Drug & supplement interaction

Milk Thistle + Insulin Aspart

Insulin Aspart brand name: Fiasp.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Milk Thistle has a moderate interaction with Insulin Aspart. Taking milk thistle with antidiabetes drugs may increase the risk of hypoglycemia.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Milk Thistle and Insulin Aspart

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIDIABETES DRUGS

Why this applies to Insulin Aspart

Insulin Aspart falls under ANTIDIABETES DRUGS — the group Milk Thistle interacts with.

Taking milk thistle with antidiabetes drugs may increase the risk of hypoglycemia.
Clinical research shows that milk thistle extract, alone or along with tree turmeric extract, can lower blood glucose levels and glycated hemoglobin (HbA1c) in patients with type 2 diabetes, including those already taking antidiabetes drugs. Additionally, animal research shows that milk thistle extract increases the metformin maximum plasma concentration and area under the curve and decreases the renal clearance of metformin, due to inhibition of the multi-drug and toxin extrusion protein 1 (MATE1) renal tubular transport protein.
Severity Moderate Likelihood Possible Evidence B

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the practical takeaway if you use insulin aspart (Fiasp) and are thinking about milk thistle. Some lower quality studies suggest milk thistle (silymarin) can lower blood sugar and HbA1c on its own. Since insulin aspart already pushes your sugar down, stacking the two could add up and make low blood sugar (hypoglycemia) more likely. That can look like shakiness, sweating, a racing heart, confusion, or feeling lightheaded.

The evidence here is modest, not airtight, so this isn't a reason to panic. Still, if you decide to try milk thistle, it's smart to check your blood sugar a bit more closely at first and watch for lows. Please don't change your insulin dose on your own. Talk with your pharmacist or doctor so they can guide any adjustments safely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Huseini HF, Larijani B, Heshmat R, et al. The efficacy of Silybum marianum (L.) Gaertn. (silymarin) in the treatment of type II diabetes: a randomized, double-blind, placebo-controlled, clinical trial. Phytother Res 2006;20;1036-9.
  2. Hussain, S. A. Silymarin as an adjunct to glibenclamide therapy improves long-term and postprandial glycemic control and body mass index in type 2 diabetes. J.Med.Food 2007;10(3):543-547. PubMed
  3. Fallah Huseini, H., Larijani, B., Fakhrzadeh, H., Rajabi Pour, B., Akhondzadeh, S., Toliat, T., and Heshmat, R. The clinical trial of Silybum Marianum seed extract (Silymarin) on type II diabetic patients with hyperlipidemia. Iran J.Diabetes Lipid Disord
  4. Velussi M, Cernigoi AM, Viezzoli L, and et al. Silymarin reduces hyperinsulinemia, malondialdehyde levels, and daily insulin need in cirrhotic diabetic patients. Curr Ther Res 1993;53(5):533-545. DOI
  5. Derosa G, Romano D, D'Angelo A, Maffioli P. Berberis aristata/Silybum marianum fixed combination (Berberol(®)) effects on lipid profile in dyslipidemic patients intolerant to statins at high dosages: a randomized, placebo-controlled, clinical trial. Phyto PubMed
  6. Di Pierro F, Bellone I, Rapacioli G, Putignano P. Clinical role of a fixed combination of standardized Berberis aristata and Silybum marianum extracts in diabetic and hypercholesterolemic patients intolerant to statins. Diabetes Metab Syndr Obes. 2015;8:8 PubMed
  7. Di Pierro F, Villanova N, Agostini F, Marzocchi R, Soverini V, Marchesini G. Pilot study on the additive effects of berberine and oral type 2 diabetes agents for patients with suboptimal glycemic control. Diabetes Metab Syndr Obes. 2012;5:213-7. PubMed
  8. Guarino G, Strollo F, Carbone L, et al. Bioimpedance analysis, metabolic effects and safety of the association Berberis aristata/Bilybum marianum: a 52-week double-blind, placebo-controlled study in obese patients with type 2 diabetes. J Biol Regul Homeos
  9. Ebrahimpour-Koujan S, Gargari BP, Mobasseri M, Valizadeh H, Asghari-Jafarabadi M. Lower glycemic indices and lipid profile among type 2 diabetes mellitus patients who received novel dose of Silybum marianum (L.) Gaertn. (silymarin) extract supplement: A T
  10. Mohammadi S, Asbaghi O, Afrisham R, et al. Impacts of Supplementation with Silymarin on Cardiovascular Risk Factors: A Systematic Review and Dose-Response Meta-Analysis. Antioxidants (Basel) 2024;13(4):390. PubMed
  11. Duan X, Bai W, Hu J, et al. Inhibitory effect of flavonoids on multidrug and toxin extrusion protein 1 function: Implications for food/herb-drug interaction and drug-induced kidney injury. J Appl Toxicol 2024;44(9):1388-1402. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Milk Thistle Also Interacts With Other Medications

Milk Thistle has 253 moderate, 700 minor known drug interactions in our database — the Insulin Aspart one above is one of them. If you take anything else, check it against the full list below.

Moderate 253 Minor 700 No known interaction 1,877 (incl. Insulin Aspart)
Taking anything else?

Check Another of Your Medications Against Milk Thistle

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

From our Q&A

Questions About Milk Thistle or Insulin Aspart

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Milk Thistle or Insulin Aspart, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Insulin Aspart

This page covers Milk Thistle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin Aspart page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate), Agaricus Mushroom (moderate) and Agmatine (moderate).

By severity: 1 major · 208 moderate · 30 minor.

From our pharmacist’s overview on the Insulin Aspart page

“Every one of the 239 supplements listed for insulin aspart (Fiasp) touches the same thing the drug exists to manage, blood sugar, so this list warrants genuine care rather than a quick skim. Most entries add to insulin's glucose-lowering effect, raising the risk of hypoglycemia, and with a rapid-acting mealtime insulin a low can become…”

Reviewed by 2 · Jul 18, 2026

Open the Insulin Aspart interaction page

One more smart check

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

We hold 4,560 real supplement products containing Milk Thistle, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Milk Thistle. Your product may carry other ingredients that interact with Insulin Aspart too, on top of Milk Thistle — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Milk Thistle and Insulin Aspart 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 Milk Thistle
Top 5%

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

29 days ago today
Medication Insulin Aspart
Steady interest

#1,799 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.

Supplement

About Milk Thistle

What is Milk Thistle?

Milk Thistle
  • Liver health and protection
  • Hepatitis
  • Cirrhosis
  • Gallbladder problems
  • High cholesterol
  • Type 2 diabetes support

Milk thistle is a popular herbal supplement most often used for liver health, and its main active component is a group of compounds called silymarin. While it is generally well tolerated, the scientific evidence that it meaningfully improves liver disease or other conditions is mixed and far from conclusive. Talk with your pharmacist or doctor before using it, especially if you have a liver condition or take other medicines.

Read the full Milk Thistle monograph & all interactions
Medication

About Insulin Aspart (rDNA Origin) Injection

What Is Insulin Aspart (rDNA Origin) Injection Used For?

Brand name: Fiasp

Insulin aspart is used to improve blood sugar (glucose) control in people with diabetes mellitus. It is approved for both type 1 and type 2 diabetes in adults, and for diabetes mellitus in pediatric patients.

Insulin Aspart Protamine and Insulin Aspart Mix 70/30 is a pre-mixed product that combines a rapid-acting and an intermediate-acting insulin aspart. It is approved to improve blood sugar control in adult patients with diabetes mellitus. It is not recommended for treating diabetic ketoacidosis, and because its ratio of rapid-acting to intermediate-acting insulin is fixed, it does not allow for separate mealtime versus background dose adjustments.

See full Insulin Aspart (rDNA Origin) Injection drug information
Keep checking

Other Drugs & Milk Thistle

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

0Major
253Moderate
700Minor
1,876No known interaction
253 Moderate 700 Minor 1,876 No interaction
Moderate

253 interactions

Showing 60 of 253 moderate interactions — see all 253 on the Milk Thistle page.

Minor

700 interactions

Showing 60 of 700 minor interactions — see all 700 on the Milk Thistle page.

No interaction 1,876 drugs checked — show the list

We also checked Milk Thistle against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,876 medications checked with no known interaction — see the full Milk Thistle list.

See the full Milk Thistle interactions page
See every supplement checked against Insulin Aspart, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Milk Thistle monograph › Uses, safety, and every drug interaction in one place Insulin Aspart supplement interactions › Every supplement checked against Insulin Aspart, ranked by severity Insulin Aspart (rDNA Origin) Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Milk Thistle and Insulin Aspart Together: Common Questions

Can you take Milk Thistle with Insulin Aspart?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Milk Thistle and Insulin Aspart interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Insulin Aspart and Milk Thistle?

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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.