Reported Reactions

Drugs

Product name as reported

Novothyrox: adverse event reports filed with FDA

10,454 reports list it as a suspect or interacting product, 2013–2018.

10,454
reports as suspect product
0.1% of all reports · about 804 a year
0
reports, 12 months to June 2026
0 in the 12 months before
99.6%
marked serious by the reporter
57.4% across all reports
1%
record death among outcomes, as reported
108 reports · not verified by FDA

Between July 2013 and September 2018, 10,454 adverse event reports received by FDA list the product name "Novothyrox" as reporters wrote it as a suspect or interacting product. Reports that mention it only as a concomitant medication (0) are left out of every figure here.

In the 12 months to June 2026, 0 reports listed it, and none in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 804 reports a year and 0.1% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

The MedDRA terms listed most often are fatigue (49.7%), headache (29%) and insomnia (24.1%). A report can list several reactions, so shares add to more than 100%; 1,236 different terms appear across these reports. Fatigue is recorded in 49.7% of these reports, against 3.7% of all reports in the database.

99.6% of the reports are marked serious by the reporter; 1% record death among the outcomes and 10.6% record hospitalisation, as reported. 75.5% of the reports came from consumers, and the largest patient age group is 45 to 64 (39.8%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

No report listing Novothyrox was received in the five years to June 2026; the latest was received in September 2018.

By year received

03,1536,3062013: 120132014: 120142015: 16120152016: 63720162017: 6,30620172018: 3,3482018

Reactions recorded in the reports

share of Novothyrox reports recording the termall reports in the database

  1. Fatiguetiredness49.7%5,197
  2. Headachehead pain29%3,028
  3. Insomniadifficulty sleeping24.1%2,518
  4. Vertigoa spinning sensation19.6%2,045
  5. Muscle spasmsmuscle cramps18.9%1,977
  6. Weight increasedweight gain16.3%1,707
  7. Astheniaweakness or lack of energy15.3%1,601
  8. Myalgiamuscle pain14.7%1,540
  9. Dizzinesslight-headedness or unsteadiness13.6%1,418
  10. Alopeciahair loss13.5%1,411
  11. Nauseafeeling sick13.3%1,390
  12. Arthralgiajoint pain13.2%1,383
  13. Depressionlow mood12.7%1,331
  14. Palpitationsawareness of the heartbeat11.9%1,241
  15. Irritabilityirritability11.2%1,172
  16. Diarrhoealoose or frequent stools9.8%1,022
  17. Diffuse alopecia9.5%996
  18. Disturbance in attentiondifficulty concentrating8.4%879
  19. Blood thyroid stimulating hormone decreased8.4%876
  20. Anxietyanxiety7.8%820
  21. Blood thyroid stimulating hormone normal7.3%767
  22. Hot flusha hot flush7.3%760
  23. Hyperhidrosisexcessive sweating7.1%739
  24. Amnesiamemory loss7%731
  25. Malaisegeneral feeling of being unwell7%731
  26. Hyperthyroidismoveractive thyroid6.7%704
  27. Sleep disordera sleep problem6.5%683
  28. Dyspnoeashortness of breath6.5%677
  29. Tachycardiafast heart rate6.4%674

Top 30 of 1,236 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Death1%108
Life-threatening0.4%43
Hospitalisation (initial or prolonged)10.6%1,111
Disability2.5%262
Congenital anomaly0.4%43
Other serious87.5%9,151
Not serious0.4%41

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 20.1%9
2 to 110.2%25
12 to 170.3%35
18 to 4419.7%2,059
45 to 6439.8%4,160
65 to 7414.2%1,481
75 and over5.4%560
Age not given20.3%2,125

Patient sex

Female82%8,573
Male8.2%861
Not given9.8%1,020

Who reported

Physician2.4%246
Pharmacist0.9%91
Other health professional3.7%390
Lawyer8.9%932
Consumer or non-health professional75.5%7,894
Not given8.6%901

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 0.5% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Hypothyroidism2,89227.7%
Thyroidectomy1,71316.4%
Autoimmune thyroiditis9038.6%
Post procedural hypothyroidism5114.9%
Thyroid disorder3623.5%
Basedow's disease1251.2%

The indication field is filled in by the reporter and is often blank; shares are of all 10,454 reports.

In context

MeasureNovothyroxAll reports
Reports as suspect product10,45420,646,523
Share of that pool—0.1%
Reports, latest 12 months01,332,454
Marked serious99.6%57.4%
Death recorded among outcomes, per 1,000 reports1091
Hospitalisation recorded, per 1,000 reports106213
Consumer-filed share75.5%45.8%
Top term, share of reportsFatigue 49.7%3.7%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Questions about Novothyrox reports

How many adverse event reports has FDA received for Novothyrox?

10,454 reports list Novothyrox as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 0 of them arrived in the latest 12 months. Another 0 list it only as a concomitant medication.

What reactions are recorded in Novothyrox reports?

fatigue (49.7%), headache (29%), insomnia (24.1%), vertigo (19.6%) and muscle spasms (18.9%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Novothyrox was responsible.

How serious are the reports?

99.6% are marked serious by the reporter. Among the outcomes recorded, 1% of reports include death and 10.6% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

consumer or non-health professional (75.5%), lawyer (8.9%) and not given (8.6%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Novothyrox rising?

0 reports in the 12 months to June 2026, and none in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Novothyrox was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Novothyrox?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Novothyrox as a suspect or interacting product; reports listing it only as a concomitant medication (0) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.