Vitamin B-1 100 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Vitamin B-1 100 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.
Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy
Vitamin B-1 100 mg is a dietary supplement by Nature's Bounty with 1 active ingredient. Its ingredients are commonly taken for preventing or treating thiamine deficiency, beriberi, wernicke-korsakoff syndrome (alcohol-related).Based on those ingredients, 3 medications have a known interaction with it, the most serious rated minor. The ingredients most likely to interact are Thiamine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Vitamin B-1 100 mg by Nature's Bounty
Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B-1 100 mg by Nature's Bounty — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Vitamin B-1 100 mg by Nature's Bounty
Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.
What’s inside
Full disclosure
This product contains one active ingredient: thiamine (vitamin B-1), a water-soluble B vitamin your body needs to convert food into energy and support nerve and heart function. The tablet also contains several inactive ingredients (dicalcium phosphate, vegetable cellulose, stearic acid, silica, and vegetable magnesium stearate) that help form and preserve the pill.
Does it work?
Strong evidence
Thiamine is effective for treating thiamine deficiency and Wernicke-Korsakoff syndrome (WKS), a serious condition caused by severe thiamine lack that affects memory and coordination. The evidence is also possibly effective for dysmenorrhea (painful periods).
For mosquito repellent and heart failure, the evidence suggests it's possibly ineffective—so don't rely on it for those uses.
How safe is it?
Well-documented data
Thiamine is generally very safe when taken by mouth in the doses recommended on the label. Allergic reactions—like skin rashes—are rare when you take it orally, though they can happen.
If you're pregnant or breastfeeding, thiamine is actually needed; talk with your doctor or pharmacist about what dose is right for you, since you should use supplements only as they advise.
Meds to double-check
Minor interactions only
If you take trimethoprim (Proloprim), an antibiotic, let your pharmacist know before adding this supplement—it can raise your thiamine levels. Check your exact medications with the tool on this page before you start.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Only minor medication interactions are documented, and safety information is well characterized.
This supplement is a straightforward way to get thiamine if you're deficient or at risk for deficiency, or if you have WKS. If you take trimethoprim or other medications that affect your kidneys or liver, check with us first.
It's a low-interaction product overall, but it's worth a quick conversation with your pharmacist.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jan 25, 2012.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about Vitamin B-1 100 mg, straight from the product label.
| Brand | Nature's Bounty |
|---|---|
| Barcode (UPC) | 074312016707 |
| Net contents | 100 Tablet(s) |
| Market status | On market |
| Date entered into DSLD | Jan 25, 2012 |
| DSLD ID | 4342 |
| Product type | Vitamin |
| Supplement form | Tablet Or Pill |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years) |
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.
Supplement Facts
The label details for Vitamin B-1 100 mg by Nature's Bounty, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Thiamine | 100 mg | 6667% |
Other ingredients: Dicalcium Phosphate, Vegetable Cellulose, Stearic Acid, Silica, Vegetable Magnesium Stearate
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity
VITAMIN SUPPLEMENT
Suggested/Recommended/Usage/Directions
DIRECTIONS: For adults, take one (1) to two (2) tablets daily, preferably with a meal.
Precautions
Keep out of reach of children.
WARNING: If you are pregnant, nursing or taking any medications, consult your doctor before use.
Discontinue use and consult your doctor if any adverse reactions occur.
Do not use if seal under cap is broken or missing.
FDA Disclaimer Statement
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Storage
Store in a cool, dry place.
General Statements
As a B Vitamin, Thiamin (Vitamin B-1) plays a role in energy metabolism and nervous system function.*
Promotes Energy Metabolism*
Thiamin HCI
General
Prod. No. 1670 07D B17590
Brand IP Statement(s)
© 2009 Nature’s Bounty, Inc.
Nutrition Questions or Comments? Call NutraPhone(R) 1-800-433-2990 Mon.- Fri. 9 AM - 7 PM ET
Formulation
No Artificial Color, Flavor or Sweetener, No Preservatives, No Sugar, No Starch, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Yeast, No Fish. Sodium Free.
Seals/Symbols
(recycle) Healthy you Healthy earth
B
LABORATORY TESTED GUARANTEED QUALITY
NATURE'S BOUNTY(R)
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Vitamin B-1 100 mg by Nature's Bounty label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.
View the full label (PDF)The Ingredients in Vitamin B-1 100 mg by Nature's Bounty
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Tablet(s) Dosage formTablet Or Pill Amounts shown are per serving.
Thiamine
Interacts with3 drugs
Thiamine (vitamin B1) is an essential nutrient your body needs to turn food into energy and to keep your nerves and heart healthy. Most people get eno...
Thiamine monograph & interactionsOther (inactive) ingredients: Dicalcium Phosphate, Vegetable Cellulose, Stearic Acid, Silica, Vegetable Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.
Vitamin B-1 100 mg by Nature's Bounty Drug Interactions
HelloPharmacist Interaction Report
Vitamin B-1 100 mg from Nature's Bounty interacts with a small number of medications.
Thiamine, the single active ingredient, can interact with trimethoprim (Proloprim), an antibiotic used to treat certain infections. Trimethoprim may block how your kidneys and liver clear thiamine from your body, which could raise thiamine levels in your blood.
This is a Minor interaction.
Read the full breakdown — every affected drug type, severity by severity
Although we've documented this interaction with trimethoprim, thiamine has been checked against additional medications as well. Altogether, these interactions span 3 individual medications.
If you take any prescription medications—especially antibiotics or drugs that affect kidney or liver function—run them through the medication checker below before you start this supplement.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Vitamin B-1 100 mg?
Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.
Go to the checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Vitamin B-1 100 mg interact with 3 drugs. Click any drug to see the details.
1 of the 1 ingredient in Vitamin B-1 100 mg interact with drugs. Each result below shows which ingredient is responsible. Thiamine
Sulfadiazine, TrimethoprimCoptin
How Sulfadiazine, Trimethoprim interacts with Vitamin B-1 100 mg — through 1 ingredient. Tap an ingredient for the detail:
ThiamineTrimethoprim (proloprim) Minor
Interaction Summary
Trimethoprim might increase blood levels of thiamine.
Read the full Thiamine + Sulfadiazine, Trimethoprim interactionSulfamethoxazole, TrimethoprimBactrim, Bactrim DS, Bactrim IV, Cotrim, Cotrim DS, Cotrimix +9 more
How Sulfamethoxazole, Trimethoprim interacts with Vitamin B-1 100 mg — through 1 ingredient. Tap an ingredient for the detail:
ThiamineTrimethoprim (proloprim) Minor
Interaction Summary
Trimethoprim might increase blood levels of thiamine.
Read the full Thiamine + Sulfamethoxazole, Trimethoprim interactionTrimethoprimProloprim, Trimpex
How Trimethoprim interacts with Vitamin B-1 100 mg — through 1 ingredient. Tap an ingredient for the detail:
ThiamineTrimethoprim (proloprim) Minor
Interaction Summary
Trimethoprim might increase blood levels of thiamine.
Read the full Thiamine + Trimethoprim interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Vitamin B-1 100 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.
Thiamine
Trimethoprim (Proloprim)
Trimethoprim might increase blood levels of thiamine.
In vitro, animal, and clinical research suggest that trimethoprim inhibits intestinal thiamine transporter ThTR-2, hepatic transporter OCT1, and renal transporters OCT2, MATE1, and MATE2, resulting in paradoxically increased thiamine plasma concentrations.
Brand information
Manufacturer and brand details for Vitamin B-1 100 mg, from the product label.
Vitamin B-1 100 mg by Nature's Bounty: Common Questions
Does Vitamin B-1 100 mg by Nature's Bounty interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Is thiamine safe to take if I'm pregnant or breastfeeding?
Will this help with my menstrual cramps?
Can I take this if I take antibiotics?
What's thiamine actually for?
Does this have a lot of fillers?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Vitamin B-1 100 mg is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.
The Full Monographs Behind Vitamin B-1 100 mg’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
Vitamin B-1 100 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
The 7 references behind this product’s interaction data
Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.
Thiamine 7 references
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
- Rogovik, A. L., Vohra, S., and Goldman, R. D. Safety considerations and potential interactions of vitamins: should vitamins be considered drugs? Ann.Pharmacother. 2010;44(2):311-324. PubMed
- Arruti N, Bernedo N, Audicana MT, Villarreal O, Uriel O, Muñoz D. Systemic allergic dermatitis caused by thiamine after iontophoresis. Contact Dermatitis. 2013 Dec;69(6):375-6. PubMed
- Thiamine hydrochloride injection package insert. Lake Zurich, IL: Fresenius Kabi, LLC; September 2019.
- Vora B, Wen A, Yee SW, et al. The Effect of Trimethoprim on Thiamine Absorption: A Transporter-Mediated Drug-Nutrient Interaction. Clin Pharmacol Ther 2023;114(2):381-392.
Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC