Drug & supplement interaction

Pantothenic Acid + Trastuzumab

Trastuzumab brand name: Herceptin.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Pantothenic Acid and Trastuzumab in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Pantothenic Acid and Trastuzumab

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Trastuzumab and Pantothenic Acid in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Pantothenic Acid at all — not against Trastuzumab, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Pantothenic Acid safety at a glance

Pantothenic Acid overall Generally safe Considered safe for most people at typical supplement doses, with few side effects.
Pregnancy Likely Safe When used orally and appropriately. The daily adequate intake (AI) during pregnancy is 6 mg. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally and appropriately. The daily adequate intake (AI) during lactation is 7 mg. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Trastuzumab and Pantothenic Acid? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Pantothenic Acid and Trastuzumab May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea reported in 8.9% of FDA reports for Trastuzumab Additional detail

    Pantothenic Acid

    “Orally, pantothenic acid has been associated with diarrhea.”

    Pantothenic Acid · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 67822. Champault, G. and Patel, J. C. [Treatment of constipation with Bepanthene]. Med.Chir Dig. 1977;6(1):57-59.
    2. 111258. Scott LN, Fiume M, Bergfeld WF, et al. Safety Assessment of Panthenol, Pantothenic Acid, and Derivatives as Used in Cosmetics. Int J Toxicol 2022;41(3_suppl):77-128. PubMed

    Trastuzumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Trastuzumab, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Itching / A skin rash Additional detail

    Pantothenic Acid

    “Topically, dexpanthenol has been associated with itching, burning, skin irritation, contact dermatitis, and eczema. Three cases of allergic contact dermatitis have been reported.”

    Pantothenic Acid · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 67779. Schmuth, M., Wimmer, M. A., Hofer, S., Sztankay, A., Weinlich, G., Linder, D. M., Elias, P. M., Fritsch, P. O., and Fritsch, E. Topical corticosteroid therapy for acute radiation dermatitis: a prospective, randomized, double-blind study. Br.J.Dermatol. 2 PubMed
    2. 67781. Schreck, U., Paulsen, F., Bamberg, M., and Budach, W. Intraindividual comparison of two different skin care conceptions in patients undergoing radiotherapy of the head-and-neck region. Creme or powder? Strahlenther.Onkol. 2002;178(6):321-329. PubMed
    3. 67788. Herbst, R. A., Uter, W., Pirker, C., Geier, J., and Frosch, P. J. Allergic and non-allergic periorbital dermatitis: patch test results of the Information Network of the Departments of Dermatology during a 5-year period. Contact Dermatitis 2004;51(1):13-1 PubMed
    4. 111258. Scott LN, Fiume M, Bergfeld WF, et al. Safety Assessment of Panthenol, Pantothenic Acid, and Derivatives as Used in Cosmetics. Int J Toxicol 2022;41(3_suppl):77-128. PubMed
    5. 111262. Peltier E, Trapp S, de Salvo R, et al. A new dexpanthenol-containing liquid cleanser for atopic-prone skin: Results from two prospective clinical studies evaluating cutaneous tolerability, moisturization potential, and effects on barrier function. J Cosme PubMed
    6. 111260. Han J, Warshaw EM. Allergic Contact Dermatitis to Panthenol in "Hypoallergenic" Products. Dermatitis 2023;34(1):62-63. PubMed

    Trastuzumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Trastuzumab. Read the label on DailyMed ›

Effects for Trastuzumab come from the ADVERSE REACTIONS section of its FDA label; effects for Pantothenic Acid come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 86,493 voluntary FDA FAERS reports for Trastuzumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Pantothenic Acid in Pregnancy & Breastfeeding

Pregnancy Likely Safe

When used orally and appropriately. The daily adequate intake (AI) during pregnancy is 6 mg.

Lactation Likely Safe

When used orally and appropriately. The daily adequate intake (AI) during lactation is 7 mg.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

One more smart check

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

We hold 15,997 real supplement products containing Pantothenic Acid, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pantothenic Acid. Even though Pantothenic Acid itself has no known interaction with Trastuzumab, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Pantothenic Acid and Trastuzumab 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 Pantothenic Acid
Top 5%

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

29 days ago today
Medication Trastuzumab
Top 10%

#206 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Pantothenic Acid reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Pantothenic Acid and Trastuzumab records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Pantothenic Acid

What is Pantothenic Acid?

  • General nutrition and energy
  • Skin and hair health
  • Acne (topical and oral)
  • Wound healing (as panthenol)
  • Cholesterol support (as pantethine)

Pantothenic acid is vitamin B5, an essential nutrient your body uses to turn food into energy. True deficiency is very rare because it is found in nearly all foods, and most people meet their needs through diet. Supplements are generally considered safe, but evidence that extra amounts treat acne, high cholesterol, or other conditions is limited.

Tablets, capsules, softgels, multivitamins, topical creams (as panthenol)

An interaction check asks whether these two react with each other — it does not ask whether Pantothenic Acid is a good idea for someone in your situation. Here is what our Pantothenic Acid record says about it on its own.

Pantothenic Acid: dosing

There is no single standardized "treatment" dose of pantothenic acid for most uses. Nutrition authorities set general daily intake amounts for adults to prevent deficiency, and most people easily get this from food.Supplement products vary widely in how much they contain, with some marketed for acne or other uses providing amounts far above dietary needs. Do not assume more is better.

From our Pantothenic Acid monograph — the full record covers uses, side effects and every documented interaction.

Read the full Pantothenic Acid monograph & all interactions
Medication

About Trastuzumab Injection

What Is Trastuzumab Injection Used For?

Brand name: Herceptin

Trastuzumab injection is used in adults to treat certain cancers that overexpress the HER2 protein. For breast cancer, it is used as adjuvant (after-surgery) treatment for early-stage HER2-positive breast cancer, in combination with certain chemotherapy regimens, as well as for metastatic (spread) HER2-positive breast cancer — either with paclitaxel as a first-line treatment or as a single agent after prior chemotherapy.

Ontruzant is also indicated in adults for treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma (a type of stomach or esophageal junction cancer), in combination with cisplatin and capecitabine or 5-fluorouracil, for patients who have not received prior treatment for metastatic disease. Patients must be selected based on FDA-approved HER2 testing before starting therapy.

Most-Reported Side Effects for Trastuzumab

From FAERS, the FDA’s public side-effect reporting system (88,598 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 7,825 reports
Nausea 6,098 reports
Fatigue 5,551 reports
Alopecia 5,432 reports
Disease progression 4,960 reports
See full Trastuzumab Injection drug information
Keep checking

Other Drugs & Pantothenic Acid

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Pantothenic Acid list.

See the full Pantothenic Acid interactions page
See every supplement checked against Trastuzumab, ranked by severity
Evidence & sources

Pantothenic Acid References

The 11 references that drive our Pantothenic Acid monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Debourdeau PM, Djezzar S, Estival JL, et al. Life-threatening eosinophilic pleuropericardial effusion related to vitamins B5 and H. Ann Pharmacother 2001;35:424-6. DOI
  4. Schmuth, M., Wimmer, M. A., Hofer, S., Sztankay, A., Weinlich, G., Linder, D. M., Elias, P. M., Fritsch, P. O., and Fritsch, E. Topical corticosteroid therapy for acute radiation dermatitis: a prospective, randomized, double-blind study. Br.J.Dermatol. 2 PubMed
  5. Schreck, U., Paulsen, F., Bamberg, M., and Budach, W. Intraindividual comparison of two different skin care conceptions in patients undergoing radiotherapy of the head-and-neck region. Creme or powder? Strahlenther.Onkol. 2002;178(6):321-329. PubMed
  6. Herbst, R. A., Uter, W., Pirker, C., Geier, J., and Frosch, P. J. Allergic and non-allergic periorbital dermatitis: patch test results of the Information Network of the Departments of Dermatology during a 5-year period. Contact Dermatitis 2004;51(1):13-1 PubMed
  7. Champault, G. and Patel, J. C. [Treatment of constipation with Bepanthene]. Med.Chir Dig. 1977;6(1):57-59.
  8. Scott LN, Fiume M, Bergfeld WF, et al. Safety Assessment of Panthenol, Pantothenic Acid, and Derivatives as Used in Cosmetics. Int J Toxicol 2022;41(3_suppl):77-128. PubMed
  9. Han J, Warshaw EM. Allergic Contact Dermatitis to Panthenol in "Hypoallergenic" Products. Dermatitis 2023;34(1):62-63. PubMed
  10. Blanchard G, Kerre S, Walker A, et al. Allergic contact dermatitis from pantolactone and dexpanthenol in wound healing creams. Contact Dermatitis 2022;87(5):468-471. PubMed
  11. Peltier E, Trapp S, de Salvo R, et al. A new dexpanthenol-containing liquid cleanser for atopic-prone skin: Results from two prospective clinical studies evaluating cutaneous tolerability, moisturization potential, and effects on barrier function. J Cosme PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Pantothenic Acid and Trastuzumab Together: Common Questions

Is it safe to take Pantothenic Acid with Trastuzumab?
We do not list a known interaction between Pantothenic Acid and Trastuzumab. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Pantothenic Acid and Trastuzumab have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

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

Where next

Keep Exploring

Pantothenic Acid monograph Uses, safety profile, and every drug interaction in one place Trastuzumab Injection drug information The full plain-English guide to this medication Trastuzumab supplement interactions Every supplement checked against Trastuzumab, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 11 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Trastuzumab and Pantothenic 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.