Levothyroxine sodium adverse event reports that FDA received

Name: Reaction terms in FDA adverse event reports that name Levothyroxine sodium
Creator: Reported Reactions
License: https://creativecommons.org/publicdomain/zero/1.0/

Name type: Generic name
Class: l-Thyroxine
Also reported as: Levothyroxine Sodium Tablets Usp, Levothyroxine Na, Levothyroxine Sodium Tablets

What a report is

A report is not proof that the drug was the cause of the event.

FDA says:

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview, section "Responsible use of the data". The site read the page on 2 Oct 2026. The data have the reports that FDA received through 30 Jun 2026.

FDA also says:

There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.
Source: openFDA, Response of the drug event API (meta.disclaimer). The site read the page on 2 Oct 2026.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

Reports on file

From January 2004 to June 2026, FDA received 14,372 adverse event reports that name Levothyroxine sodium. In these reports the drug is a suspect or interacting product.

In the same period, 86,649 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 1,013 reports in the 12 months to June 2026 and 1,395 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

The number of people who use the product is not in the data. A count is not a rate. A count of reports is not a count of events or of patients, because one event can have more than one report.

There are many instances of duplicative reports and some reports do not contain all the necessary information.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Levothyroxine sodium is suspect or interacting. FDA says:

Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Data version

openFDA FAERS release of 1 Oct 2026. Reports received through 30 Jun 2026.

Since the last update

FDA says:

Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The information in these reports cannot be used to estimate the incidence (occurrence rates) of the events reported.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

No update is on record for this page. The record starts when FDA adds the reports of July to September 2026.

In April to June 2026, FDA received 248 reports that name Levothyroxine sodium.
In January to March 2026, FDA received 205.
In April to June 2025, FDA received 225.

April to June 2026 is the latest closed quarter in the data. A closed quarter is a quarter for which the FDA files have most of the reports.

All updates Feed of updates (RSS)

Reaction lookup

These are the reaction terms that the reports record, with the number of reports for each term. Type a term or a plain word to find its count.

What this list leaves out

The table lists the 1,113 reaction terms that 5 or more reports record. A term with fewer than 5 reports is not in the table.

The site keeps reaction terms for 14,222 of the 14,372 reports (99%).

The reports of the other years are not in the counts.

So a count in the table can be lower than the count of FDA.

Find a reaction term

The table shows the first 50 of 1,113 terms.

Reaction terms in the reports that name Levothyroxine sodium, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 14,372 reports
Fatiguetiredness	1,712	11.9%
Headachehead pain	1,454	10.1%
Painpain, site not specified	1,430	9.9%
Dyspnoeashortness of breath	1,420	9.9%
Drug ineffectivethe medicine did not work as expected	1,368	9.5%
Nauseafeeling sick	1,046	7.3%
Palpitationsawareness of the heartbeat	1,016	7.1%
Malaisegeneral feeling of being unwell	1,013	7%
Cognitive disorderproblems with thinking or memory	989	6.9%
Falla fall	916	6.4%
Dizzinesslight-headedness or unsteadiness	899	6.3%
Anxiety	877	6.1%
Off label useused for a purpose or in a way not on the label	860	6%
Constipation	850	5.9%
Alopeciahair loss	808	5.6%
Vomitingbeing sick	805	5.6%
Diarrhoealoose or frequent stools	801	5.6%
Hypotensionlow blood pressure	770	5.4%
Insomniadifficulty sleeping	762	5.3%
Asthma	761	5.3%
Pyrexiafever	757	5.3%
Drug interactionan interaction between medicines	734	5.1%
Feeling abnormalfeeling odd or not right	726	5.1%
Arthralgiajoint pain	721	5%
Hypothyroidismunderactive thyroid	709	4.9%
Abdominal discomfortstomach discomfort	687	4.8%
Toxicity to various agentspoisoning or toxic effect of one or more substances	656	4.6%
Pruritusitching	652	4.5%
Astheniaweakness or lack of energy	626	4.4%
Abdominal pain upperupper stomach pain	621	4.3%
Hypertensionhigh blood pressure	616	4.3%
Mobility decreasedreduced ability to move about	599	4.2%
Balance disorderproblems with balance	586	4.1%
Rashskin rash	586	4.1%
Orthostatic hypotension	578	4%
Muscular weaknessmuscle weakness	572	4%
Condition aggravatedthe condition being treated got worse	564	3.9%
Tachycardiafast heart rate	552	3.8%
Chest pain	547	3.8%
Sedationdrowsiness	536	3.7%
Gastrooesophageal reflux diseaseacid reflux	532	3.7%
Hyperhidrosisexcessive sweating	531	3.7%
Depressed level of consciousness	523	3.6%
Heart rate increaseda fast heart rate reading	503	3.5%
Tinnitusringing in the ears	502	3.5%
Wheezing	498	3.5%
Migraine	495	3.4%
Loss of personal independence in daily activities	492	3.4%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	490	3.4%
Peripheral swellingswelling of the arms or legs	478	3.3%

Download all 1,113 terms of Levothyroxine sodium (CSV)

The counts add to more than 14,372 reports, because one report can record more than one term. FDA says:

No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The CSV file has the same rows and the same limits. Its last row is a note that says so.

MedDRA term

The person who codes a report selects the preferred term that agrees best with the description of the reporter. The words under a term are the plain meaning that this site gives.

Not the label

The FDA-approved label of a product lists its adverse reactions. See the official pages at the end of this page.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Levothyroxine with a page, in the order generic names, brand names, names as reported
Name	Name type	Reports
Levothyroxine	Generic name	15,937
Levothyroxine sodium (this page)	Generic name	14,372
Euthyrox	Brand name	3,499
Levoxyl	Brand name	3,382
Synthroid	Brand name	26,831
Tirosint	Brand name	2,276

Sum of the separately reported names: 66,297. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Outcomes by year

The table gives the outcomes that the reporters gave, in the terms of FDA.

Outcomes in the reports that name Levothyroxine sodium, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA file	Reports	Serious	Death	Life-threatening	Hospitalization (initial or prolonged)	Disability or Permanent Damage	Congenital Anomaly/Birth Defect	Other Serious (Important Medical Events)	Not serious
2004	151	98	12	7	69	3	1	31	53
2005	198	141	9	9	100	5	3	49	57
2006	217	151	18	5	73	6	4	64	66
2007	217	165	11	15	95	8	0	73	52
2008	256	187	24	11	76	12	1	102	69
2009	368	277	44	20	125	8	2	124	91
2010	438	314	38	22	132	16	4	155	124
2011	549	420	81	20	150	17	4	238	129
2012	553	458	47	27	180	13	9	285	95
2013	474	162	23	7	54	3	2	111	312
2014	471	136	14	5	40	2	8	87	335
2015	360	121	22	3	50	2	1	70	239
2016	354	119	5	11	54	9	0	77	235
2017	627	351	70	6	69	8	1	265	276
2018	691	322	51	14	121	8	6	229	369
2019	584	272	52	13	104	6	3	223	312
2020	651	432	51	32	222	17	9	347	219
2021	1,039	746	75	42	434	9	4	632	293
2022	1,438	1,124	124	94	630	25	12	927	314
2023	1,344	1,054	65	147	465	91	27	890	290
2024	1,040	858	78	180	390	40	14	734	182
2025	1,650	996	109	222	515	104	24	898	654
2026	702	597	91	129	302	89	28	550	105

An outcome in a report is not proof that the drug was the cause. The reporter gives the outcome, and FDA does not verify it. FDA says:

The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The six headings with the names of FDA are the outcome terms of FDA. A report can have more than one outcome. The columns Serious and Not serious are the two values of the openFDA field serious. For the value serious, openFDA gives this description:

The adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition
Source: openFDA, Drug adverse event fields (YAML reference). The site read the page on 2 Oct 2026.

The year is the year of the openFDA file that holds the latest version of the report. It is not always the year in which FDA first received the report. The chart of the next section uses the year of first receipt. The latest year is not complete.

Reports by year and month

Reports that name Levothyroxine sodium, by the year in which FDA received them

The column of 2026 has an outline, because the year is not complete. It has the reports that FDA received through June 2026 only.

Show the figures of the chart as a table

Reports that name Levothyroxine sodium, by the year in which FDA received them
Year	Reports
2004	98
2005	151
2006	170
2007	197
2008	404
2009	318
2010	439
2011	527
2012	677
2013	475
2014	486
2015	379
2016	369
2017	672
2018	760
2019	652
2020	761
2021	1,248
2022	1,405
2023	1,289
2024	1,005
2025	1,437
2026	453

Reports that name Levothyroxine sodium, by month, five years to June 2026

FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Why a count moves

A count moves for many reasons. The guide gives FDA's words about them.

Patients and reporters

Age of the patient in the reports that name Levothyroxine sodium
Age	Reports	Share
Under 2	95	0.7%
2 to 11	84	0.6%
12 to 17	111	0.8%
18 to 44	1,326	9.2%
45 to 64	3,178	22.1%
65 to 74	1,770	12.3%
75 and over	2,419	16.8%
Age not given	5,389	37.5%

Sex of the patient in the reports that name Levothyroxine sodium
Sex	Reports	Share
Female	9,810	68.3%
Male	2,404	16.7%
Unknown or not given	2,158	15%

Type of reporter in the reports that name Levothyroxine sodium
Reporter	Reports	Share
Physician	2,855	19.9%
Pharmacist	739	5.1%
Other health professional	3,812	26.5%
Lawyer	12	0.1%
Consumer or non-health professional	6,052	42.1%
Not given	902	6.3%

Age and sex are as the report gives them. The reporter is the primary source in the report. 50.5% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Levothyroxine sodium record
Indication as recorded (MedDRA)	Reports	Share
Hypothyroidism	3,273	22.8%
Thyroid disorder	889	6.2%
Autoimmune thyroiditis	286	2%
Thyroidectomy	159	1.1%
Thyroid hormone replacement therapy	65	0.5%
Ill-defined disorder	62	0.4%

The reporter fills in the indication, and the field is often empty. Each share is of all 14,372 reports.

Drugs in the same reports

Other drugs that the reports of Levothyroxine sodium name, in any role, in order of name
Drug	Reports that name the two
Acetaminophen	1,726
Albuterol	1,028
Amlodipine	865
Amlodipine besylate	779
Aspirin	1,300
Ergocalciferol	979
Furosemide	1,415
Hydrochlorothiazide	812
Omeprazole	1,440
Prednisone	1,024

The table has the 10 drug names that these reports name most. Two names in one report says only that the report recorded the two. It says nothing about the part of a product in the event.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Pages near this one

Levothyroxine same ingredient
Euthyrox same ingredient
Levoxyl same ingredient
Synthroid same ingredient
Tirosint same ingredient
NP Thyroid same class
Levothyroxin next in the A to Z list
Levulan Kerastick next in the A to Z list
Levothyrox next in the A to Z list
Lexapro next in the A to Z list
Levothroid next in the A to Z list
Lexiscan(r) (regadenoson) next in the A to Z list

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

DailyMed labels for Levothyroxine sodiumThe labels (prescribing information) that have this name, at the National Library of Medicine.
MedWatch Online Voluntary Reporting FormThe online form of FDA for a voluntary report.
MedWatch: The FDA Safety Information and Adverse Event Reporting ProgramThe page of the FDA program that receives reports about drugs and devices.
FDA Adverse Event Monitoring System (AEMS) Public DashboardThe public dashboard of FDA for adverse event reports on drugs and biologics.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Reported Reactions. Levothyroxine sodium: adverse event reports that FDA received. https://reportedreactions.com/drug/levothyroxine-sodium/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of 1 Oct 2026. Reports received through 30 Jun 2026.

Where the data come from

The counts come from the openFDA Drug Adverse Event (FAERS) bulk files, release of 1 Oct 2026. The files have the reports that FDA received through 30 Jun 2026. A drug name is the name on the report. The site matches it to a brand name or a generic name of the National Drug Code Directory of 2 Oct 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Levothyroxine sodium as a suspect or interacting product. The 86,649 reports that name it only as a concomitant medicine are not in the count. The site does not publish a report narrative, a lot number, a detail of a patient or the identity of a reporter. The record of FDA is the authority. See how the site counts reports, the data sources and the corrections page.

Questions

Do these reports show that Levothyroxine sodium was responsible for the reactions?

No. FDA says:

For any given report, there is no certainty that a suspected drug caused the event.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

A reaction can relate to the condition that the drug treats, to other medicines, or to something else.

Is this the list of reactions on the label of Levothyroxine sodium?

No. It is a count of what people reported to FDA: 14,372 reports from January 2004 to June 2026. The FDA-approved label of a product lists its adverse reactions. The official pages at the end of this page link to the labels.

Who sent these reports?

Consumer or non-health professional (42.1%), other health professional (26.5%) and physician (19.9%). These are the types of reporter for the reports that name this drug.

If a manufacturer receives an adverse event report, it is normally required to send the report to FDA.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

How does a person report an adverse event?

FDA runs MedWatch, a program that takes voluntary reports from health professionals, patients and consumers. The guide on how to report has the links.

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