Drug & supplement interaction

Deer Velvet + Esterified Estrogens, Methyltestosterone

Esterified Estrogens, Methyltestosterone brand name: Estratest.

Minor Interaction
The bottom line Minor

Deer Velvet has a minor interaction with Esterified Estrogens, Methyltestosterone. Theoretically, deer velvet might increase the effects and side effects of estrogens.

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

Deer Velvet and Esterified Estrogens, Methyltestosterone

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

Minor

ESTROGENS

Why this applies to Esterified Estrogens, Methyltestosterone

Esterified Estrogens, Methyltestosterone falls under ESTROGENS — the group Deer Velvet interacts with.

Theoretically, deer velvet might increase the effects and side effects of estrogens.
Laboratory evidence shows that deer velvet contains small quantities of estradiol and testosterone. While clinical research shows that taking deer velvet extract does not raise testosterone levels, estradiol levels were not measured.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version. Estratest already gives you a steady dose of estrogen (plus a bit of testosterone). Lab testing has found that deer velvet carries tiny amounts of estradiol, which is a form of estrogen. So in theory, stacking it on top of your medicine could add a little extra estrogen activity. If that happened, you might notice the usual estrogen-related effects nudged up a bit, things like breast tenderness, bloating, nausea, or spotting.

I want to be honest about how weak this is. It is a theoretical concern based on chemistry, not real patient cases, and the amounts in deer velvet are very small. Still, since you're on a hormone product, it's worth a quick mention to your pharmacist or doctor before you start it.

References
  1. Sleivert, G., Burke, V., Palmer, C., Walmsley, A., Gerrard, D., Haines, S., and Littlejohn, R. The effects of deer antler velvet extract or powder supplementation on aerobic power, erythropoiesis, and muscular strength and endurance characteristics. Int PubMed
  2. Bubenik, G. A., Miller, K. V., Lister, A. L., Osborn, D. A., Bartos, L., and van der Kraak, G. J. Testosterone and estradiol concentrations in serum, velvet skin, and growing antler bone of male white-tailed deer. J Exp Zoolog.A Comp Exp Biol 3-1-2005;30 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

Deer Velvet Also Interacts With Other Medications

Deer Velvet has 51 minor known drug interactions in our database — the Esterified Estrogens, Methyltestosterone 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 Deer Velvet

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

Everything else you take

See Every Supplement That Interacts With Esterified Estrogens, Methyltestosterone

This page covers Deer Velvet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Esterified Estrogens, Methyltestosterone page lists 221 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 · 177 moderate · 38 minor.

From our pharmacist’s overview on the Esterified Estrogens, Methyltestosterone page

“Start with grapefruit. For anyone taking Estratest (esterified estrogens, methyltestosterone) for menopausal symptoms, grapefruit juice blocks the enzyme that clears these hormones, letting levels and side effects climb, while St.”

Reviewed by 2 · Jul 18, 2026

Open the Esterified Estrogens, Methyltestosterone interaction page

One more smart check

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

We hold 249 real supplement products containing Deer Velvet, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Deer Velvet. Your product may carry other ingredients that interact with Esterified Estrogens, Methyltestosterone too, on top of Deer Velvet — 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 Deer Velvet and Esterified Estrogens, Methyltestosterone 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 Deer Velvet
Top 25%

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

29 days ago today
Medication Esterified Estrogens, Methyltestosterone
Steady interest

#2,783 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 Deer Velvet

What is Deer Velvet?

Deer Velvet
  • Athletic performance and strength
  • Energy and fatigue
  • Joint health and arthritis
  • Immune support
  • Sexual function and libido

Deer velvet is a traditional remedy made from the soft, growing antlers of deer or elk, and it is most often promoted for energy, athletic performance, and joint health. Good-quality human evidence is limited, and most claims are not well proven. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Deer Velvet monograph & all interactions
Keep checking

Other Drugs & Deer Velvet

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

0Major
0Moderate
51Minor
2,778No known interaction
Minor

51 interactions

No interaction 2,778 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 Deer Velvet and Esterified Estrogens, Methyltestosterone Together: Common Questions

Can you take Deer Velvet with Esterified Estrogens, Methyltestosterone?
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 Deer Velvet and Esterified Estrogens, Methyltestosterone 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

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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.