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Dietary supplement

Sustained Release Vitamin B1 300 mg Ingredients & Drug Interactions

by NaturesPlus

Sustained Release Vitamin B1 300 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 Sustained Release Vitamin B1 300 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

Sustained Release Vitamin B1 300 mg is a dietary supplement by NaturesPlus 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 Sustained Release Vitamin B1 300 mg by NaturesPlus

Ask about any prescription or over-the-counter medication and we check it for interactions with Sustained Release Vitamin B1 300 mg by NaturesPlus — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Sustained Release Vitamin B1 300 mg by NaturesPlus

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 (also called vitamin B1), at a 300 mg dose in sustained-release form. Thiamine is a B vitamin your body uses to convert food into energy and to support nerve and heart function.

The inactive ingredients—hydroxypropyl methylcellulose, stearic acid, magnesium stearate, rice bran, and pharmaceutical glaze—are fillers and binders that hold the tablet together and help release the thiamine gradually over time.

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

This product doesn't appear to be marketed for a specific use, so we graded Thiamine's overall clinical evidence instead.

Strong

Strong clinical evidence supports Thiamine for:

Why this rating?
  • The label markets general wellness (“Energy support”), not a specific health condition, so there is no single claim to grade against clinical-evidence data.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Thiamine deficiency — rated "Effective" (Natural Medicines).
  • On file: Wernicke-Korsakoff syndrome (WKS) — rated "Effective" (Natural Medicines).
  • On file: Dysmenorrhea — rated "Possibly Effective" (Natural Medicines).

Thiamine is effective for treating thiamine deficiency and Wernicke-Korsakoff syndrome (a serious brain condition caused by severe B1 lack, often linked to heavy alcohol use). It's possibly effective for period pain (dysmenorrhea).

The evidence doesn't support its use as a mosquito repellent or for heart failure, though research in those areas is limited.

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 very well tolerated when taken by mouth at normal doses. Allergic reactions like skin rashes are rare, though they can happen.

Thiamine is needed during pregnancy and breastfeeding; if you're pregnant or nursing and want to use a supplement, talk with your provider first to make sure the dose is right for you. If you receive thiamine by injection rather than by mouth, serious allergic reactions are possible but remain uncommon.

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 (an antibiotic), check with your pharmacist before adding this product—it may raise your thiamine levels slightly. No other medication interactions are documented in our data for this ingredient, but run your complete medication list through the checker on this page to be sure.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Only minor medication interactions are documented, and safety information is well characterized.

This is a straightforward B1 supplement best suited for people with a documented thiamine deficiency or those at risk of one (like people with heavy alcohol use or malabsorption issues). If you take trimethoprim or other antibiotics, check your medications first—a Minor interaction is possible but not urgent.

Chat with your pharmacist before starting if you're pregnant, nursing, or on any regular medications.

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 23, 2025.

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 Sustained Release Vitamin B1 300 mg, straight from the product label.

Brand NaturesPlus
Barcode (UPC) 097467016057
Net contents 90 Tablet(s)
Market status On market
Date entered into DSLD Jan 23, 2025
DSLD ID 320547
Product type Vitamin
Supplement form Tablet Or Pill
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, Adult (18 - 50 Years), No Allergies, Gluten 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 Sustained Release Vitamin B1 300 mg by NaturesPlus, 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
90
UPC/BARCODE
097467016057
IngredientAmount% DV
Thiamine300 mg25000%

Other ingredients: Hydroxypropyl Methylcellulose, Stearic Acid, Magnesium Stearate, Rice Bran, Pharmaceutical Glaze

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.
Formulation

Free from synthetic: Colors, preservatives. Free from milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soy and sesame.

Vegetarian

Gluten Free

In a special base which provides for the gradual release of ingredients over a prolonged period of time. Micro-gel sustained release system

Energy Support

Storage

Keep tightly closed in a cool, dry place.

Precautions

Keep out of reach of children.

FDA Disclaimer Statement

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

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: One tablet daily.

Brand IP Statement(s)

Copyright Natural Organics

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

See for yourself

Sustained Release Vitamin B1 300 mg by NaturesPlus label

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

Sustained Release Vitamin B1 300 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 Sustained Release Vitamin B1 300 mg by NaturesPlus

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 container90 Amounts shown are per serving.

Thiamine

Interacts with
3 drugs
300 mg per serving Form: 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: Hydroxypropyl Methylcellulose, Stearic Acid, Magnesium Stearate, Rice Bran, Pharmaceutical Glaze. These complete the product’s ingredient list but are not active constituents.

Interaction report

Sustained Release Vitamin B1 300 mg by NaturesPlus Drug Interactions

Want to check YOUR meds against Sustained Release Vitamin B1 300 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 Sustained Release Vitamin B1 300 mg interact with 3 drugs. Click any drug to see the details.

1 of the 1 ingredient in Sustained Release Vitamin B1 300 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 Sustained Release Vitamin B1 300 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 Sustained Release Vitamin B1 300 mg, from the product label.

NaturesPlus

See all NaturesPlus products
Name
Natural Organics, Inc. makers of NaturesPlus
Street Address
9500 New Horizons Blvd.
City
Amityville
State
New York
ZipCode
11701
Web Address
natureplus.com
Pharmacist Counseling Corner

Sustained Release Vitamin B1 300 mg by NaturesPlus: Common Questions

Does Sustained Release Vitamin B1 300 mg by NaturesPlus interact with any medications?
Yes. Based on its ingredients, Sustained Release Vitamin B1 300 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?
Sustained Release Vitamin B1 300 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.
Is this B1 supplement safe to take every day?
Yes, thiamine is very well tolerated at normal oral doses when taken daily. Allergic reactions are rare. If you have any unusual symptoms like rash or swelling, stop and call your pharmacist.
Can I take this if I'm pregnant or breastfeeding?
Thiamine is needed during pregnancy and breastfeeding, and it's rated likely safe. But don't guess on the dose—talk with your provider first to confirm the right amount for you.
What does thiamine actually do?
Thiamine (vitamin B1) helps your body turn food into energy and supports your nerves and heart. Your body can't store much of it, so you need it regularly from food or supplements.
Will this help with mosquito repellent?
No—the evidence shows it's possibly ineffective for that purpose, so don't count on it to keep bugs away.
What's the difference between this and regular B1 supplements?
This is a sustained-release formula, meaning it releases gradually in your body over several hours instead of all at once. That allows for steadier levels, though both forms work for correcting a deficiency.

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

Not sure if Sustained Release Vitamin B1 300 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.

Sustained Release Vitamin B1 300 mg label
Go deeper

The Full Monographs Behind Sustained Release Vitamin B1 300 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

Sustained Release Vitamin B1 300 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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