Drug & supplement interaction

Black Seed + Nateglinide

Nateglinide brand name: Starlix.

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

Nateglinide falls into 2 drug categories that Black Seed can interact with; the most serious is rated moderate. Theoretically, black seed might increase levels of drugs metabolized by CYP2C9.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Black Seed and Nateglinide

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Black Seed interacts with whole categories of medication. Nateglinide falls into 2 of those categories, so it can interact with Black Seed in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

1 of 2

Why this applies to Nateglinide

Nateglinide falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Black Seed interacts with.

Theoretically, black seed might increase levels of drugs metabolized by CYP2C9.
In vitro research suggests that thymoquinone, a constituent of black seed, can decrease the metabolism of phenytoin by a mechanism possibly related to the inhibition of CYP2C9. The effect of black seed on CYP2C9 is unclear. This has not been shown in humans.
Severity Moderate Likelihood Possible Evidence D

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 situation with these two. Your body relies on a liver enzyme called CYP2C9 to clear nateglinide. Black seed (specifically thymoquinone in the seed oil) might slow that enzyme down a bit, so in theory nateglinide could hang around longer and push your insulin release a little harder than expected.

What that could look like in real life is low blood sugar (hypoglycemia), with signs like shakiness, sweating, dizziness, confusion, or a racing heart. I want to be honest, though: this is only a theoretical concern from lab work, not something proven in people, and food-amount sprinkles of black seed are unlikely to matter. Concentrated supplement doses are the bigger question mark. If you want to take black seed, check with your pharmacist or doctor first and keep an eye on your blood sugar readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wang Z, Wang X, Wang Z, et al. Potential herb-drug interaction risk of thymoquinone and phenytoin. Chem Biol Interact. 2022;353:109801. PubMed
Moderate

ANTIDIABETES DRUGS

2 of 2

Nateglinide also falls under ANTIDIABETES DRUGS.

Theoretically, taking black seed with antidiabetes drugs might increase the risk of hypoglycemia.
Some clinical research and numerous animal studies suggest that black seed, especially its constituent thymoquinone, can have hypoglycemic effects.
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 simple version: nateglinide (Starlix) already works by nudging your pancreas to release more insulin, which lowers your blood sugar. Black seed appears to have its own mild blood-sugar-lowering effect, mostly thanks to a compound called thymoquinone. So when you stack the two together, the worry is that your sugar could dip too low. That's called hypoglycemia, and it can show up as shakiness, sweating, dizziness, a racing heart, confusion, or feeling suddenly weak or hungry.

The evidence here is on the lighter side (some early human studies plus a lot of animal work), so this isn't a guaranteed problem. Food-amount sprinkles of the spice are unlikely to matter much, but concentrated supplement doses are more of a question mark. Please don't stop either one on your own. Just loop in your pharmacist or doctor, and keep an eye on your blood sugar readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Meral, I., Yener, Z., Kahraman, T., and Mert, N. Effect of Nigella sativa on glucose concentration, lipid peroxidation, anti-oxidant defence system and liver damage in experimentally-induced diabetic rabbits. J Vet.Med A Physiol Pathol.Clin Med 2001;48(1
  2. Fararh, K. M., Atoji, Y., Shimizu, Y., Shiina, T., Nikami, H., and Takewaki, T. Mechanisms of the hypoglycaemic and immunopotentiating effects of Nigella sativa L. oil in streptozotocin-induced diabetic hamsters. Res Vet.Sci 2004;77(2):123-129. PubMed
  3. Kaleem, M., Kirmani, D., Asif, M., Ahmed, Q., and Bano, B. Biochemical effects of Nigella sativa L seeds in diabetic rats. Indian J Exp.Biol. 2006;44(9):745-748.
  4. Hawsawi, Z. A., Ali, B. A., and Bamosa, A. O. Effect of Nigella sativa (Black Seed) and thymoquinone on blood glucose in albino rats. Ann.Saudi Med 2001;21(3-4):242-244.
  5. Meddah, B., Ducroc, R., El Abbes, Faouzi M., Eto, B., Mahraoui, L., Benhaddou-Andaloussi, A., Martineau, L. C., Cherrah, Y., and Haddad, P. S. Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats. J Ethnopharmacol. PubMed
  6. Najmi, A., Nasiruddin, M., Khan, R. A., and Haque, S. F. Effect of Nigella sativa oil on various clinical and biochemical parameters of insulin resistance syndrome. Int J Diabetes Dev.Ctries. 2008;28(1):11-14.
  7. Bamosa AO, Kaatabi H, Lebdaa FM, et al. Effect of Nigella sativa seeds on the glycemic control of patients with type 2 diabetes mellitus. Indian J Physiol Pharmacol 2010;54:344-54.
  8. Kaatabi H, Bamosa AO, Badar A, et al. Nigella sativa improves glycemic control and ameliorates oxidative stress in patients with type 2 diabetes mellitus: placebo controlled participant blinded clinical trial. PLoS One 2015;10:e0113486. PubMed
  9. Kooshki A, Tofighiyan T, Rastgoo N, Rakhshani MH, Miri M. Effect of Nigella sativa oil supplement on risk factors for cardiovascular diseases in patients with type 2 diabetes mellitus. Phytother Res. 2020.
  10. Moustafa HAM, El Wakeel LM, Halawa MR, Sabri NA, El-Bahy AZ, Singab AN. Effect of Nigella sativa oil versus metformin on glycemic control and biochemical parameters of newly diagnosed type 2 diabetes mellitus patients. Endocrine 2019;65(2):286-94. PubMed
  11. Hadi S, Daryabeygi-Khotbehsara R, Mirmiran P, et al. Effect of Nigella sativa oil extract on cardiometabolic risk factors in type 2 diabetes: A randomized, double-blind, placebo-controlled clinical trial. Phytother Res 2021;35(7):3747-3755.
  12. Ali SM, Chen P, Sheikh S, et al. Thymoquinone with metformin decreases fasting, post prandial glucose, and HbA1c in type 2 diabetic patients. Drug Res (Stuttg) 2021;71(6):302-306. PubMed
  13. Tavakoli-Rouzbehani OM, Abbasnezhad M, Kheirouri S, Alizadeh M. Effects of Nigella sativa oil supplementation on selected metabolic parameters and anthropometric indices in patients with coronary artery disease: A randomized, double-blind, placebo-control

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

Black Seed Also Interacts With Other Medications

Black Seed has 911 moderate known drug interactions in our database — the Nateglinide one above is among them. If you take anything else, check it against the full list below.

Moderate 911 No known interaction 1,919 (incl. Nateglinide)
Taking anything else?

Check Another of Your Medications Against Black Seed

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

From our Q&A

Questions About Black Seed or Nateglinide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Black Seed or Nateglinide, 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 Nateglinide

This page covers Black Seed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nateglinide page lists 290 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), Acai (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 2 major · 241 moderate · 47 minor.

From our pharmacist’s overview on the Nateglinide page

“People who take nateglinide (Starlix) with meals for type 2 diabetes are often drawn to supplements marketed for blood sugar, and that overlap is why these 290 interactions warrant real caution. Some 239 of the ingredients affect blood sugar on their own, most pushing it lower, so stacking them on nateglinide raises the odds of hypogly…”

Reviewed by 2 · Jul 18, 2026

Open the Nateglinide interaction page

One more smart check

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

We hold 226 real supplement products containing Black Seed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Black Seed. Your product may carry other ingredients that interact with Nateglinide too, on top of Black Seed — 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 Black Seed and Nateglinide 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 Black Seed
Top 25%

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

29 days ago today
Medication Nateglinide
Steady interest

#2,049 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 Black Seed

What is Black Seed?

Black Seed
  • Respiratory support (asthma, allergies, cough)
  • Digestive upset
  • Immune support
  • Blood sugar and cholesterol support
  • General inflammation

Black seed (Nigella sativa) is a traditional spice and remedy that has been studied for asthma, blood sugar, cholesterol, and blood pressure, with early research showing some promise but no firmly proven benefits. It is generally well tolerated in food amounts, but supplement-strength doses are less studied, so talk to your pharmacist or doctor before using it—especially if you are pregnant, breastfeeding, or take other medicines.

Read the full Black Seed monograph & all interactions
Medication

About Nateglinide

What Is Nateglinide Used For?

Brand name: Starlix

Nateglinide tablets are used to help improve blood sugar (glucose) control in adults with type 2 diabetes. It is always used together with diet and exercise — not as a replacement for them.

Nateglinide is not for type 1 diabetes, and it is not used to treat diabetic ketoacidosis (a serious complication where the blood becomes dangerously acidic).

See full Nateglinide drug information
Keep checking

Other Drugs & Black Seed

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

0Major
911Moderate
0Minor
1,918No known interaction
911 Moderate 1,918 No interaction
Moderate

911 interactions

Showing 60 of 911 moderate interactions — see all 911 on the Black Seed page.

No interaction 1,918 drugs checked — show the list

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

Showing the 60 most looked-up of 1,918 medications checked with no known interaction — see the full Black Seed list.

See the full Black Seed interactions page
See every supplement checked against Nateglinide, 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
Black Seed monograph › Uses, safety, and every drug interaction in one place Nateglinide supplement interactions › Every supplement checked against Nateglinide, ranked by severity Nateglinide 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 Black Seed and Nateglinide Together: Common Questions

Can you take Black Seed with Nateglinide?
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.
Why are there 2 interactions listed for Black Seed and Nateglinide?
Nateglinide belongs to more than one drug category, and Black Seed interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Black Seed and Nateglinide 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 Nateglinide and Black Seed?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.