Thiamine + Bromocriptine
Bromocriptine brand name: Parlodel.
We found no known interaction between Thiamine and Bromocriptine 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 Bromocriptine 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.
Thiamine and Bromocriptine
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 Bromocriptine 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
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.
Why No Interaction Is Listed for Bromocriptine
Interactions in our licensed database are recorded against drug classes, not just single drug names. Bromocriptine is filed under 4 classifications — including ergot derivatives, dopamine agonists, cytochrome p450 3a4 (cyp3a4) substrates. Thiamine has documented interactions with 1 drug class — the most serious being trimethoprim (proloprim) (minor) — and none of Bromocriptine’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.
Thiamine Does Interact With Other Medications
Thiamine has 3 minor known drug interactions in our database — Bromocriptine isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Thiamine
We haven’t checked that one against Thiamine yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Thiamine. Pick one to open its full report.
Thiamine in Pregnancy & Breastfeeding
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
Some Bromocriptine Products Have a Food Rule — Thiamine Should Not Break It
At least one FDA label for a product containing Bromocriptine says to take it with food. If you take Thiamine on an empty stomach out of habit, keep them separate — and take Bromocriptine 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 Bromocriptine 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 Taken within two hours after waking in the morning with food ( 2.1 ) Initial dose is one tablet (0.8 mg) daily increased weekly by one tablet until maximal tolerated daily dose of 1.6 to 4.8 mg is achieved.
From the Dosage and Administration section of the FDA label we read for Bromocriptine — 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.
What Bromocriptine Is Prescribed For, and What Thiamine Has Been Studied For
These two come up together because they touch the same health topic — not because they do the same job. Bromocriptine is a prescription medicine with approved uses on its FDA label. Thiamine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.
Bromocriptine is prescribed for: Bromocriptine mesylate tablets and capsules (sold as Parlodel and generics) treat conditions caused by too much prolactin in the blood — including missed periods, unwanted breast milk production, infertility, and hypogonadism (low sex-hormone function). They are also used for prolactin-secreting pituitary tumors (adenomas), acromegaly (excess growth hormone), and the signs and symptoms of Parkinson's disease, often alongside levodopa. Cycloset — a specific bromocriptine tablet formulation — is separately approved as an add-on to diet and exercise to improve blood sugar control in adults with type 2 diabetes. Cycloset should not be used for type 1 diabetes or diabetic ketoacidosis.
Thiamine has been studied for:
-
Diabetes studied, not established Thiamine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows
Thiamine for diabetes
It is unclear if oral thiamine is beneficial for type 2 diabetes or gestational diabetes.
Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Bromocriptine on your own; if you are taking Thiamine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.
See Every Supplement That Interacts With Bromocriptine
This page covers Thiamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Bromocriptine page lists 143 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).
By severity: 3 major · 99 moderate · 41 minor.
From our pharmacist’s overview on the Bromocriptine page
“Grapefruit is the supplement-aisle item I would flag first for anyone taking bromocriptine (Parlodel). It blocks CYP3A4, the enzyme that clears bromocriptine, so drug levels can climb and side effects with them.”
Reviewed by 2 · Jul 18, 2026
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 Bromocriptine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Thiamine and Bromocriptine 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.
#184 of 1,452 supplements looked up here in the last 7 days
#498 of 2,830 medications looked up here in the last 7 days
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 20, 2026. The Thiamine and Bromocriptine 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.
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.
About Bromocriptine
What Is Bromocriptine Used For?
Brand name: Parlodel
Bromocriptine mesylate tablets and capsules (sold as Parlodel and generics) treat conditions caused by too much prolactin in the blood — including missed periods, unwanted breast milk production, infertility, and hypogonadism (low sex-hormone function). They are also used for prolactin-secreting pituitary tumors (adenomas), acromegaly (excess growth hormone), and the signs and symptoms of Parkinson's disease, often alongside levodopa.
Cycloset — a specific bromocriptine tablet formulation — is separately approved as an add-on to diet and exercise to improve blood sugar control in adults with type 2 diabetes. Cycloset should not be used for type 1 diabetes or diabetic ketoacidosis.
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.
No drugs match “”.
3 interactions
No interaction 2,826 drugs checked — show the list
We also checked Thiamine against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Abemaciclib ›
- Sertraline ›
- Ivermectin ›
- Testosterone ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Methamphetamine ›
- Tirzepatide ›
- Docusate ›
- Ibuprofen ›
- Tadalafil ›
- Warfarin Sodium ›
- Sumatriptan ›
- Valacyclovir ›
- Hydroxyurea ›
- Isotretinoin ›
- Prednisone ›
- Semaglutide ›
- Metformin ›
- Lisdexamfetamine ›
- Propranolol ›
- Amitriptyline ›
- Amlodipine Besylate ›
- Methotrexate ›
- Amphetamine ›
- Amoxicillin ›
- Lisinopril ›
- Bupropion ›
- Fluoxetine ›
- Bendamustine ›
- Doxycycline ›
- Pregabalin ›
- Lamotrigine ›
- Acyclovir ›
- Azithromycin ›
- Gabapentin ›
- Levothyroxine, Liothyronine ›
- Dextroamphetamine ›
- Naproxen ›
- Quetiapine ›
- Clonazepam ›
- Omeprazole ›
- Buspirone ›
- Duloxetine ›
- Letrozole ›
- Acetaminophen, Codeine ›
- Citalopram ›
- Methylene Blue ›
Showing the 60 most looked-up of 2,826 medications checked with no known interaction — see the full Thiamine list.
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.
- 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.
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.
Taking Thiamine and Bromocriptine Together: Common Questions
Is it safe to take Thiamine with Bromocriptine?
Do Thiamine and Bromocriptine have any of the same side effects?
Should I take Thiamine and Bromocriptine at the same time of day?
Are Thiamine and Bromocriptine used for the same thing?
How was the Thiamine and Bromocriptine combination checked?
Does Thiamine interact with any other medications?
Does Bromocriptine interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.