Drug & supplement interaction

Pregnenolone + Testosterone Undecanoate

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

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

Pregnenolone has a moderate interaction with Testosterone Undecanoate. Theoretically, taking pregnenolone might enhance the effects of testosterone.

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

Pregnenolone and Testosterone Undecanoate

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

Moderate

TESTOSTERONE

Theoretically, taking pregnenolone might enhance the effects of testosterone.
Pregnenolone is a precursor for several steroid hormones, including testosterone. However, preliminary clinical research shows that taking pregnenolone 30-500 mg orally daily for up to 8 weeks does not affect testosterone levels.
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 thinking behind this pairing. Pregnenolone is a hormone your body uses early in the chain that eventually makes testosterone, so on paper there's a worry that adding it on top of your testosterone undecanoate could pile on more hormonal effect. If that happened, you might in theory see more of the usual testosterone side effects, things like acne, oily skin, mood swings, fluid retention, or a higher red blood cell count.

The reassuring part is that this is only a theoretical concern based on how these hormones are related. In small human studies, pregnenolone taken by mouth (30 to 500 mg daily for up to 8 weeks) didn't actually raise testosterone levels. Still, since both are hormones, I'd run it past your doctor or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Devlin TM, ed. Textbook of Biochemistry With Clinical Correlations. third ed. New York: Wiley-Liss Inc., 1992.
  2. Ritsner MS, Gibel A, Shleifer T, et al. Pregnenolone and dehydroepiandrosterone as an adjunctive treatment in schizophrenia and schizoaffective disorder: an 8-week, double-blind, randomized, controlled, 2-center, parallel-group trial. J Clin Psychiatry 20 PubMed
  3. Marx CE, Keefe RS, Buchanan RW, et al. Proof-of-concept trial with the neurosteroid pregnenolone targeting cognitive and negative symptoms in schizophrenia. Neuropsychopharmacology 2009;34(8):1885-903. 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

Pregnenolone Also Interacts With Other Medications

Pregnenolone has 81 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.

Moderate 81 No known interaction 2,749 (incl. Testosterone Undecanoate)
Taking anything else?

Check Another of Your Medications Against Pregnenolone

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

From our Q&A

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

We hold 303 real supplement products containing Pregnenolone, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pregnenolone. Your product may carry other ingredients that interact with Testosterone Undecanoate too, on top of Pregnenolone — 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 Pregnenolone 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 Pregnenolone
Top 25%

#321 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 Pregnenolone

What is Pregnenolone?

Pregnenolone
  • Memory and cognitive support
  • Anxiety and stress
  • Anti-aging
  • Fatigue and low energy
  • Mood support

Pregnenolone is a hormone your body makes naturally and a building block for other hormones like cortisol, DHEA, estrogen, and testosterone. It is sold as a supplement for memory, mood, and anti-aging, but solid human evidence for these uses is very limited. Because it is a hormone, talk with your pharmacist or doctor before using it.

Read the full Pregnenolone 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 & Pregnenolone

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

0Major
81Moderate
0Minor
2,748No known interaction
81 Moderate 2,748 No interaction
Moderate

81 interactions

Showing 60 of 81 moderate interactions — see all 81 on the Pregnenolone page.

No interaction 2,748 drugs checked — show the list

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

Showing the 60 most looked-up of 2,748 medications checked with no known interaction — see the full Pregnenolone list.

See the full Pregnenolone interactions page
See every supplement checked against Testosterone Undecanoate, 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
Pregnenolone monograph › Uses, safety, and every drug interaction in one place Testosterone Undecanoate supplement interactions › Every supplement checked against Testosterone Undecanoate, 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 Pregnenolone and Testosterone Undecanoate Together: Common Questions

Can you take Pregnenolone 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 Pregnenolone 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 Pregnenolone?

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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.