Drug & supplement interaction

Dhea + Lapatinib

Lapatinib brand name: Tykerb.

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

Dhea has a moderate interaction with Lapatinib. Theoretically, DHEA might increase the levels of drugs metabolized by CYP3A4.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Dhea and Lapatinib

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Lapatinib

Lapatinib falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Dhea interacts with.

Theoretically, DHEA might increase the levels of drugs metabolized by CYP3A4.
Some preliminary evidence shows that DHEA may inhibit CYP3A4; however, the clinical significance of this potential interaction is not known.
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 basic idea with these two together. Lapatinib (Tykerb) is cleared from your body mainly by a liver enzyme called CYP3A4. There's some early, fairly weak evidence that DHEA may slow that same enzyme down. If it does, your body could clear lapatinib a bit more slowly, letting levels creep up. In real terms that might mean more of lapatinib's usual side effects, things like diarrhea, nausea, rash, fatigue, or changes in heart or liver tests.

I want to be honest that this is mostly theoretical and based on scattered reports, so the actual risk is unclear. Still, lapatinib is a serious cancer medicine, and DHEA is a true hormone that can act on hormone-sensitive breast tissue. Please don't start or stop anything on your own. Loop in your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Frye RF, Kroboth PD, Folan MM, et al. Effect of DHEA on CYP3A-mediated metabolism of triazolam. Clin Pharmacol Ther 2000;67:109 (abstract PI-82).

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

Dhea Also Interacts With Other Medications

Dhea has 767 moderate, 8 minor known drug interactions in our database — the Lapatinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 767 Minor 8 No known interaction 2,055 (incl. Lapatinib)
Taking anything else?

Check Another of Your Medications Against Dhea

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

Everything else you take

See Every Supplement That Interacts With Lapatinib

This page covers Dhea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lapatinib page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Lapatinib page

“Of the 143 supplements on file for lapatinib (Tykerb), nearly all press on the same point, the CYP3A4 enzyme that clears this HER2-targeted breast cancer drug. That deserves real caution, since lapatinib only works when its blood level stays in range.”

Reviewed by 2 · Jul 18, 2026

Open the Lapatinib interaction page

One more smart check

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

We hold 945 real supplement products containing Dhea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dhea. Your product may carry other ingredients that interact with Lapatinib too, on top of Dhea — 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 Dhea and Lapatinib 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 Dhea
Top 25%

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

29 days ago today
Medication Lapatinib
Steady interest

#2,416 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 Dhea

What is Dhea?

Dhea
  • Anti-aging and low DHEA levels
  • Mood and depression
  • Vaginal dryness and sexual health
  • Fertility support
  • Muscle mass and athletic performance
  • Adrenal insufficiency

DHEA is a natural hormone that the body makes and that declines with age, and it is sold as a supplement claiming many benefits. The evidence is mixed and limited for most uses, and because it acts as a hormone it can cause real side effects. Talk to a pharmacist or doctor before using it, especially if you have a hormone-sensitive condition.

Read the full Dhea monograph & all interactions
Medication

About Lapatinib

What Is Lapatinib Used For?

Brand name: Tykerb

Lapatinib tablets — sold under the brand name Tykerb — are used to treat advanced or metastatic breast cancer in patients whose tumors overexpress the HER2 protein. They are always used in combination with another medicine, not alone.

Tykerb is approved in combination with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior treatment including an anthracycline, a taxane, and trastuzumab, and whose disease has progressed on trastuzumab. Tykerb is also approved in combination with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate.

See full Lapatinib drug information
Keep checking

Other Drugs & Dhea

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

0Major
767Moderate
8Minor
2,054No known interaction
767 Moderate 8 Minor 2,054 No interaction
Moderate

767 interactions

Showing 60 of 767 moderate interactions — see all 767 on the Dhea page.

Minor

8 interactions

No interaction 2,054 drugs checked — show the list

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

Showing the 60 most looked-up of 2,054 medications checked with no known interaction — see the full Dhea list.

See the full Dhea interactions page
See every supplement checked against Lapatinib, 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
Dhea monograph › Uses, safety, and every drug interaction in one place Lapatinib supplement interactions › Every supplement checked against Lapatinib, ranked by severity Lapatinib 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 Dhea and Lapatinib Together: Common Questions

Can you take Dhea with Lapatinib?
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 Dhea and Lapatinib 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 Lapatinib and Dhea?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.