Over-the-counter medication · Vitamin B1 Supplement
thiamine
Also sold as Vitamin B1. This medicine treats thiamine deficiency, also known as beriberi.
Data updated 2026-05-15
- 11,724
- FDA reportsModerately reported
- 1
- Recall record
What the data shows
thiamine (Vitamin B1) is an over-the-counter Vitamin B1 Supplement, reported less often than most tracked drugs (11,724 FDA reports).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
thiamine (Vitamin B1) is an over-the-counter Vitamin B1 Supplement. This medicine treats thiamine deficiency, also known as beriberi.
Thiamine hydrochloride injection is a form of vitamin B1. It is used to treat thiamine deficiency when you need rapid restoration of thiamine.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$2.65/unit
Generic Available
Yes (10 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats thiamine deficiency, also known as beriberi.
Common side effects
Feeling of warmth, Itching, Hives
Key warnings
In rare cases, you may have a severe allergic reaction to thiamine, especially after repeated injections.
The sections below are summarized in plain English from thiamine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Thiamine helps your body turn food into energy. It is important for the health of your nerves, brain, muscles, heart, and digestive system. This injection increases the amount of thiamine in your body.
How to Take It
A healthcare provider will give you this injection into a muscle or vein. For beriberi, you may get 10 to 20 mg three times a day for up to two weeks. To maintain thiamine levels, you may then take a multivitamin containing 5 to 10 mg of thiamine daily for one month. Follow your doctor's instructions carefully.
This is a plain-language summary of thiamine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
If you are pregnant, talk to your doctor before taking this medicine. It is sometimes used for neuritis of pregnancy if vomiting is severe.
This is a plain-language summary of thiamine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
Since a healthcare provider gives this injection, you are not likely to miss a dose. If you have concerns, talk to your doctor.
This is a plain-language summary of thiamine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature, away from light. Only use if the solution is clear and the seal is intact.
Side Effects (from patient reports)
Based on 11,724 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for thiamine, by number of reports
- Feeling sick to your stomach
Feeling sick to your stomach
765 reports
- Difficulty breathing
Difficulty breathing
736 reports
- Loose or watery stools
Loose or watery stools
679 reports
- Discomfort
Discomfort
668 reports
- Feeling tired
Feeling tired
620 reports
- Feeling confused
Feeling confused
617 reports
- Throwing up
Throwing up
546 reports
- Feeling unwell
Feeling unwell
531 reports
- Feeling lightheaded
Feeling lightheaded
510 reports
- Pain in your head
Pain in your head
505 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for thiamine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where thiamine sits
thiamine has more FDA adverse-event reports than 43% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is thiamine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 11,724 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
11,724
Reports Mentioning Death
1,816
15.5% of reports — not proof of cause
Hospitalization Reports
6,403
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | NAUSEA | 765 |
| 4 | DYSPNOEA | 736 |
| 5 | DIARRHOEA | 679 |
| 6 | PAIN | 668 |
| 7 | FATIGUE | 620 |
| 8 | CONFUSIONAL STATE | 617 |
| 9 | VOMITING | 546 |
| 10 | MALAISE | 531 |
| 11 | DIZZINESS | 510 |
| 12 | HEADACHE | 505 |
| 13 | FALL | 498 |
| 14 | CONDITION AGGRAVATED | 497 |
| 15 | ACUTE KIDNEY INJURY | 484 |
| 16 | ASTHENIA | 444 |
| 17 | PNEUMONIA | 432 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
In rare cases, you may have a severe allergic reaction to thiamine, especially after repeated injections. This can cause collapse and death. "Wet" beriberi with heart failure is an emergency and must be treated with slow IV thiamine.
Common Questions
What is thiamine?
How will I receive this medication?
What should I do if I experience side effects?
Can I take this medication if I am allergic to thiamine?
How long will I need to take this medication?
Can I take this medication with other vitamins?
What if I have kidney problems?
Will this medication interact with my other medications?
Can I drive or operate machinery while taking this medication?
How will I know if the medication is working?
What are the common side effects of thiamine?
What drug class is thiamine?
Is thiamine safe during pregnancy?
Has thiamine been recalled?
Active Recalls
Lack of Assurance of Sterility
Fresenius Kabi Compounding, LLC
Related Medications in Vitamin B1 Supplement
Other drugs grouped near thiamine - same-class peers and common alternatives.
ascorbic acid
Vitamin C
This medicine is a Vitamin C supplement.
Compare with thiamine →
biotin
Vitamin B7
Dialyvite with Zinc is a prescription vitamin supplement.
Compare with thiamine →
calcitriol
Rocaltrol
Calcitriol is a form of vitamin D that helps your body absorb and use calcium.
Compare with thiamine →
calcium carbonate
Tums, Caltrate
Calcium carbonate is a medicine that can relieve heartburn and upset stomach.
Compare with thiamine →
cholecalciferol
Vitamin D3
PNV-DHA is a multivitamin with minerals and essential fatty acids.
Compare with thiamine →
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What the FDA Data Shows for thiamine
The FDA label for thiamine (sold under brand names such as Vitamin B1) classifies it as an over-the-counter product in the Vitamin B1 Supplement class. This medicine treats thiamine deficiency, also known as beriberi. Official labeling lists 7 commonly reported side effects, including Feeling of warmth, Itching, Hives.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 11,724 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. NADAC pricing from CMS shows a generic unit cost of $2.65.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: July 8, 2025
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages