Drug & supplement interaction

Higenamine + 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 Higenamine can interact with; the most serious is rated moderate. Theoretically, higenamine might increase the levels and clinical effects of drugs metabolized by CYP2D6.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Higenamine and Tamoxifen Citrate

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

Why Are There 2 Interactions?

Higenamine interacts with whole categories of medication. Tamoxifen Citrate falls into 2 of those categories, so it can interact with Higenamine 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 2D6 (CYP2D6) SUBSTRATES

1 of 2

Why this applies to Tamoxifen Citrate

Tamoxifen Citrate falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Higenamine interacts with.

Theoretically, higenamine might increase the levels and clinical effects of drugs metabolized by CYP2D6.
In vitro research shows that higenamine inhibits CYP2D6 enzymes. However, this effect has not been reported 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 wrinkle with tamoxifen: it's actually a prodrug. Your body uses an enzyme called CYP2D6 to convert it into endoxifen, which is the form that does most of the real work fighting breast cancer. So anything that slows that enzyme down can mean less of the active form, not more.

Lab studies suggest higenamine may block CYP2D6. In theory, that could lower how much active tamoxifen you make, which matters because this is a medicine where steady, effective levels really count. I'll be honest though, this is only test-tube evidence and hasn't been shown in real people. Given the stakes, I'd skip higenamine here and check with your oncologist or pharmacist before adding any pre-workout or weight-loss supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Tamoxifen Citrate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, higenamine might increase the levels and clinical effects drugs metabolized by CYP3A4.
In vitro research shows that higenamine inhibits CYP3A4 enzymes by 21%. However, this effect has not been reported 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 wrinkle with tamoxifen: it's actually a prodrug, meaning your body has to convert it into its active form (called endoxifen) before it can fight breast cancer. Your liver enzymes, including CYP3A4, help do that conversion. The concern here is that higenamine showed some ability to block CYP3A4 in lab tests, which could in theory slow that activation and leave you with less of the active medicine you're counting on.

That said, this is based only on test-tube research (a weak 21% effect that's never been seen in real people), so I wouldn't lose sleep over it. Still, tamoxifen matters too much to take chances, and higenamine itself can stress your heart and blood pressure. Please loop in your oncologist or pharmacist before adding any pre-workout or weight-loss supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. 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

Higenamine Also Interacts With Other Medications

Higenamine has 890 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 890 No known interaction 1,940 (incl. Tamoxifen Citrate)
Taking anything else?

Check Another of Your Medications Against Higenamine

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

From our Q&A

Questions About Higenamine 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 Higenamine 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 Higenamine 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 Higenamine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 154 real supplement products containing Higenamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Higenamine. Your product may carry other ingredients that interact with Tamoxifen Citrate too, on top of Higenamine — 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 Higenamine 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 Higenamine
Top half

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

29 days ago today
Medication Tamoxifen Citrate
Top 25%

#468 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 Higenamine

What is Higenamine?

  • Weight loss and fat burning
  • Pre-workout energy and performance
  • Appetite suppression
  • Athletic stimulant
  • Traditional medicine remedies

Higenamine is a plant-based stimulant compound added to many weight-loss and pre-workout supplements, but there is very little human evidence that it works and real concerns about heart and blood pressure effects. It is banned in sports by the World Anti-Doping Agency (WADA), and product labels often list inaccurate amounts, so most people should approach it with caution and talk to a pharmacist or doctor first.

Read the full Higenamine 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 & Higenamine

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

0Major
890Moderate
0Minor
1,939No known interaction
890 Moderate 1,939 No interaction
Moderate

890 interactions

Showing 60 of 890 moderate interactions — see all 890 on the Higenamine page.

No interaction 1,939 drugs checked — show the list

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

Showing the 60 most looked-up of 1,939 medications checked with no known interaction — see the full Higenamine list.

See the full Higenamine 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
Higenamine 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 Higenamine and Tamoxifen Citrate Together: Common Questions

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

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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.