Drug & supplement interaction

Thiamine + Metformin, Linagliptin

Metformin, Linagliptin brand name: Jentadueto.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Thiamine and Metformin, Linagliptin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Metformin, Linagliptin states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Thiamine and Metformin, Linagliptin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Metformin, Linagliptin and Thiamine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Thiamine safety at a glance

Thiamine overall Generally safe Thiamine is generally very safe when taken by mouth in normal amounts.
Pregnancy Likely Safe When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Metformin, Linagliptin and Thiamine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Metformin, Linagliptin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Metformin, Linagliptin is filed under 6 classifications — including organic cation transporter 2 (oct2) substrates, antidiabetes drugs, cytochrome p450 3a4 (cyp3a4) inhibitors. Thiamine has documented interactions with 1 drug class — the most serious being trimethoprim (proloprim) (minor) — and none of Metformin, Linagliptin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Thiamine Does Interact With Other Medications

Thiamine has 3 minor known drug interactions in our database — Metformin, Linagliptin isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Thiamine

Covers the 2,830 medications we’ve checked against Thiamine. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Thiamine and Metformin, Linagliptin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 3 of them are worth acting on rather than waiting out — marked below.

  • A severe allergic reaction / Hives / An allergic reaction Worth acting on Additional detail

    Thiamine

    “Orally, thiamine might rarely cause dermatitis and other allergic reactions. Parenterally, thiamine can cause anaphylactoid and hypersensitivity reactions, but this is also rare (”

    Thiamine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    4 sources cited
    1. 15. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
    2. 35585. 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
    3. 105445. Thiamine hydrochloride injection package insert. Lake Zurich, IL: Fresenius Kabi, LLC; September 2019.
    4. 91170. 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

    Metformin, Linagliptin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin, Linagliptin. Read the label on DailyMed ›

  • Itching Additional detail

    Thiamine

    Recorded for Thiamine in the same Natural Medicines adverse-effect record shown under A severe allergic reaction / Hives / An allergic reaction above.

    Metformin, Linagliptin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin, Linagliptin. Read the label on DailyMed ›

Reported for Thiamine but not commonly for Metformin, Linagliptin: bleeding in the gut, shortness of breath, low blood pressure and a skin rash.

Effects for Metformin, Linagliptin come from the ADVERSE REACTIONS section of its FDA label; effects for Thiamine come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Thiamine in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Worth knowing

No Interaction — But Metformin, Linagliptin May Lower Your Thiamine Levels

These two do not interact. The relationship runs the other way: the licensed record lists Metformin, Linagliptin as associated with lower Thiamine levels — rated “Insufficient Evidence”.

Theoretically, metformin might reduce thiamine activity. Thiamine is involved in the entrance of glycolytic pyruvate into the mitochondrial Kreb's cycle. Reducing thiamine activity might lead to increased amounts of pyruvate being converted to lactic acid. This effect might be responsible for some of the cases of lactic acidosis associated with metformin. This theoretical effect is based on preclinical animal research with phenformin, a similar drug that was produced prior to metformin. This has not yet been substantiated in humans or with the use of metformin.

THIAMINE — Insufficient Evidence

See every medication linked to lower Thiamine levels · See the full Metformin, Linagliptin nutrient report

Disclaimer: This checker finds which nutrients might be depleted by prescription or over-the-counter medications. Each nutrient depletion issue is rated based on clinical significance. Use your own professional judgment prior to making clinical decisions.© 2026 Therapeutic Research Center

How to take them

Some Metformin, Linagliptin Products Have a Food Rule — Thiamine Should Not Break It

At least one FDA label for a product containing Metformin, Linagliptin says to take it with food. If you take Thiamine on an empty stomach out of habit, keep them separate — and take Metformin, Linagliptin with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Metformin, Linagliptin products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Individualize the starting dosage of JENTADUETO XR based on the patient's current regimen ( 2.1 ) The maximum recommended dosage is 5 mg linagliptin/2,000 mg metformin HCl once daily ( 2.1 ) Take orally once daily with a meal, with gradual dose escalation to reduce the gastrointestinal effects due to metformin ( 2.1 ) Swallow whole; do not split, crush, dissolve, or che

From the Dosage and Administration section of the FDA label we read for Metformin, Linagliptin — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Metformin, Linagliptin

This page covers Thiamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin, Linagliptin page lists 285 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), St. John's Wort (major), Acai (moderate) and Adrafinil (moderate).

By severity: 3 major · 242 moderate · 40 minor.

From our pharmacist’s overview on the Metformin, Linagliptin page

“Siberian cocklebur is the risk anyone taking metformin and linagliptin (Jentadueto) should understand first, since it has caused severe hypoglycemia in people who consumed it. The wider picture deserves real care too.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Linagliptin interaction page

One more smart check

Taking Thiamine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3 real supplement products containing Thiamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Thiamine. Even though Thiamine itself has no known interaction with Metformin, Linagliptin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Thiamine and Metformin, Linagliptin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Thiamine
Top 25%

#178 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin, Linagliptin
Steady interest

#1,553 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Thiamine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Thiamine and Metformin, Linagliptin records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Thiamine

What is Thiamine?

  • Preventing or treating thiamine deficiency
  • Beriberi
  • Wernicke-Korsakoff syndrome (alcohol-related)
  • Supporting energy and nerve function
  • General B-vitamin supplementation

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 clearly useful for deficiency, certain medical conditions, and people with heavy alcohol use. Talk with your pharmacist or doctor before starting it, especially if you have a chronic illness.

Tablets, capsules, oral liquids, injectable solutions (prescription), part of B-complex and multivitamins

An interaction check asks whether these two react with each other — it does not ask whether Thiamine is a good idea for someone in your situation. Here is what our Thiamine record says about it on its own.

Thiamine: dosing

The right dose of thiamine depends on your age, health, and the reason you are taking it. There is a recommended daily intake for general nutrition, and higher amounts are sometimes used by doctors to treat a deficiency.For supplements, the best approach is to follow the directions on the product label and not exceed them without guidance.

From our Thiamine monograph — the full record covers uses, side effects and every documented interaction.

Read the full Thiamine monograph & all interactions
Keep checking

Other Drugs & Thiamine

Browse every other medication we’ve checked against Thiamine — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
3Minor
2,826No known interaction
Minor

3 interactions

No interaction 2,826 drugs checked — show the list
Evidence & sources

Thiamine References

The 7 references that drive our Thiamine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Thiamine and Metformin, Linagliptin Together: Common Questions

Is it safe to take Thiamine with Metformin, Linagliptin?
We do not list a known interaction between Thiamine and Metformin, Linagliptin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Thiamine and Metformin, Linagliptin have any of the same side effects?
Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Thiamine and Metformin, Linagliptin at the same time of day?
At least one FDA label for a product containing Metformin, Linagliptin says to take it with food. If you take Thiamine on an empty stomach out of habit, keep them separate and take Metformin, Linagliptin with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Metformin, Linagliptin products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Can Metformin, Linagliptin lower my Thiamine levels?
Natural Medicines records Metformin, Linagliptin as a medicine that can deplete Thiamine. That is the opposite direction to an interaction — it is a reason some people are told to take a supplement, not a reason to avoid one. Do not start one on the strength of this page; ask your pharmacist or doctor whether it applies to you.
How was the Thiamine and Metformin, Linagliptin combination checked?
Interactions in our licensed database are recorded against drug classes. Metformin, Linagliptin is filed under 6 classifications, and Thiamine has documented interactions with 1 drug class — none of Metformin, Linagliptin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Thiamine interact with any other medications?
Yes. Thiamine has 3 documented drug interactions in our database — Metformin, Linagliptin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Metformin, Linagliptin interact with any supplements?
Yes. Metformin, Linagliptin has documented interactions with 285 supplements in our database — Thiamine is not one of them. The Metformin, Linagliptin interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Metformin, Linagliptin and Thiamine?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.