Generic name
Methylene blue: adverse event reports filed with FDA
1,128 reports list it as a suspect or interacting product, 2004–2026. Also reported as Methylene Blue Injection Usp, Methylene Blue Injection.
- 1,128
- reports as suspect product
- 0% of all reports · about 50 a year
- 128
- reports, 12 months to June 2026
- 100 in the 12 months before
- 96.3%
- marked serious by the reporter
- 57.4% across all reports
- 16%
- record death among outcomes, as reported
- 180 reports · not verified by FDA
Between January 2004 and June 2026, 1,128 adverse event reports received by FDA list methylene blue, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (370) are left out of every figure here.
In the 12 months to June 2026, 128 reports listed it, up 28% from 100 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 50 reports a year and 0% 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 serotonin syndrome (42.6%), drug interaction (32.7%) and drug ineffective (21.6%). A report can list several reactions, so shares add to more than 100%; 299 different terms appear across these reports. Serotonin syndrome is recorded in 42.6% of these reports, against 0.1% of all reports in the database.
96.3% of the reports are marked serious by the reporter; 16% record death among the outcomes and 67% record hospitalisation, as reported. 59.8% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (40.5%). 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
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
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Methylene blue reports recording the termall reports in the database
- Serotonin syndrometoo much serotonin activity, with agitation, fever and tremor42.6%480
- Drug interactionan interaction between medicines32.7%369
- Drug ineffectivethe medicine did not work as expected21.6%244
- Hypotensionlow blood pressure15.9%179
- Off label useused for a purpose or in a way not on the label13.3%150
- Toxicity to various agentspoisoning or toxic effect of one or more substances10.9%123
- Overdosea dose above the recommended amount7.9%89
- Encephalopathy6.5%73
- Intentional overdosea deliberate overdose6.5%73
- Toxic encephalopathy6.3%71
- Agitationrestlessness5.9%66
- Alanine aminotransferase increasedraised liver enzyme (ALT)5.3%60
- Amylase increased5.2%59
- Myoglobin urine present5.2%59
- Troponin increased5.2%59
- Confusional stateconfusion5.1%58
- Vasoplegia syndrome5.1%58
- Bradycardiaslow heart rate4.6%52
- Coma4.6%52
- Acute kidney injurysudden loss of kidney function4.5%51
- Lactic acidosisa build-up of lactic acid in the blood4.3%48
- Cardiac arrestthe heart stopped4.1%46
- Mydriasis4%45
- Cardiogenic shockshock from the heart failing to pump3.8%43
- Shockshock, a collapse of the circulation3.8%43
- Metabolic acidosistoo much acid in the body fluids3.5%40
Top 30 of 299 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
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
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 58% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Vasoplegia syndrome | 138 | 12.2% |
| Hypotension | 129 | 11.4% |
| Methaemoglobinaemia | 70 | 6.2% |
| Shock | 55 | 4.9% |
| Toxicity to various agents | 50 | 4.4% |
| Parathyroidectomy | 44 | 3.9% |
The indication field is filled in by the reporter and is often blank; shares are of all 1,128 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Methylene blue reports |
|---|---|---|
| Norepinephrine | 316 | 28% |
| Vasopressin | 257 | 22.8% |
| Epinephrine | 237 | 21% |
| Propofol | 219 | 19.4% |
| Fentanyl | 209 | 18.5% |
| Amlodipine | 144 | 12.8% |
| Insulin | 138 | 12.2% |
| Sevoflurane | 138 | 12.2% |
| Fluoxetine | 108 | 9.6% |
| Phenylephrine | 106 | 9.4% |
Other products listed in reports where Methylene blue 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
| Measure | Methylene blue | All reports |
|---|---|---|
| Reports as suspect product | 1,128 | 20,646,523 |
| Share of that pool | — | 0% |
| Reports, latest 12 months | 128 | 1,332,454 |
| Marked serious | 96.3% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 160 | 91 |
| Hospitalisation recorded, per 1,000 reports | 670 | 213 |
| Consumer-filed share | 3.5% | 45.8% |
| Top term, share of reports | Serotonin syndrome 42.6% | 0.1% |
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 Methylene blue reports
How many adverse event reports has FDA received for Methylene blue?
1,128 reports list Methylene blue as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 128 of them arrived in the latest 12 months. Another 370 list it only as a concomitant medication.
What reactions are recorded in Methylene blue reports?
serotonin syndrome (42.6%), drug interaction (32.7%), drug ineffective (21.6%), hypotension (15.9%) and off label use (13.3%). 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 Methylene blue was responsible.
How serious are the reports?
96.3% are marked serious by the reporter. Among the outcomes recorded, 16% of reports include death and 67% 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?
other health professional (59.8%), physician (26.2%) and pharmacist (5.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Methylene blue rising?
128 reports in the 12 months to June 2026, up 28% from 100 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 Methylene blue 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 Methylene blue?
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 Methylene blue as a suspect or interacting product; reports listing it only as a concomitant medication (370) 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.