Reported Reactions

Drugs › l-Thyroxine

Brand name · Thyroid tablets

NP Thyroid: adverse event reports filed with FDA

753 reports list it as a suspect or interacting product, 2017–2026. Class: l-Thyroxine.

753
reports as suspect product
0% of all reports · about 81 a year
30
reports, 12 months to June 2026
22 in the 12 months before
66.8%
marked serious by the reporter
48.4% across the class
1.5%
record death among outcomes, as reported
11 reports · not verified by FDA

Between March 2017 and June 2026, 753 adverse event reports received by FDA list the brand name NP Thyroid (thyroid tablets) as a suspect or interacting product. Reports that mention it only as a concomitant medication (1,539) are left out of every figure here.

In the 12 months to June 2026, 30 reports listed it, up 36% from 22 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 81 reports a year and 0% of the 20,646,523 reports in the database, and 1.5% of the reports for the l-Thyroxine class. How many people take it is not in the data, so a count is not a rate of occurrence.

The reactions recorded most often are fatigue (30.4%), palpitations (17.7%) and recalled product administered (14.1%). A report can list several reactions, so shares add to more than 100%; 272 different terms appear across these reports. Fatigue is recorded in 30.4% of these reports, a larger share than in the median l-Thyroxine drug (12.5%).

66.8% of the reports are marked serious by the reporter (48.4% across the class); 1.5% record death among the outcomes and 14.2% record hospitalisation, as reported. 86.5% 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

01020Jul 2021: 20Aug 2021: 13Sep 2021: 7Oct 2021: 3Nov 2021: 4Dec 2021: 52022Jan 2022: 5Feb 2022: 1Mar 2022: 0Apr 2022: 8May 2022: 4Jun 2022: 6Jul 2022: 7Aug 2022: 2Sep 2022: 2Oct 2022: 4Nov 2022: 2Dec 2022: 42023Jan 2023: 2Feb 2023: 3Mar 2023: 2Apr 2023: 2May 2023: 3Jun 2023: 2Jul 2023: 0Aug 2023: 3Sep 2023: 3Oct 2023: 2Nov 2023: 2Dec 2023: 02024Jan 2024: 0Feb 2024: 1Mar 2024: 1Apr 2024: 2May 2024: 4Jun 2024: 1Jul 2024: 2Aug 2024: 4Sep 2024: 4Oct 2024: 1Nov 2024: 1Dec 2024: 22025Jan 2025: 3Feb 2025: 1Mar 2025: 0Apr 2025: 1May 2025: 1Jun 2025: 2Jul 2025: 0Aug 2025: 3Sep 2025: 1Oct 2025: 3Nov 2025: 2Dec 2025: 32026Jan 2026: 3Feb 2026: 4Mar 2026: 4Apr 2026: 3May 2026: 3Jun 2026: 1

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

01673332017: 520172018: 1620182019: 5220192020: 33320202021: 21720212022: 4520222023: 2420232024: 2320242025: 2020252026: 182026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of NP Thyroid reports recording the termmedian drug in l-thyroxine

  1. Fatiguetiredness30.4%229
  2. Palpitationsawareness of the heartbeat17.7%133
  3. Heart rate increaseda fast heart rate reading13.3%100
  4. Alopeciahair loss13%98
  5. Weight increasedweight gain12.1%91
  6. Feeling abnormalfeeling odd or not right10.8%81
  7. Dizzinesslight-headedness or unsteadiness9.8%74
  8. Headachehead pain9.6%72
  9. Anxietyanxiety9.4%71
  10. Product odour abnormalthe product smelt odd9.4%71
  11. Dyspnoeashortness of breath8.5%64
  12. Chest painchest pain8.1%61
  13. Drug ineffectivethe medicine did not work as expected8.1%61
  14. Nauseafeeling sick7.7%58
  15. Insomniadifficulty sleeping7.2%54
  16. Depressionlow mood6.8%51
  17. Astheniaweakness or lack of energy6.5%49
  18. Product substitution issuea problem after switching products6.5%49
  19. Malaisegeneral feeling of being unwell5.8%44
  20. Weight decreasedweight loss5.6%42
  21. Blood pressure increaseda raised blood pressure reading5.4%41
  22. Muscular weaknessmuscle weakness5.4%41
  23. Hypertensionhigh blood pressure5.3%40
  24. Arthralgiajoint pain5.2%39
  25. Painpain, site not specified5%38
  26. Product measured potency issue5%38
  27. Hypothyroidismunderactive thyroid4.9%37

Top 30 of 272 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 median share across the 6 drugs in the l-thyroxine class; 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

Death1.5%11
Life-threatening5.7%43
Hospitalisation (initial or prolonged)14.2%107
Disability17.5%132
Congenital anomaly0.7%5
Other serious41.2%310
Not serious33.2%250

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 51,210 reports in the class. 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 20.5%4
2 to 110.1%1
12 to 170%0
18 to 4420.3%153
45 to 6439.8%300
65 to 7413.5%102
75 and over4.9%37
Age not given20.7%156

Patient sex

Female89.9%677
Male5.2%39
Not given4.9%37

Who reported

Physician0.8%6
Pharmacist3.7%28
Other health professional4.6%35
Lawyer0%0
Consumer or non-health professional86.5%651
Not given4.4%33

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 99.7% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Hypothyroidism42756.7%
Autoimmune thyroiditis739.7%
Thyroid disorder283.7%
Thyroidectomy111.5%
Hyperthyroidism70.9%
Thyroid hormones decreased60.8%

The indication field is filled in by the reporter and is often blank; shares are of all 753 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of NP Thyroid reports
Armour Thyroid7910.5%
Synthroid719.4%
Vitamin d618.1%
Levothyroxine587.7%
Vitamin c466.1%
Ergocalciferol456%
Magnesium405.3%
Vitamin B12253.3%
Calcium212.8%
Progesterone212.8%

Other products listed in reports where NP Thyroid is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureNP Thyroidl-ThyroxineAll reports
Reports as suspect product75351,21020,646,523
Share of that pool—1.5%0%
Reports, latest 12 months30—1,332,454
Marked serious66.8%48.4%57.4%
Death recorded among outcomes, per 1,000 reports156291
Hospitalisation recorded, per 1,000 reports142172213
Consumer-filed share86.5%69%45.8%
Top term, share of reportsFatigue 30.4%median 12.5%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."

Other drugs in the l-thyroxine class

DrugName typeReportsLatest 12 monthsMarked serious
Synthroidbrand26,8311,91038.1%
Levothyroxine sodiumgeneric14,3721,01366.1%
Euthyroxbrand3,59613389.6%
Levoxylbrand3,3827027.7%
Tirosintbrand2,27620517%

Ordered by report count for navigation only. 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." A brand and its generic are separate rows because reporters name them separately.

Questions about NP Thyroid reports

How many adverse event reports has FDA received for NP Thyroid?

753 reports list NP Thyroid as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 30 of them arrived in the latest 12 months. Another 1,539 list it only as a concomitant medication.

What reactions are recorded in NP Thyroid reports?

fatigue (30.4%), palpitations (17.7%), recalled product administered (14.1%), heart rate increased (13.3%) and alopecia (13%). 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 NP Thyroid was responsible.

How serious are the reports?

66.8% are marked serious by the reporter. Among the outcomes recorded, 1.5% of reports include death and 14.2% 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 (86.5%), other health professional (4.6%) and not given (4.4%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for NP Thyroid rising?

30 reports in the 12 months to June 2026, up 36% from 22 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 NP Thyroid 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 NP Thyroid?

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 NP Thyroid as a suspect or interacting product; reports listing it only as a concomitant medication (1,539) 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.