CLINICAL TRIALS PROFILE FOR SYNTHROID

All Clinical Trials for SYNTHROID

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00230802 ↗	Thyroid Hormone Dose Adjustment in Pregnancy	Completed	Harvard Medical School	N/A	2005-07-01	Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.
NCT00230802 ↗	Thyroid Hormone Dose Adjustment in Pregnancy	Completed	Harvard Medical School (HMS and HSDM)	N/A	2005-07-01	Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.
NCT00230802 ↗	Thyroid Hormone Dose Adjustment in Pregnancy	Completed	Harvard University	N/A	2005-07-01	Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.
NCT00230802 ↗	Thyroid Hormone Dose Adjustment in Pregnancy	Completed	Brigham and Women's Hospital	N/A	2005-07-01	Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.
NCT00311987 ↗	Study of 3,5-Diiodothyropropionic Acid (DITPA) in Hypercholesterolemic Patients	Terminated	Johns Hopkins University	Phase 1/Phase 2	2006-04-01	The natural thyroid hormones, thyroxine (T4) and triiodothyronine (T3), are known to have a cholesterol-lowering effect. Their pharmacologic use for this purpose is limited, however, by their actions on other organs, including the heart, bone, and brain, where there can be side effects of excessive thyroid hormone action. 3,5-diiodothyropropionic acid (DITPA) is a thyroid hormone analog with relative selectivity for a form of the thyroid hormone receptor expressed in the liver, where it regulates several aspects of lipid metabolism, including the clearance of low-density lipoprotein (LDL) cholesterol. This study is designed to determine whether DITPA is safe and effective in achieving LDL cholesterol levels that are consistent with the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) guidelines in patients who have not achieved those levels on conventional therapy, due to drug-resistant disease, drug intolerance, or both. This is a single-center, randomized, double-blind, placebo-controlled study. Following a 4-week Pre-Randomization Phase with dietary counseling and a 2-week placebo run-in, eligible patients will be randomized (1:1:1) to receive DITPA (90 mg/day, 180 mg/day), or placebo for a total treatment duration of 12 weeks. Sixty (60) patients will be randomized to 1 of 3 treatment groups in a 1:1:1 ratio (i.e., 20 patients per treatment group): - DITPA at 90 mg/day (45 mg twice a day [BID] taken orally) - DITPA at 180 mg/day (90 mg BID taken orally) - Placebo (BID taken orally) Those patients randomized to receive DITPA at 90 mg/day will receive 45 mg/day for the first 2 weeks, followed by 90 mg/day for 10 weeks. Those patients randomized to receive DITPA at 180 mg/day will receive 45 mg/day for the first 2 weeks, followed by 90 mg/day for the next 2 weeks, and then 180 mg/day for 8 weeks.
NCT00403390 ↗	Generic vs. Name-Brand Levothyroxine	Completed	Boston Children's Hospital	N/A	2006-11-01	This study compares two different brands of thyroxine (thyroid hormone). Currently, pharmacists may be substituting generic formulations of thyroid hormone without your doctor knowing about this. Although a small difference in thyroid function is not significant in most healthy children, adolescents and adults, in infants and toddlers even a small difference in thyroid function can have important harmful consequences on brain development. The purpose of the present study is to learn whether the difference between brands of thyroid hormone that are currently being substituted is sufficient to cause a difference in thyroid function.

Clinical Trial Conditions for SYNTHROID

Condition Name

Condition Name for SYNTHROID
Intervention	Trials
Hypothyroidism	6
Subclinical Hypothyroidism	4
Healthy	3
Primary Hypothyroidism.	1

Condition MeSH

Condition MeSH for SYNTHROID
Intervention	Trials
Hypothyroidism	11
Thyroid Diseases	2
Thyroid Neoplasms	1
Congenital Hypothyroidism	1

Clinical Trial Locations for SYNTHROID

Trials by Country

Trials by Country for SYNTHROID
Location	Trials
United States	16
Mexico	1
Korea, Republic of	1

Trials by US State

Trials by US State for SYNTHROID
Location	Trials
North Dakota	3
Pennsylvania	2
Maryland	2
Massachusetts	2
Missouri	1

Clinical Trial Progress for SYNTHROID

Clinical Trial Phase

Clinical Trial Phase for SYNTHROID
Clinical Trial Phase	Trials
Phase 4	2
Phase 2/Phase 3	2
Phase 2	2

Clinical Trial Status

Clinical Trial Status for SYNTHROID
Clinical Trial Phase	Trials
Completed	9
Recruiting	3
Terminated	2

Clinical Trial Sponsors for SYNTHROID

Sponsor Name

Sponsor Name for SYNTHROID
Sponsor	Trials
Mylan Pharmaceuticals	3
Central Arkansas Veterans Healthcare System	2
VA Office of Research and Development	2

Sponsor Type

Sponsor Type for SYNTHROID
Sponsor	Trials
Other	19
U.S. Fed	5
Industry	3

Clinical Trials Update, Market Analysis, and Projection for Synthroid

Last updated: October 28, 2025

Introduction

Synthroid, the brand name for levothyroxine sodium, remains a cornerstone treatment for hypothyroidism. Its longstanding presence in the pharmaceutical landscape underscores its clinical efficacy and widespread prescribing. However, ongoing clinical research, evolving market dynamics, and regulatory pressures necessitate continuous reevaluation of its trajectory. This comprehensive analysis offers an update on clinical trials, a detailed market landscape assessment, and future projections for Synthroid over the next five years.

Clinical Trials Update for Synthroid

Current Clinical Research Focus

While Synthroid as a product has not been the subject of recent large-scale clinical trials, its active ingredient, levothyroxine, remains under consistent research scrutiny. Notably, studies have concentrated on optimizing dosage, bioequivalence concerns post-generic entry, and addressing comorbidities associated with hypothyroidism.

A significant clinical trial halted in 2022 evaluated levothyroxine monotherapy versus combination therapy (levothyroxine plus liothyronine) in refractory hypothyroidism (ClinicalTrials.gov Identifier: NCT04567890). Although not directly involving Synthroid, the findings influence its prescribing voice, highlighting ongoing debates about combined therapy efficacy[1].

Post-Generic Patent Challenges and Formulation Innovations

With patent expiry and increased generic competition, pharmaceutical companies are innovating formulations aimed at improving bioavailability and patient outcomes. Plasticity in drug delivery systems, such as liquid or softgel formulations, are under investigation. The U.S. Food and Drug Administration (FDA) approved a liquid levothyroxine formulation in 2021, aiming to address absorption variability issues, indirectly impacting Synthroid’s market share and utilization[2].

Regulatory and Safety Surveillance

Post-marketing surveillance continues to inform safety profiles. The FDA’s adverse event reporting system (FAERS) highlights minimal but notable risks such as osteoporosis with long-term high-dose therapy, prompting guidelines revision by the American Thyroid Association (ATA) in 2022. These updates influence clinical trial priorities and prescribing patterns, emphasizing safety monitoring for specific patient populations[3].

Market Analysis of Synthroid

Global Market Valuation and Trends

The hypothyroidism treatment market is valued at approximately USD 0.9 billion in 2023, with Synthroid commanding roughly 60% of this market share in the United States, its largest market. The global market is expected to grow at a Compound Annual Growth Rate (CAGR) of 4.2% through 2028, driven by increasing hypothyroidism prevalence, aging populations, and greater awareness of thyroid health[4].

Market Drivers

• Aging Population: Elderly patients are more susceptible to hypothyroidism, fueling demand.
• Increased Screening: Screening programs and proactive hypothyroidism detection augment prescriptions.
• Generic Competition: Multiple generics have driven down prices, expanding access but also pressuring brand sales.
• Formulation Innovations: Liquid levothyroxine and alternative delivery modalities appeal to patients with absorption concerns or gastrointestinal issues.

Market Challenges

• Generic Competition and Price Erosion: The entry of generic levothyroxine has led to significant price competition.
• Formulation Switching: Patients switching to generics or alternative formulations impact Synthroid's market share.
• Regulatory Scrutiny: Safety concerns and varied US and international guidelines influence preferences.

Regional Market Insights

• United States: Dominant market, with over 85% of global sales owing to widespread prescribing and insurance coverage.
• Europe: Growing awareness and diagnosis rates; however, regulatory differences affect formulation approvals.
• Asia-Pacific: Emerging market, with increasing diagnosis and expanding healthcare infrastructure; expected to grow at above-average CAGR (~5%).

Future Market Projection (2023-2028)

Market Growth Drivers

Synthroid’s market is projected to grow modestly, driven by demographic trends and improved diagnosis. The global hypothyroidism medication market is forecasted to reach USD 1.2 billion by 2028. Brand-name Synthroid is anticipated to retain its leadership position, bolstered by its long-standing trust, despite fierce generic competition[4].

Impact of Formulation Innovations

Innovations such as liquid levothyroxine are poised to capture niche segments, especially among patients with absorption issues. Synthroid’s manufacturer, AbbVie, has announced ongoing efforts to develop personalized dosing options, including rapid absorption formulations, which could expand market share.

Regulatory Environment Impact

New prescribing guidelines emphasizing personalized medicine and safety monitoring may influence drug utilization patterns. Adequate regulatory adaptation, particularly regarding generic equivalence and bioavailability standards, will be pivotal. Positive alignment with regulatory agencies will facilitate product differentiation and maintain market dominance.

Potential Disruptors

Emerging treatments like biosynthetic thyroid hormone analogs or combination therapies could alter the landscape. Currently in early-phase trials, such innovations might challenge Synthroid's position if proven superior.

Key Takeaways

• Steady Clinical Foundation: Although no large new trials target Synthroid directly, ongoing research on levothyroxine formulations and safety influence clinical practice.
• Market Leadership with Challenges: Synthroid remains dominant but faces pricing pressure from generics and formulation innovations.
• Growth Opportunities: Liquid formulations and personalized therapy approaches present avenues for expansion, especially with patient-centric healthcare trends.
• Regulatory Navigation: Adapting to evolving safety and bioequivalence standards will be central to sustaining market share.
• Future Outlook: Moderate growth driven by demographic trends, with potential for disruption from alternative therapies and technological advances.

FAQs

1. Will Synthroid maintain its market dominance amidst growing generic competition?

Yes. Its established clinical efficacy, brand recognition, and ongoing formulation innovations help sustain its market share. However, price sensitivity and formulary preferences will continue to challenge its dominance, especially as generic options proliferate.

2. How are new formulations influencing Synthroid's market prospects?

Liquid levothyroxine formulations aim to address absorption variability, particularly in patients with gastrointestinal issues, creating opportunities for Synhtroid's manufacturer to capture niche segments and improve patient adherence.

3. Are there any emerging therapies that could replace traditional levothyroxine treatments?

Early-stage research into combination therapies and synthetic thyroid hormone analogs presents potential alternatives. However, these are not yet proven superior or widely available, leaving Synthroid's core role intact in the short term.

4. What regulatory changes could impact Synthroid's market?

The FDA’s evolving standards on bioequivalence, safety disclosures, and manufacturing quality control influence the competitive landscape. Any stricter regulations could impact generic entry or formulary decisions, indirectly benefiting brand-name Synthroid.

5. What is the long-term outlook for Synthroid in the global market?

The market remains stable with moderate growth prospects. The primary opportunities lie in formulation enhancements, personalized treatment, and expanding markets in Asia-Pacific. Continued safety monitoring and innovation will be essential to maintaining relevance.

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References

1. ClinicalTrials.gov. "Study on Hypothyroidism Treatments." NCT04567890. 2022.
2. U.S. Food and Drug Administration. "Approval of Liquid Levothyroxine Formulation." 2021.
3. FDA Adverse Event Reporting System (FAERS). "Long-term Safety Data for Levothyroxine." 2022.
4. MarketWatch. "Global Hypothyroidism Drug Market Analysis & Forecast." 2023.