Drug & supplement interaction

Guggul + Tamoxifen Citrate

Tamoxifen Citrate brand names: Nolvadex, Soltamox.

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

Tamoxifen Citrate falls into 2 drug categories that Guggul can interact with; the most serious is rated moderate. Theoretically, guggul might reduce the effects of CYP3A4 substrates.

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

Guggul and Tamoxifen Citrate

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

Why Are There 2 Interactions?

Guggul interacts with whole categories of medication. Tamoxifen Citrate falls into 2 of those categories, so it can interact with Guggul 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 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Tamoxifen Citrate

Tamoxifen Citrate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Guggul interacts with.

Theoretically, guggul might reduce the effects of CYP3A4 substrates.
In vitro research shows that guggul constituents known as guggulsterones can induce CYP3A4.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the thing about tamoxifen: it's actually a prodrug. Your liver has to convert it into its active form (mostly through enzymes like CYP2D6 and CYP3A4) before it can do its real job of blocking estrogen in breast tissue. So how your body processes it really matters.

Lab and animal studies hint that guggul may speed up the CYP3A4 enzyme. In theory, that could shift how tamoxifen is handled and possibly weaken the protection you're counting on, which is a big deal for a cancer medicine. I want to be honest, though: this is only test-tube and animal evidence, so we don't truly know it happens in people. Given the stakes, I'd run guggul by your oncologist or pharmacist before using it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brobst DE, Ding X, Creech KL, et al. Guggulsterone activates multiple nuclear receptors and induces CYP3A gene expression through the pregnane X receptor. J Pharmacol Exp Ther 2004;310:528-35. PubMed
Moderate

TAMOXIFEN (Nolvadex)

2 of 2
Theoretically, guggul might interfere with tamoxifen therapy.
In vitro research shows that guggul has estrogen-alpha receptor agonist activity.
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 concern with pairing guggul and tamoxifen. Tamoxifen works by blocking estrogen from reaching breast cancer cells, which is how it helps treat and prevent breast cancer. In lab studies, guggul appears to act on estrogen receptors in a way that mimics estrogen. If that happens in the body, it could theoretically work against what tamoxifen is trying to do, which is the opposite of what you want when fighting an estrogen-sensitive cancer.

I want to be honest about how solid this is: it's based only on test-tube research, not on real patients, so we don't truly know if it matters in people. Still, because tamoxifen is so important, I'd play it safe. Please check with your oncologist or pharmacist before using guggul.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brobst DE, Ding X, Creech KL, et al. Guggulsterone activates multiple nuclear receptors and induces CYP3A gene expression through the pregnane X receptor. J Pharmacol Exp Ther 2004;310:528-35. 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

Guggul Also Interacts With Other Medications

Guggul has 756 moderate known drug interactions in our database — the Tamoxifen Citrate one above is among them. If you take anything else, check it against the full list below.

Moderate 756 No known interaction 2,074 (incl. Tamoxifen Citrate)
Taking anything else?

Check Another of Your Medications Against Guggul

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

From our Q&A

Questions About Guggul or Tamoxifen Citrate

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

This page covers Guggul only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tamoxifen Citrate page lists 210 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 166 moderate · 33 minor.

From our pharmacist’s overview on the Tamoxifen Citrate page

“Tamoxifen (Nolvadex, Soltamox) often stands between a breast cancer patient and a recurrence, so the stakes on this page run higher than usual. Eleven of the 210 supplements and herbs on file carry a major rating, and those eleven deserve your attention ahead of everything else.”

Reviewed by 2 · Jul 18, 2026

Open the Tamoxifen Citrate interaction page

One more smart check

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

We hold 955 real supplement products containing Guggul, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Guggul. Your product may carry other ingredients that interact with Tamoxifen Citrate too, on top of Guggul — 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 Guggul and Tamoxifen Citrate 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 Guggul
Top 25%

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

29 days ago today
Medication Tamoxifen Citrate
Top 25%

#413 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 Guggul

What is Guggul?

Guggul
  • High cholesterol
  • Joint pain and arthritis
  • Weight management
  • Acne
  • Skin conditions

Guggul is a gum resin from the Commiphora wightii tree, long used in Ayurvedic medicine for cholesterol, joint, and skin problems. Modern studies are mixed and often low-quality, and it can cause stomach upset and skin rashes. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Guggul monograph & all interactions
Medication

About Tamoxifen

What Is Tamoxifen Used For?

Brand names: Nolvadex, Soltamox

Tamoxifen is used to treat estrogen receptor-positive metastatic breast cancer in both women and men, and as follow-up (adjuvant) therapy after surgery for early-stage breast cancer in women. It also reduces the occurrence of cancer in the opposite breast when used as adjuvant therapy.

In women with ductal carcinoma in situ (DCIS — an early, non-invasive breast change) following surgery and radiation, tamoxifen lowers the risk of developing invasive breast cancer. It is also approved to reduce the risk of breast cancer in women who are at high risk but have not yet been diagnosed. Both Tamoxifen Citrate tablets and Soltamox oral solution share these indications.

See full Tamoxifen drug information
Keep checking

Other Drugs & Guggul

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

0Major
756Moderate
0Minor
2,073No known interaction
756 Moderate 2,073 No interaction
Moderate

756 interactions

Showing 60 of 756 moderate interactions — see all 756 on the Guggul page.

No interaction 2,073 drugs checked — show the list

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

Showing the 60 most looked-up of 2,073 medications checked with no known interaction — see the full Guggul list.

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

Can you take Guggul with Tamoxifen Citrate?
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 Guggul and Tamoxifen Citrate?
Tamoxifen Citrate belongs to more than one drug category, and Guggul 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 Guggul and Tamoxifen Citrate 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 Tamoxifen Citrate and Guggul?

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.