Drug & supplement interaction

L-arginine + Testosterone Enanthate

Testosterone Enanthate brand name: Xyosted.

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

L-arginine has a minor interaction with Testosterone Enanthate. Theoretically, concomitant use of L-arginine and testosterone might have additive effects.

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

L-arginine and Testosterone Enanthate

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

Minor

TESTOSTERONE

Theoretically, concomitant use of L-arginine and testosterone might have additive effects.
In clinical research, L-arginine increases the level of testosterone in male patients with erectile dysfunction. The clinical significance of this finding is unclear.
Severity Minor 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 honest picture if you're using L-arginine alongside your testosterone enanthate (Xyosted) injections. Some early research suggests L-arginine may nudge testosterone levels up a bit, mostly studied in men dealing with erectile dysfunction. In theory, stacking it on top of testosterone you're already injecting could add together. But I want to be clear: this is a theoretical concern based on how things work on paper, not strong proof that it causes problems.

If anything did add up, you'd watch for the usual testosterone-related effects, things like acne, mood changes, fluid retention, or a higher red blood cell count over time. This is rated a minor interaction, so I wouldn't lose sleep over it. Still, since your doctor checks your levels with lab work, just mention the L-arginine so they can keep an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. El Taieb M, Hegazy E, Ibrahim A. Daily oral l-arginine plus tadalafil in diabetic patients with erectile dysfunction: A double-blinded, randomized, controlled clinical trial. J Sex Med. 2019;16(9):1390-1397.
  2. Abu El-Hamd M, Hegazy EM. Comparison of the clinical efficacy of daily use of L-arginine, tadalafil and combined L-arginine with tadalafil in the treatment of elderly patients with erectile dysfunction. Andrologia. 2020;52(7):e13640. 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

L-arginine Also Interacts With Other Medications

L-arginine has 395 moderate, 7 minor known drug interactions in our database — the Testosterone Enanthate one above is one of them. If you take anything else, check it against the full list below.

Moderate 395 Minor 7 No known interaction 2,428 (incl. Testosterone Enanthate)
Taking anything else?

Check Another of Your Medications Against L-arginine

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

From our Q&A

Questions About L-arginine or Testosterone Enanthate

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

This page covers L-arginine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Testosterone Enanthate page lists 184 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: 6 major · 134 moderate · 44 minor.

From our pharmacist’s overview on the Testosterone Enanthate page

“Beer and wine both carry major ratings on this list, because heavy alcohol use can compound the strain testosterone enanthate (Xyosted) already places on the liver. That liver theme runs through 38 of the 184 ingredients on file, Siberian cocklebur among them, and with six interactions rated major overall, this page deserves genuine ca…”

Reviewed by 2 · Jul 18, 2026

Open the Testosterone Enanthate interaction page

One more smart check

Taking L-arginine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 26 real supplement products containing L-arginine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-arginine. Your product may carry other ingredients that interact with Testosterone Enanthate too, on top of L-arginine — 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 L-arginine and Testosterone Enanthate 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 L-arginine
Steady interest

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

29 days ago today
Medication Testosterone Enanthate
Top half

#933 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 L-arginine

What is L-arginine?

L-arginine
  • High blood pressure
  • Erectile dysfunction
  • Athletic performance
  • Chest pain (angina)
  • Improving blood flow

L-arginine is an amino acid that the body uses to make nitric oxide, a substance that helps blood vessels relax and widen. It is popularly used for blood pressure, erectile dysfunction, and exercise, but the evidence is mixed and stronger for some uses than others. It is generally well tolerated in healthy adults, but talk with a pharmacist or doctor before using it, especially if you have heart problems or take other medicines.

Read the full L-arginine monograph & all interactions
Medication

About Testosterone Injection

What Is Testosterone Injection Used For?

Brand name: Xyosted

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 & L-arginine

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

0Major
395Moderate
7Minor
2,427No known interaction
395 Moderate 7 Minor 2,427 No interaction
Moderate

395 interactions

Showing 60 of 395 moderate interactions — see all 395 on the L-arginine page.

Minor

7 interactions

No interaction 2,427 drugs checked — show the list

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

Showing the 60 most looked-up of 2,427 medications checked with no known interaction — see the full L-arginine list.

See the full L-arginine interactions page
See every supplement checked against Testosterone Enanthate, 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
L-arginine monograph › Uses, safety, and every drug interaction in one place Testosterone Enanthate supplement interactions › Every supplement checked against Testosterone Enanthate, ranked by severity Testosterone Injection 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 L-arginine and Testosterone Enanthate Together: Common Questions

Can you take L-arginine with Testosterone Enanthate?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the L-arginine and Testosterone Enanthate interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Testosterone Enanthate and L-arginine?

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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.