Drug & supplement interaction

Andarine + Testosterone Undecanoate

Testosterone Undecanoate brand names: Andriol, Aveed, Jatenzo, Kyzatrex.

Moderate Interaction
The bottom line Moderate

Andarine has a moderate interaction with Testosterone Undecanoate. Due to its androgenic properties, Andarine (S-4) may theoretically interact with other androgenic drugs, potentially increasing the risk of side effects associated with androgenic activity (source: https://pubmed.ncbi.nlm.nih.gov/12604714/).

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

Andarine and Testosterone Undecanoate

Here is the interaction we found between these two, with the evidence behind it.

Moderate

Androgens

Why this applies to Testosterone Undecanoate

Testosterone Undecanoate falls under Androgens — the group Andarine interacts with.

Due to its androgenic properties, Andarine (S-4) may theoretically interact with other androgenic drugs, potentially increasing the risk of side effects associated with androgenic activity (source: https://pubmed.ncbi.nlm.nih.gov/12604714/). These side effects can include masculinization, virilization, acne, hair loss, increased libido, aggression, mood changes, and liver toxicity.
Severity Moderate Likelihood Possible Evidence C

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: Andarine (S-4) acts a lot like testosterone because it latches onto the same androgen receptors in your body. So if you're already on testosterone undecanoate (brands like Jatenzo, Aveed, or Kyzatrex), adding Andarine basically stacks one androgen on top of another. They push in the same direction, which can amplify the very effects and side effects you'd expect from testosterone.

In real terms, that could mean more acne, oily skin, hair thinning, mood swings or irritability, a higher red blood cell count, and added strain on the liver. This is rated a moderate, theoretical concern, so it's not proven in studies, but the overlap makes sense. On top of that, Andarine isn't a legal or safe supplement, so I'd steer clear and talk with your doctor or pharmacist before combining anything with your testosterone.

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

Andarine Also Interacts With Other Medications

Andarine has 8 moderate known drug interactions in our database — the Testosterone Undecanoate one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Andarine

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

From our Q&A

Questions About Andarine or Testosterone Undecanoate

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

This page covers Andarine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Testosterone Undecanoate page lists 200 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 7 major · 150 moderate · 43 minor.

From our pharmacist’s overview on the Testosterone Undecanoate page

“The supplement list for testosterone undecanoate (Jatenzo, Aveed, Kyzatrex, Andriol) deserves real attention before you combine it with much of anything, and the seven major-rated entries are where I would start. Most of the 200 ingredients on file, 121 of them, can change how the body handles this hormone through the CYP3A4 enzyme; gr…”

Reviewed by 2 · Jul 18, 2026

Open the Testosterone Undecanoate interaction page

One more smart check

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

We hold 13 real supplement products containing Andarine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Andarine. Your product may carry other ingredients that interact with Testosterone Undecanoate too, on top of Andarine — 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 Andarine and Testosterone Undecanoate 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 Andarine
Steady interest

#1,088 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Testosterone Undecanoate
Top 25%

#402 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 Andarine

What is Andarine?

Andarine
  • Muscle building
  • Strength gains
  • Fat loss / body recomposition
  • Athletic performance enhancement
  • Bone density support

Andarine (S-4) is a synthetic selective androgen receptor modulator (SARM) that is not approved by the FDA for human use and is banned in sports. It is not a legal dietary supplement ingredient, its long-term safety in people is unknown, and reported side effects include vision changes and possible liver and hormone problems. Because of these risks and its illegal status, we do not recommend using it.

Read the full Andarine monograph & all interactions
Medication

About Testosterone Injection

What Is Testosterone Injection Used For?

Brand names: Andriol, Aveed, Jatenzo, Kyzatrex

Testosterone injection is primarily used in men whose bodies do not produce enough testosterone on their own — a condition called hypogonadism. This includes primary hypogonadism (a problem with the testicles themselves, such as from injury, infection, or surgery) and hypogonadotropic hypogonadism (caused by problems in the brain's hormone signaling from the hypothalamus or pituitary gland). It is also used to stimulate puberty in carefully selected adolescent males with clearly delayed puberty who have not responded to other support.

Testosterone Enanthate Injection is also approved for use in women with advanced, inoperable metastatic breast cancer (specifically skeletal metastases) who are one to five years past menopause, or in premenopausal women with hormone-responsive breast cancer who have had their ovaries removed. This use should be directed by an oncologist. Aveed (testosterone undecanoate) is specifically approved for male hypogonadism only.

See full Testosterone Injection drug information
Keep checking

Other Drugs & Andarine

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

0Major
8Moderate
0Minor
2,821No known interaction
Moderate

8 interactions

No interaction 2,821 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Andarine and Testosterone Undecanoate Together: Common Questions

Can you take Andarine with Testosterone Undecanoate?
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.
How serious is the Andarine and Testosterone Undecanoate 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 Testosterone Undecanoate and Andarine?

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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.