Drug & supplement interaction

Fulvic Acid + Testosterone Undecanoate

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

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

Fulvic Acid has a moderate interaction with Testosterone Undecanoate. Theoretically, taking fulvic acid with thyroid hormone therapy might interfere with the ability to normalize thyroid function.

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

Fulvic Acid and Testosterone Undecanoate

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

Moderate

THYROID HORMONE

Why this applies to Testosterone Undecanoate

Testosterone Undecanoate falls under THYROID HORMONE — the group Fulvic Acid interacts with.

Theoretically, taking fulvic acid with thyroid hormone therapy might interfere with the ability to normalize thyroid function.
Animal research shows that fulvic acid increases the plasma level of thyroid-stimulating hormone (TSH) and decreases the thyroxine (T4):triiodothyronine (T3) ratio.
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

I want to be upfront with you here: the interaction sitting in our database is really about thyroid hormone medications, not testosterone. Testosterone undecanoate is a male hormone replacement, so it works through a completely different pathway than your thyroid. The signal we have (fulvic acid nudging TSH up and shifting the T4 to T3 balance) comes only from animal studies, and it simply doesn't map onto how testosterone behaves in the body.

Because of that, I don't have a real, established interaction to report between fulvic acid and your testosterone therapy. That said, human safety data on fulvic acid is thin overall. Before adding it, run it past your pharmacist or doctor so they can look at your full medication list and lab work.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Vucskits, AV, Hullar, I, Bersenyi, A, Andrasofszky, E, Kulcsar, M, Szabo, J. Effect of fulvic and humic acids on performance, immune response and thyroid function in rats. J Anim Physiol Anim Nutr (Berl) 2010;94(6):721-728. 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

Fulvic Acid Also Interacts With Other Medications

Fulvic Acid has 256 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 256 No known interaction 2,574 (incl. Testosterone Undecanoate)
Taking anything else?

Check Another of Your Medications Against Fulvic Acid

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

From our Q&A

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

We hold 294 real supplement products containing Fulvic Acid, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fulvic Acid. Your product may carry other ingredients that interact with Testosterone Undecanoate too, on top of Fulvic Acid — 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 Fulvic Acid 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 Fulvic Acid
Top half

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

29 days ago today
Medication Testosterone Undecanoate
Top 25%

#462 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 Fulvic Acid

What is Fulvic Acid?

  • General wellness and energy
  • Gut health
  • Antioxidant support
  • Mineral and nutrient supplementation
  • Immune support

Fulvic acid is a natural compound formed when plants and microbes break down in soil, and it is sold as a supplement for energy, gut, and overall wellness. Human research is very limited, so most claims are unproven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding due to a lack of safety data.

Read the full Fulvic Acid 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 & Fulvic Acid

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

0Major
256Moderate
0Minor
2,573No known interaction
256 Moderate 2,573 No interaction
Moderate

256 interactions

Showing 60 of 256 moderate interactions — see all 256 on the Fulvic Acid page.

No interaction 2,573 drugs checked — show the list

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

Showing the 60 most looked-up of 2,573 medications checked with no known interaction — see the full Fulvic Acid list.

See the full Fulvic Acid 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
Fulvic Acid 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 Fulvic Acid and Testosterone Undecanoate Together: Common Questions

Can you take Fulvic Acid 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 Fulvic Acid 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 Fulvic Acid?

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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.