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Dietary supplement

Vitamin B-1 100 mg Ingredients & Drug Interactions

by AvPAK

Vitamin B-1 100 mg label
See full label image
Tablet Or Pill Category: Vitamin
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
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

The interaction bottom line Most serious interaction: Minor

Vitamin B-1 100 mg is a dietary supplement by AvPAK 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.

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Check Your Meds Against Vitamin B-1 100 mg by AvPAK

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B-1 100 mg by AvPAK — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin B-1 100 mg by AvPAK

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.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: thiamine (vitamin B-1), 100 mg per tablet. Thiamine is an essential B vitamin your body uses to convert food into energy and to support nerve and heart function.

It's also inactive ingredients like microcrystalline cellulose, calcium phosphate, and magnesium stearate to hold the tablet together.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: promote energy metabolism by supporting sugar metabolism.
  • We looked for evidence on: Thiamine deficiency, Wernicke-Korsakoff syndrome (WKS), Fatigue, Energy production, Carbohydrate metabolism.
  • The strongest evidence on file: Thiamine is rated "Effective" for Thiamine deficiency (Natural Medicines).
  • Also on file: Thiamine is rated "Effective" for Wernicke-Korsakoff syndrome (WKS).
  • Also on file: Thiamine is rated "Insufficient Reliable Evidence To Rate" for Fatigue.

Thiamine is effective for treating thiamine deficiency and Wernicke-Korsakoff syndrome (a serious neurological condition caused by severe thiamine lack). It's also possibly effective for dysmenorrhea (painful periods).

For mosquito repellent and heart failure, the evidence suggests it's likely not effective, though research in those areas isn't conclusive.

The evidence, ingredient by ingredient Thiamine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Thiamine is generally well tolerated when taken by mouth in normal doses. Oral allergic reactions like dermatitis are rare.

Injectable thiamine can rarely trigger anaphylactoid or hypersensitivity reactions, but this supplement is a tablet, not an injection. Thiamine is needed during pregnancy and breastfeeding — the safety data rates it likely safe — but use only at doses your doctor or midwife recommends rather than megadoses.

Side effects, ingredient by ingredient Thiamine

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Thiamine.
  • The most serious interaction on file is rated Minor.
  • For scale: 3 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take trimethoprim (Proloprim) or related antibiotics, double-check with your pharmacist before starting this product — it may raise thiamine levels in your blood. For any other medications, no interactions are documented in our data for the ingredients we could check.

Check your own medication Run your meds through the checker above

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.

Vitamin B-1 100 mg is a good choice if you have or are at risk for thiamine deficiency or Wernicke-Korsakoff syndrome. If you're on trimethoprim (an antibiotic), check with your pharmacist before adding this supplement.

For most people with normal diets, a B-complex or multivitamin covers thiamine needs, so ask your provider if you really need a standalone dose.

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 Aug 23, 2022.

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

At a glance

General information

Key facts about Vitamin B-1 100 mg, straight from the product label.

Brand AvPAK
Barcode (UPC) 5026885115
Net contents 50 Tablet(s)
Market status On market
Date entered into DSLD Aug 23, 2022
DSLD ID 271385
Product type Vitamin
Supplement form Tablet Or Pill
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar Free
From the label
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 AvPAK, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
Servings per container
50
UPC/BARCODE
5026885115
IngredientAmount% DV
Thiamine100 mg6667%

Other ingredients: Microcrystalline Cellulose, Calcium Phosphate, Stearic Acid, Magnesium Stearate, Croscarmellose Sodium, Hydroxypropyl Methylcellulose, Silica

Tap any ingredient to jump to its full detail below.

Label statements
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.
Seals/Symbols

Lab tested potency assay guaranteed release

FDA Statement of Identity

Dietary Supplement

General Statements

50268-851-15 50 Tablets (5 x 10) Unit Dose

Questions/Comments Call 1-855-361-3993

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take one tablet daily, preferably with a meal.

Formulation

May help to create energy in the body by promoting the proper metabolism of sugars.

Preservative & Gluten Free, no sugar, starch, artificial colors, artificial flavors, wheat, yeast, or corn added.

This product is manufactured under strict quality control guidelines, therefore purity and label potency are guaranteed.

Made in USA

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Precautions

Keep out of the reach of children.

Storage

Store in a cool, dry place.

Brand IP Statement(s)

AvPAK A product of AvKare

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Vitamin B-1 100 mg by AvPAK label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Vitamin B-1 100 mg label

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)
What’s inside

The Ingredients in Vitamin B-1 100 mg by AvPAK

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 Servings per container50 Amounts shown are per serving.

Thiamine

Interacts with
3 drugs
100 mg per serving Form: Thiamine Mononitrate, Vitamin B1

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 & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Calcium Phosphate, Stearic Acid, Magnesium Stearate, Croscarmellose Sodium, Hydroxypropyl Methylcellulose, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin B-1 100 mg by AvPAK Drug Interactions

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 checker
3Drugs
3 Minor

Ingredients driving the most interactions

Thiamine 3

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

Each 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.

Thiamine1 drug type · 3 drugs

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.

Likelihood Probable Evidence B
Thiamine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin B-1 100 mg, from the product label.

AvPAK

See all AvPAK products
Name
AvKARE
City
Pulaski
State
TN
ZipCode
38478
Phone Number
1-855-361-3993
Pharmacist Counseling Corner

Vitamin B-1 100 mg by AvPAK: Common Questions

Does Vitamin B-1 100 mg by AvPAK interact with any medications?
Yes. Based on its ingredients, Vitamin B-1 100 mg has a known interaction with 3 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Vitamin B-1 100 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this product really work for mosquito repellent?
No — the evidence we have suggests thiamine is likely not effective as a mosquito repellent, despite what some people claim. If you're looking to prevent mosquito bites, talk to your pharmacist about proven options.
Is it safe to take thiamine if I'm pregnant or breastfeeding?
Yes — thiamine is needed during both pregnancy and breastfeeding, and the safety data rates it likely safe. But use only the dose your doctor or midwife tells you to, not megadoses on your own.
What is thiamine used for in the body?
Thiamine is a B vitamin your body needs to turn food into energy, support your nerves, and keep your heart working properly. If you don't get enough from your diet, you're at risk for deficiency, which can cause serious problems like Wernicke-Korsakoff syndrome.
Can this supplement help with painful periods?
Thiamine is possibly effective for dysmenorrhea (painful menstrual cramps), though the evidence isn't as strong as it is for deficiency. Talk to your doctor about whether it's worth trying for your situation.
Are there any side effects from taking thiamine by mouth?
Oral thiamine is very safe and side effects are rare. Allergic reactions like dermatitis can happen but are uncommon. If you notice a rash or other unusual reaction, stop and tell your pharmacist or doctor.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Vitamin B-1 100 mg is safe with your meds?

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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.

Vitamin B-1 100 mg label
Go deeper

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.

Herb & supplement monograph

Thiamine

Interacts with 3 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 enough from food, but supplements are clear...

Read the full Thiamine monograph →
Sources

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.

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
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. 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
  3. 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
  4. 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
  5. 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
  6. Thiamine hydrochloride injection package insert. Lake Zurich, IL: Fresenius Kabi, LLC; September 2019.
  7. 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.

See these in context on the Thiamine monograph →

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

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