Cardarine + Efavirenz
Efavirenz brand name: Sustiva.
We found no known interaction between Cardarine and Efavirenz in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.
Cardarine and Efavirenz
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Efavirenz and Cardarine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
Worth understanding: our licensed dataset holds no drug-interaction record for Cardarine at all — not against Efavirenz, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
Cardarine safety at a glance
Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Cardarine in Pregnancy & Breastfeeding
When used orally or parenterally. Some metabolic modulators have been found to cause cancer in animals. Their safety in humans has not been tested. Avoid using.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center
See Every Supplement That Interacts With Efavirenz
This page covers Cardarine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Efavirenz page lists 159 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).
By severity: 3 major · 117 moderate · 39 minor.
From our pharmacist’s overview on the Efavirenz page
“Efavirenz (Sustiva) is an HIV medicine, so an interaction that weakens it can cost more than a bad day; it can invite viral resistance. That makes this a list to treat with genuine care.”
Reviewed by 2 · Jul 18, 2026
Taking Cardarine as Part of a Dietary Supplement Product? Check It for Interactions
We hold 18 real supplement products containing Cardarine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cardarine. Even though Cardarine itself has no known interaction with Efavirenz, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Cardarine and Efavirenz 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.
#1,122 of 1,452 supplements looked up here in the last 7 days
#906 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.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Cardarine reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Cardarine and Efavirenz records this page draws on were last updated June 22, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About Cardarine
What is Cardarine?
- Endurance and athletic performance
- Fat loss and body recomposition
- Bodybuilding cycles
- Increasing exercise capacity
Cardarine (GW501516) is a synthetic experimental drug, not a vitamin, herb, or true dietary supplement, even though it is often sold as one. Animal studies linked it to a higher risk of cancer, drug development was halted, and it is banned in sports — so it should not be used. There is no proven safe dose for humans.
Not applicable (synthetic chemical compound) · Capsules, tablets, oral liquids, powders (sold as a 'research chemical')
An interaction check asks whether these two react with each other — it does not ask whether Cardarine is a good idea for someone in your situation. Here is what our Cardarine record says about it on its own.
Cardarine: dosing
There is no established safe or approved dose of Cardarine for humans. It is not approved by the FDA for any condition, and no medical or pharmacy authority endorses a dosing plan.Doses listed on websites and forums are not based on reliable safety research and should not be trusted.
From our Cardarine monograph — the full record covers uses, side effects and every documented interaction.
About Efavirenz
What Is Efavirenz Used For?
Brand name: Sustiva
Efavirenz is used to treat HIV-1 (human immunodeficiency virus type 1) infection. It is always used together with other antiretroviral medicines — never on its own.
It is approved for adults and for children who are at least 3 months old and weigh at least 3.5 kg (about 7.7 lbs). Both the capsule and tablet forms are approved for this use.
Most-Reported Side Effects for Efavirenz
From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Cardarine
Browse every other medication we’ve checked against Cardarine — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Cardarine against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Ivermectin ›
- Losartan Potassium ›
- Abemaciclib ›
- Aspirin ›
- Acetaminophen ›
- Metoprolol ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Tadalafil ›
- Tirzepatide ›
- Methamphetamine ›
- Ibuprofen ›
- Warfarin Sodium ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Amitriptyline ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Amlodipine Besylate ›
- Bendamustine ›
- Methotrexate ›
- Bupropion ›
- Amphetamine ›
- Fluoxetine ›
- Doxycycline ›
- Azithromycin ›
- Acyclovir ›
- Pregabalin ›
- Lamotrigine ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Levothyroxine, Liothyronine ›
- Clonazepam ›
- Quetiapine ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Duloxetine ›
- Methylene Blue ›
- Buspirone ›
- Citalopram ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Cardarine list.
Cardarine References
The 1 references that drive our Cardarine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.
- What Should Tested Athletes Know About GW1516? Education, Spirit of Sport. U.S. Anti-Doping Agency (USADA). September 24, 2019. Available at: https://www.usada.org/spirit-of-sport/education/what-should-athletes-know-gw1516/
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Efavirenz Is Linked to Lower Levels of One Nutrient
Natural Medicines records Efavirenz as a medicine that can lower these. This is not an interaction with Cardarine — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Efavirenz nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Cardarine and Efavirenz Together: Common Questions
Is it safe to take Cardarine with Efavirenz?
Does Efavirenz interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Keep Exploring
Still Have a Question About Efavirenz and Cardarine?
Our pharmacists answer your medication & supplement questions — free.
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.