Arimistane + Letrozole, Ribociclib Succinate
Letrozole, Ribociclib Succinate brand name: Kisqali Femara Co-Pack.
Arimistane has a moderate interaction with Letrozole, Ribociclib Succinate. It is believed that Arimistane inhibits the aromatase enzyme, which may interact with other aromatase inhibitors.
Read the full interaction reportArimistane and Letrozole, Ribociclib Succinate
Here is the interaction we found between these two, with the evidence behind it.
Aromatase Inhibitors
Why this applies to Letrozole, Ribociclib Succinate
Letrozole, Ribociclib Succinate falls under Aromatase Inhibitors — the group Arimistane interacts with.
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..
Here's the thing about your Kisqali Femara combo: the letrozole part is itself an aromatase inhibitor. Its whole job is to block aromatase so your body makes less estrogen. Arimistane is also an aromatase inhibitor, so taking both is like doubling down on the same action. You're not getting a useful boost, just a higher chance of low-estrogen side effects piling up.
That can mean worse hot flashes, joint and bone aches, fatigue, and mood changes. There's also a real concern about added strain on the liver, since ribociclib already requires liver monitoring. Please don't start or stop anything on your own. Run this past your oncologist or pharmacist first, since you're already on a carefully dosed cancer regimen.
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Arimistane Also Interacts With Other Medications
Arimistane has 3 moderate known drug interactions in our database — the Letrozole, Ribociclib Succinate one above is one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Arimistane
We haven’t checked that one against Arimistane yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Arimistane. Pick one to open its full report.
See Every Supplement That Interacts With Letrozole, Ribociclib Succinate
This page covers Arimistane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Letrozole, Ribociclib Succinate page lists 155 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), Cesium (major) and Ephedra (major).
By severity: 8 major · 109 moderate · 38 minor.
From our pharmacist’s overview on the Letrozole, Ribociclib Succinate page
“Grapefruit tops my worry list for anyone taking the Kisqali Femara Co-Pack (letrozole and ribociclib), because it blocks the enzyme, CYP3A4, that clears ribociclib and can push levels of this breast cancer drug higher than intended. That enzyme thread runs through 121 of the 155 ingredients on this page, and with eight rated major, rea…”
Reviewed by 2 · Jul 18, 2026
Taking Arimistane as Part of a Dietary Supplement Product? Check It for Interactions
We hold 80 real supplement products containing Arimistane, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Arimistane. Your product may carry other ingredients that interact with Letrozole, Ribociclib Succinate too, on top of Arimistane — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Arimistane and Letrozole, Ribociclib Succinate 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.
#476 of 1,452 supplements looked up here in the last 7 days
#404 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.
About Arimistane
What is Arimistane?
- Lowering estrogen levels
- Post-cycle therapy after steroid or prohormone use
- Reducing gynecomastia ('gyno')
- Boosting testosterone
- Bodybuilding and physique support
Arimistane (sometimes sold as Estrovade) is a synthetic aromatase inhibitor marketed as a dietary supplement to lower estrogen and raise testosterone, often during or after steroid or prohormone cycles. It is not a true dietary ingredient, has very little human safety data, and U.S. regulators have warned against products containing aromatase inhibitors. Talk to a pharmacist or doctor before using it.
Other Drugs & Arimistane
Browse every other medication we’ve checked against Arimistane — 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 Arimistane against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Tadalafil ›
- Acetaminophen ›
- Clopidogrel ›
- Valacyclovir ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Sumatriptan ›
- Ibuprofen ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Acyclovir ›
- Bupropion ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Lamotrigine ›
- Fluoxetine ›
- Methotrexate ›
- Acetaminophen, Codeine ›
- Gabapentin ›
- Amphetamine ›
- Pregabalin ›
- Isotretinoin ›
- Dextroamphetamine ›
- Azithromycin ›
- Clonazepam ›
- Quetiapine ›
- Omeprazole ›
- Amlodipine Besylate ›
- Methylene Blue ›
- Duloxetine ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Naproxen ›
- Bisoprolol ›
Showing the 60 most looked-up of 2,826 medications checked with no known interaction — see the full Arimistane list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Taking Arimistane and Letrozole, Ribociclib Succinate Together: Common Questions
Can you take Arimistane with Letrozole, Ribociclib Succinate?
How serious is the Arimistane and Letrozole, Ribociclib Succinate interaction?
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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.