in the 46-patient Triac Trial I, diarrhea affected 13%, vomiting 11%, rash 9% and sweating 7% [3]. Most side effects are what too much thyroid hormone feels like: in Triac Trial I, heart rate rose temporarily in 35% of patients and systolic blood pressure in 26% during dose titration, and 30% had at least 1 side effect of that kind (diarrhea, sweating, irritability, insomnia or nightmares), mostly while the dose was being raised [3]. The label carries a boxed warning that Emcitate, like all thyroid hormones, must not be used to treat obesity or for weight loss, and it is contraindicated in primary hyperthyroidism. There are no data on use in pregnancy; the US label does not forbid it, while the EU label does. In the published Triac Trial I report, 26 serious adverse events occurred in 18 patients and none were attributed to the drug [6].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Tiratricol
Emcitate is a 350 microgram scored tablet that is dispersed in room-temperature drinking water in a 10 to 12 mL syringe and given by mouth or through a feeding tube into the stomach (nasogastric tubes of 6 French or larger, gastric tubes of 12 French or larger). It must not be swallowed whole, chewed, crushed, or mixed with any liquid, food or formula other than water [3]. The daily dose is given once a day or split into 2 or 3 doses. It starts at 175 micrograms a day for patients weighing 10 kg or less and 350 micrograms a day above 10 kg, and rises by the same step about every 2 weeks until total T3 is below the middle of the normal range for age, up to a weight-based maximum of 50 to 100 micrograms per kilogram per day [3]. Blood T3 has to be measured by LC-MS/MS, because tiratricol makes standard T3 immunoassays read falsely high, and once the dose is stable T3 is rechecked every 6 months. The tablets are kept in the refrigerator and protected from light, and the dose is stepped down every 2 weeks rather than stopped suddenly. Egetis expects Emcitate to be commercially available 8 to 10 weeks after the September 28, 2026 approval, through its Egetis RareLink support program and the specialty pharmacy PANTHERx Rare (1-844-434-3847) [2]. Before approval, US patients received it through the expanded access program (NCT05911399).
Availability and cost
Only available as the brand-name product.
An orphan drug for an ultra-rare disease with a few hundred diagnosed patients worldwide, taken daily for life. Egetis had not announced a US price at approval on September 28, 2026; its German reimbursement price took effect August 1, 2026 without the amount being disclosed. With the approval the FDA granted Egetis a Rare Pediatric Disease Priority Review Voucher, which the company expects to explore selling in the 4th quarter of 2026.
Help paying for Emcitate
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Insurance and case manager help
Egetis RareLink, the Emcitate patient support program, works with the specialty pharmacy PANTHERx Rare on medication access, education, care coordination and ongoing treatment services.
For: private insurance, Medicare, Medicaid, TRICARE, no insurance · source
Good to know: Emcitate was approved on September 28, 2026 and Egetis expects it to be commercially available 8 to 10 weeks later. Copay card and free-drug details had not been published at approval; this record will be updated when Egetis posts them.
Clinical trial results
The US label rests on 2 studies [3]. Triac Trial I (NCT02060474), the label's Study 2, was a single-arm, open-label Phase 2 trial of 46 male patients aged 10 months to 66.8 years in 8 European countries and South Africa, published in The Lancet Diabetes & Endocrinology in 2019 [6]. After 12 months, mean total T3 fell from 323.4 to 118.3 ng/dL (4.97 to 1.82 nmol/L), heart rate fell by 8.9 beats per minute and systolic blood pressure by 4.1 mmHg; there was no placebo group. ReTRIACt (NCT05579327), the label's Study 1, enrolled 20 male patients aged 5 to 31; the 15 who reached a stable dose were randomized to continue tiratricol or switch to placebo for 30 days. Mean total T3 rose by 64.6 ng/dL on placebo and was essentially unchanged on tiratricol (a mean change of -0.2 ng/dL), and every patient switched to placebo had a larger rise than any of the 7 kept on the drug. The difference in the rate of T3 change was statistically significant (p=0.034) on a primary endpoint added after FDA comments, while the number who needed rescue treatment (4 of 8 on placebo versus 1 of 7 on the drug) did not reach significance [3][8]. That study is cited in the label and the FDA announcement but is not publicly listed on ClinicalTrials.gov. Triac Trial II (NCT02396459) treated 22 boys under 30 months for 96 weeks and compared gross motor development on 2 measures (the GMFM-88 and the Bayley-III gross motor score) against historical scores from Triac Trial I; on June 19, 2024 Egetis reported that it did not meet its co-primary endpoints, although T3 fell in every patient [7]. The company also submitted a real-world Erasmus Medical Center survival comparison of treated and untreated males that it says showed a significant survival benefit; that analysis has not been published in a peer-reviewed journal as of September 2026.
Development history
Tiratricol is an old molecule, sold in France as Téatrois for thyroid hormone resistance syndrome, and it was repurposed for MCT8 deficiency after Erasmus Medical Center researchers in Rotterdam showed it could bypass the missing transporter in animal models. Triac Trial I began in October 2014. Egetis Therapeutics, a Swedish company, acquired the program through its subsidiary Rare Thyroid Therapeutics and filed with the EMA in October 2023; the European Commission approved Emcitate on February 12, 2025 for peripheral thyrotoxicosis in MCT8 deficiency, and it launched in Germany on May 1, 2025. The European Thyroid Association's 2024 guidelines recommend tiratricol as long-term therapy for all patients with MCT8 deficiency. In the US the FDA granted a rolling NDA review, Breakthrough Therapy, Fast Track, Orphan Drug and Rare Pediatric Disease designations; the NDA was completed on January 29, 2026 and accepted with priority review on March 27, 2026. The FDA approved Emcitate on September 28, 2026, its action date, as the first treatment for MCT8 deficiency in the US, and granted Egetis a Rare Pediatric Disease Priority Review Voucher that the company says it may sell in the 4th quarter of 2026 [1][2].
Explore MCT8 Deficiency trials
Common questions about Tiratricol
▸What is Tiratricol (Emcitate)?
The first FDA-approved treatment for MCT8 deficiency. The FDA approved Emcitate on September 28, 2026 for peripheral thyrotoxicosis, the harm too much thyroid hormone does to the body, in adults and children with the disease. It lowers the high blood T3 that drives that harm; it has not been shown to improve brain development. It has been approved in the EU since February 2025.
▸How does Tiratricol work?
In MCT8 deficiency the transporter that carries thyroid hormone into cells is missing, so the brain is starved of T3 while the hormone piles up in the blood and overstimulates muscle, heart, liver and bone. Tiratricol is a modified form of T3 that gets into cells through other transporters and does not need MCT8. Once inside, it switches on the same thyroid hormone receptors T3 would. It also feeds back on the pituitary gland, which lowers TSH and in turn lowers the thyroid's own output of T3 and T4. The net effect that has been demonstrated in trials is a fall in blood T3 into or near the normal range, which relieves the body-side thyrotoxicosis: heart rate and blood pressure come down and weight improves. Whether enough tiratricol reaches the developing brain to change the neurological course was tested directly in Triac Trial II, which did not show a statistically significant improvement in gross motor development versus historical controls.
▸What are the side effects of Tiratricol?
The US label lists diarrhea, vomiting, rash and excessive sweating as the most common side effects, each affecting 5% or more of patients. In the 20-patient randomized withdrawal study, vomiting and rash each affected 10% and sweating 5%; in the 46-patient Triac Trial I, diarrhea affected 13%, vomiting 11%, rash 9% and sweating 7% [3]. Most side effects are what too much thyroid hormone feels like: in Triac Trial I, heart rate rose temporarily in 35% of patients and systolic blood pressure in 26% during dose titration, and 30% had at least 1 side effect of that kind (diarrhea, sweating, irritability, insomnia or nightmares), mostly while the dose was being raised [3]. The label carries a boxed warning that Emcitate, like all thyroid hormones, must not be used to treat obesity or for weight loss, and it is contraindicated in primary hyperthyroidism. There are no data on use in pregnancy; the US label does not forbid it, while the EU label does. In the published Triac Trial I report, 26 serious adverse events occurred in 18 patients and none were attributed to the drug [6].
▸How is Tiratricol taken?
Emcitate is a 350 microgram scored tablet that is dispersed in room-temperature drinking water in a 10 to 12 mL syringe and given by mouth or through a feeding tube into the stomach (nasogastric tubes of 6 French or larger, gastric tubes of 12 French or larger). It must not be swallowed whole, chewed, crushed, or mixed with any liquid, food or formula other than water [3]. The daily dose is given once a day or split into 2 or 3 doses. It starts at 175 micrograms a day for patients weighing 10 kg or less and 350 micrograms a day above 10 kg, and rises by the same step about every 2 weeks until total T3 is below the middle of the normal range for age, up to a weight-based maximum of 50 to 100 micrograms per kilogram per day [3]. Blood T3 has to be measured by LC-MS/MS, because tiratricol makes standard T3 immunoassays read falsely high, and once the dose is stable T3 is rechecked every 6 months. The tablets are kept in the refrigerator and protected from light, and the dose is stepped down every 2 weeks rather than stopped suddenly. Egetis expects Emcitate to be commercially available 8 to 10 weeks after the September 28, 2026 approval, through its Egetis RareLink support program and the specialty pharmacy PANTHERx Rare (1-844-434-3847) [2]. Before approval, US patients received it through the expanded access program (NCT05911399).
▸Is Tiratricol FDA approved?
Yes, Tiratricol (Emcitate) is FDA approved (2026) for the treatment of MCT8 Deficiency.
▸Is Emcitate FDA approved?
Yes. The FDA approved Emcitate (tiratricol) on September 28, 2026 to treat peripheral thyrotoxicosis in adults and children with MCT8 deficiency, the first FDA-approved treatment for the disease. It has been approved in the European Union since February 12, 2025.
▸What does tiratricol actually do for a child with MCT8 deficiency?
It brings the abnormally high blood T3 down into the normal range, which relieves the effects of too much thyroid hormone on the body: fast heart rate, high blood pressure, sweating, and difficulty gaining weight. In the trials it did not produce a statistically significant improvement in gross motor development, even when started before 30 months of age, and the US approval is for the body's thyrotoxicosis, not the neurological disease.
▸When will Emcitate be available in the US?
Egetis expects it to be commercially available 8 to 10 weeks after the September 28, 2026 approval. Its patient support program, Egetis RareLink, works with the specialty pharmacy PANTHERx Rare and can be reached at 1-844-434-3847. Patients already treated through the expanded access program (NCT05911399) should ask their site how the move to commercial supply will work.
▸How is Emcitate dosed?
The 350 microgram tablet is dispersed in water and given by mouth or feeding tube, once a day or split into 2 or 3 doses. The US label starts at 175 micrograms a day for children weighing 10 kg or less and 350 micrograms a day above that, then raises the dose by the same amount about every 2 weeks until blood T3 is below the middle of the normal range for age, up to a weight-based maximum.
▸Why does Emcitate need a special T3 blood test?
Tiratricol looks enough like T3 that standard T3 immunoassays count it, which makes T3 read falsely high. The US label says total T3 should be measured by liquid chromatography tandem mass spectrometry (LC-MS/MS), and notes that no FDA-authorized LC-MS/MS test exists yet, so results can vary between labs.
▸Is tiratricol the same as Triac?
Yes. Triac is the older research name for tiratricol, short for triiodothyroacetic acid. Emcitate is its brand name in the EU and the US.
▸Why did Triac Trial II fail if the drug lowers T3?
Lowering T3 in the blood and delivering thyroid hormone to the developing brain are 2 different things. The trial was designed to test whether starting tiratricol before 30 months of age would improve gross motor scores compared with historical scores from Triac Trial I. T3 fell in every patient, but the improvement in those scores was not statistically significant. The drug's proven benefit is on the body's thyrotoxicosis, which is what both the EU and the FDA approved it for.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. Food and Drug Administration · 2026-09-28. FDA Approves First Treatment for MCT8 Deficiency. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-mct8-deficiency
- Egetis Therapeutics (GlobeNewswire) · 2026-09-28. Egetis Therapeutics Announces U.S. FDA Approval of EMCITATE (tiratricol) for Patients with MCT8 Deficiency. https://www.globenewswire.com/news-release/2026/09/28/3370311/0/en/egetis-therapeutics-announces-u-s-fda-approval-of-emcitate-tiratricol-for-patients-with-mct8-deficiency.html
- Egetis Therapeutics · 2026-09. EMCITATE (tiratricol) tablets for oral suspension: full prescribing information. https://www.egetis.com/wp-content/uploads/emcitate-full-prescribing-information.pdf
- Egetis Therapeutics · 2026-03-27. Egetis announces FDA acceptance and Priority Review of NDA for Emcitate (tiratricol) for MCT8 deficiency. https://www.egetis.com/mfn_news/egetis-announces-fda-acceptance-and-priority-review-of-nda-for-emcitate-tiratricol-for-mct8-deficiency/
- European Medicines Agency · 2025-02-12. Emcitate (tiratricol): European Public Assessment Report overview. https://www.ema.europa.eu/en/medicines/human/EPAR/emcitate
- The Lancet Diabetes & Endocrinology · 2019-09. Effectiveness and safety of the tri-iodothyronine analogue Triac in children and adults with MCT8 deficiency: an international, single-arm, open-label, phase 2 trial. https://pubmed.ncbi.nlm.nih.gov/31377265/
- Egetis Therapeutics · 2024-06-19. Egetis announces topline results of the Phase 2 Triac Trial II with Emcitate (tiratricol) for MCT8 deficiency. https://www.egetis.com/mfn_news/egetis-announces-topline-results-of-the-phase-2-triac-trial-ii-with-emcitate-tiratricol-for-mct8-deficiency/
- Egetis Therapeutics · 2025-11-14. Egetis announces positive results from the ReTRIACt study of Emcitate (tiratricol) in MCT8 deficiency. https://www.egetis.com/mfn_news/egetis-announces-positive-results-from-the-retriact-study-of-emcitate-tiratricol-in-mct8-deficiency/
- European Medicines Agency · 2025-02-12. Emcitate (tiratricol): Summary of Product Characteristics. https://www.ema.europa.eu/en/documents/product-information/emcitate-epar-product-information_en.pdf
- ClinicalTrials.gov. Triac Trial II in MCT8 Deficiency Patients. https://clinicaltrials.gov/study/NCT02396459
- ClinicalTrials.gov. Expanded Access Program for Tiratricol in Patients With Monocarboxylate Transporter 8 Deficiency. https://clinicaltrials.gov/study/NCT05911399
- Egetis Therapeutics · 2026-08-21. Egetis Therapeutics half-year report January to June 2026. https://storage.mfn.se/6c82a19d-695a-4901-8a96-566ea896cfa4/q2-2026-report-eng-20aug26c.pdf