Drug & supplement interaction

Citric Acid + Erlotinib

Erlotinib brand name: Tarceva.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 27, 2026
The bottom line No known interaction

We found no known interaction between Citric Acid and Erlotinib 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 label for Erlotinib states a food rule worth keeping to, and 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

Citric Acid and Erlotinib

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 Erlotinib and Citric 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 Citric Acid at all — not against Erlotinib, 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.

Citric Acid safety at a glance

Citric Acid overall Generally safe Generally recognized as safe in the small amounts found in foods and most supplements.
Pregnancy Likely Safe When citric acid is used orally in the amounts commonly found in foods. There is insufficient reliable information available about the safety of citric acid whe... Read the full pregnancy detail
Breastfeeding Likely Safe When citric acid is used orally in the amounts commonly found in foods. There is insufficient reliable information available about the safety of citric acid whe... 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 Erlotinib and Citric Acid? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Citric Acid and Erlotinib 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. One of them is worth acting on rather than waiting out — marked below.

  • Bleeding or bruising Worth acting on Additional detail

    Citric Acid

    “Topically, citric acid seems to be well tolerated when used as part of formulations containing the alpha hydroxy acids glycolic acid and lactic acid in concentrations at or below 10% and applied to the face. In general, products should be tested on a small area of skin before applying it to a larger area.

    Alpha hydroxy acids like citric acid can increase sensitivity to the sun and ultraviolet (UV) light.”

    Citric Acid · Natural Medicines adverse-effect record, reported in burns.

    6 sources cited
    1. 106612. US Food and Drug Administration (FDA). Cosmetic Ingredients: Alpha Hydroxy Acids. August 2020. Available at: https://www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids. Accessed on October 19, 2021.
    2. 6080. Kurtzweil P. Alpha-hydroxy acids for skin care: Smooth sailing or rough seas? FDA 1999. Available at: /www.fda.gov/fdac/features/1998/298_ahas.html (Accessed 18 August 2000). DOI
    3. 10101. Erbagci Z, Akcali C. Biweekly serial glycolic acid peels vs. long-term daily use of topical low-strength glycolic acid in the treatment of atrophic acne scars. Int J Dermatol 2000;39:789-94.. PubMed
    4. 92209. Baumann LS, Oresajo C, Yatskayer M, Dahl A, Figueras K. Comparison of clindamycin 1% and benzoyl peroxide 5% gel to a novel composition containing salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid in the treatment
    5. 92210. Emtestam L, Svensson Å, Rensfeldt K. Treatment of seborrhoeic dermatitis of the scalp with a topical solution of urea, lactic acid, and propylene glycol (K301): results of two double-blind, randomised, placebo-controlled studies. Mycoses. 2012 Sep;55(5):3 PubMed
    6. 92214. Kaminaka C, Uede M, Matsunaka H, Furukawa F, Yamomoto Y. Clinical evaluation of glycolic acid chemical peeling in patients with acne vulgaris: a randomized, double-blind, placebo-controlled, split-face comparative study. Dermatol Surg. 2014 Mar;40(3):314- PubMed

    Erlotinib

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

  • Sun sensitivity Additional detail

    Citric Acid

    Recorded for Citric Acid in the same Natural Medicines adverse-effect record shown under Bleeding or bruising above.

    Erlotinib

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

  • A skin rash reported in 10.6% of FDA reports for Erlotinib Additional detail

    Citric Acid

    Recorded for Citric Acid in the same Natural Medicines adverse-effect record shown under Bleeding or bruising above.

    Erlotinib

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

  • Itching Additional detail

    Citric Acid

    Recorded for Citric Acid in the same Natural Medicines adverse-effect record shown under Bleeding or bruising above.

    Erlotinib

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

Reported for Citric Acid but not commonly for Erlotinib: numbness or tingling and swelling.

Effects for Erlotinib come from the ADVERSE REACTIONS section of its FDA label; effects for Citric Acid come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 12,442 voluntary FDA FAERS reports for Erlotinib 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

Citric Acid in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When citric acid is used orally in the amounts commonly found in foods. There is insufficient reliable information available about the safety of citric acid when used orally in larger amounts during pregnancy or lactation; avoid amounts greater than those found in foods.

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

How to take them

Some Erlotinib Products Have a Food Rule — Citric Acid Should Not Break It

At least one FDA label for a product containing Erlotinib says to take it on an empty stomach. Most supplements — Citric Acid included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Erlotinib on its own and move Citric Acid to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Erlotinib products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Recommended Dose – NSCLC The recommended daily dose of erlotinib tablets for NSCLC is 150 mg taken on an empty stomach, i.e., at least one hour before or two hours after the ingestion of food.

From the Dosage and Administration section of the FDA label we read for Erlotinib — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Erlotinib

This page covers Citric Acid only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Erlotinib page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Bilberry (moderate), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Erlotinib page

“Activated charcoal is the entry I would flag first for anyone taking erlotinib (Tarceva), an oral targeted therapy for certain lung cancers. Charcoal can adsorb the drug in the gut and cut how much reaches the bloodstream, and with a cancer pill, less absorbed means less cancer fought.”

Reviewed by 2 · Jul 18, 2026

Open the Erlotinib interaction page

One more smart check

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

We hold 331 real supplement products containing Citric Acid, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Citric Acid. Even though Citric Acid itself has no known interaction with Erlotinib, 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 Citric Acid and Erlotinib 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 Citric Acid
Top 25%

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

29 days ago today
Medication Erlotinib
Steady interest

#1,637 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 Citric Acid reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Citric Acid and Erlotinib records this page draws on were last updated July 10, 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 Citric Acid

What is Citric Acid?

  • Food and drink flavoring or sourness
  • Preservative and acidity adjuster
  • Kidney stone prevention (as citrate salts)
  • Cleaning and descaling (non-medical)
  • Effervescent supplement and antacid blends

Citric acid is a natural acid found in citrus fruits and is widely used as a safe food additive, flavoring, and preservative. In medicine, citrate forms (like potassium or sodium citrate) are used to help prevent certain kidney stones and to make urine less acidic. For most people the small amounts in foods and supplements are safe, but concentrated products can irritate the mouth, stomach, and skin.

Naturally found in citrus fruits; commercially made by fermentation · Powder, crystals, liquid, effervescent tablets, and as an ingredient in foods, drinks, and supplements

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

Citric Acid: dosing

There is no standard supplement dose of plain citric acid, because it is mainly used as a food ingredient rather than a treatment. Amounts used in foods and drinks are small and considered safe.For medicinal citrate products (such as potassium citrate or sodium citrate used for kidney stones or urine alkalinization), dosing is individualized and should be set by a doctor, often based on lab tests.

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

Read the full Citric Acid monograph & all interactions
Medication

About Erlotinib

What Is Erlotinib Used For?

Brand name: Tarceva

Erlotinib tablets are used to treat metastatic non-small cell lung cancer (NSCLC) in patients whose tumors carry specific gene changes — EGFR exon 19 deletions or exon 21 (L858R) mutations — confirmed by an FDA-approved test. It can be used as a first-line treatment, as maintenance therapy, or after at least one prior chemotherapy has stopped working.

Erlotinib tablets are also used for the first-line treatment of locally advanced, unresectable, or metastatic pancreatic cancer — but only in combination with another chemotherapy drug called gemcitabine. Erlotinib is not recommended alongside platinum-based chemotherapy regimens.

Most-Reported Side Effects for Erlotinib

From FAERS, the FDA’s public side-effect reporting system (12,441 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 1,339 reports
Rash 1,317 reports
Malignant neoplasm progression 890 reports
Fatigue 718 reports
Nausea 696 reports
See full Erlotinib drug information
Keep checking

Other Drugs & Citric Acid

Browse every other medication we’ve checked against Citric 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 Citric 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 Citric Acid list.

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

Citric Acid References

The 10 references that drive our Citric 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. Kurtzweil P. Alpha-hydroxy acids for skin care: Smooth sailing or rough seas? FDA 1999. Available at: /www.fda.gov/fdac/features/1998/298_ahas.html (Accessed 18 August 2000). DOI
  2. Erbagci Z, Akcali C. Biweekly serial glycolic acid peels vs. long-term daily use of topical low-strength glycolic acid in the treatment of atrophic acne scars. Int J Dermatol 2000;39:789-94.. PubMed
  3. Ghadishah D, Gorchynski J. Airway compromise after routine alpha-hydroxy facial peel administration. J Emerg Med 2002;22:353-5.. PubMed
  4. Baumann LS, Oresajo C, Yatskayer M, Dahl A, Figueras K. Comparison of clindamycin 1% and benzoyl peroxide 5% gel to a novel composition containing salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid in the treatment
  5. Emtestam L, Svensson Å, Rensfeldt K. Treatment of seborrhoeic dermatitis of the scalp with a topical solution of urea, lactic acid, and propylene glycol (K301): results of two double-blind, randomised, placebo-controlled studies. Mycoses. 2012 Sep;55(5):3 PubMed
  6. Kaminaka C, Uede M, Matsunaka H, Furukawa F, Yamomoto Y. Clinical evaluation of glycolic acid chemical peeling in patients with acne vulgaris: a randomized, double-blind, placebo-controlled, split-face comparative study. Dermatol Surg. 2014 Mar;40(3):314- PubMed
  7. Köse O, Özmen I, Arca E. An open, comparative study of 10% potassium hydroxide solution versus salicylic and lactic acid combination in the treatment of molluscum contagiosum in children. J Dermatolog Treat. 2013 Aug;24(4):300-4. PubMed
  8. Vachiramon V, Sahawatwong S, Sirithanabadeekul P. Treatment of melasma in men with low-fluence Q-switched neodymium-doped yttrium-aluminum-garnet laser versus combined laser and glycolic acid peeling. Dermatol Surg. 2015 Apr;41(4):457-65. PubMed
  9. US Food and Drug Administration (FDA). Cosmetic Ingredients: Alpha Hydroxy Acids. August 2020. Available at: https://www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids. Accessed on October 19, 2021.
  10. Ormerod AD, van Voorst Vader PC, Majewski S, Vanscheidt W, Benjamin N, van der Meijden W. Evaluation of the efficacy, safety, and tolerability of 3 dose regimens of topical sodium nitrite with citric acid in patients with anogenital warts: A randomized cl DOI

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 Citric Acid and Erlotinib Together: Common Questions

Is it safe to take Citric Acid with Erlotinib?
We do not list a known interaction between Citric Acid and Erlotinib. 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 Citric Acid and Erlotinib have any of the same side effects?
Yes — our sources link each of them separately to 4 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.
Should I take Citric Acid and Erlotinib at the same time of day?
At least one FDA label for a product containing Erlotinib says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Erlotinib on its own and move Citric Acid to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Does Erlotinib interact with any supplements?
Yes. Erlotinib has documented interactions with 18 supplements in our database — Citric Acid is not one of them. The Erlotinib interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Citric Acid monograph Uses, safety profile, and every drug interaction in one place Erlotinib drug information The full plain-English guide to this medication Erlotinib supplement interactions Every supplement checked against Erlotinib, 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Erlotinib and Citric 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.