Drug & supplement interaction

Betaine Anhydrous + Lapatinib

Lapatinib brand name: Tykerb.

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 Betaine Anhydrous and Lapatinib 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

Betaine Anhydrous and Lapatinib

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 Lapatinib and Betaine Anhydrous 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 Betaine Anhydrous at all — not against Lapatinib, 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.

Betaine Anhydrous safety at a glance

Betaine Anhydrous overall Use caution Generally well tolerated in studied doses, but check with a healthcare provider before use.
Pregnancy Use caution There is not enough reliable safety data, so it is best to avoid unless a doctor advises otherwise.
Breastfeeding Use caution Safety while breastfeeding is not well established, so caution is advised.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Lapatinib and Betaine Anhydrous? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Betaine Anhydrous and Lapatinib 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 / Vomiting / Nausea reported in 27.1% of FDA reports for Lapatinib Additional detail

    Betaine Anhydrous

    “Orally, betaine anhydrous can cause vomiting, nausea, GI distress, and diarrhea.”

    Betaine Anhydrous · Natural Medicines adverse-effect record, reported in diarrhea.

    5 sources cited
    1. 698. Cystadane (betaine anhydrous for oral solution) Package insert. Orphan Medical, Inc. Minnetonka, MN. November 2005.
    2. 10631. Abdelmalek MF, Angulo P, Jorgensen RA, et al. Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study. Am J Gastroenterol 2001;96:2711-7.. PubMed
    3. 34888. Knopman, D. and Patterson, M. An open-label, 24-week pilot study of the methyl donor betaine in Alzheimer disease patients. Alzheimer Dis.Assoc.Disord. 2001;15(3):162-165. PubMed
    4. 34928. Abdelmalek, M. F., Sanderson, S. O., Angulo, P., Soldevila-Pico, C., Liu, C., Peter, J., Keach, J., Cave, M., Chen, T., McClain, C. J., and Lindor, K. D. Betaine for nonalcoholic fatty liver disease: results of a randomized placebo-controlled trial. Hepa PubMed
    5. 111374. Imbard A, Toumazi A, Magréault S, et al. Efficacy and pharmacokinetics of betaine in CBS and cblC deficiencies: a cross-over randomized controlled trial. Orphanet J Rare Dis 2022;17(1):417. PubMed

    Lapatinib

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

Reported for Betaine Anhydrous but not commonly for Lapatinib: swelling.

Effects for Lapatinib come from the ADVERSE REACTIONS section of its FDA label; effects for Betaine Anhydrous come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 15,427 voluntary FDA FAERS reports for Lapatinib 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.

Everything else you take

See Every Supplement That Interacts With Lapatinib

This page covers Betaine Anhydrous 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 Betaine Anhydrous as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,564 real supplement products containing Betaine Anhydrous, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Betaine Anhydrous. Even though Betaine Anhydrous itself has no known interaction with Lapatinib, 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 Betaine Anhydrous 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 Betaine Anhydrous
Top 25%

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

29 days ago today
Medication Lapatinib
Steady interest

#2,776 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 Betaine Anhydrous reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Betaine Anhydrous and Lapatinib 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 Betaine Anhydrous

What is Betaine Anhydrous?

  • High homocysteine levels
  • Liver health (fatty liver)
  • Exercise performance and strength
  • Digestive support (as betaine HCl, a related form)
  • General supplementation in sports nutrition

Betaine anhydrous (also called trimethylglycine) is a compound found in foods like beets, spinach, and whole grains, and is sold as a supplement and as a prescription medicine for a rare genetic condition. It is best supported for lowering homocysteine and is studied for exercise performance, though those results are mixed. Talk to your pharmacist or doctor before starting it, especially if you are pregnant, breastfeeding, or have a medical condition.

Betaine is a naturally occurring compound; the supplement form is typically derived from sugar beets (Beta vulgaris) or made synthetically · Powder, capsules, tablets; also a prescription form (betaine anhydrous) for a specific genetic disorder

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

Betaine Anhydrous: dosing

There is no single standardized dose for betaine anhydrous as a general supplement. Do not assume more is better, since higher doses may increase side effects.

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

Read the full Betaine Anhydrous monograph & all interactions
Medication

About Lapatinib

What Is Lapatinib Used For?

Brand name: Tykerb

Lapatinib tablets are used in combination with other medicines to treat certain types of advanced or metastatic breast cancer in patients whose tumors overexpress HER2 (a protein that drives tumor growth). It is not used alone.

Specifically, lapatinib tablets are used with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior therapy (including certain chemotherapy drugs and trastuzumab). Lapatinib tablets are also used with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate. Tykerb is the brand name product with these same indicated uses.

Most-Reported Side Effects for Lapatinib

From FAERS, the FDA’s public side-effect reporting system (15,427 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 4,174 reports
Nausea 1,615 reports
Fatigue 1,305 reports
Vomiting 1,209 reports
Rash 1,061 reports
See full Lapatinib drug information
Keep checking

Other Drugs & Betaine Anhydrous

Browse every other medication we’ve checked against Betaine Anhydrous — 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 Betaine Anhydrous 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 Betaine Anhydrous list.

See the full Betaine Anhydrous interactions page
See every supplement checked against Lapatinib, ranked by severity
Evidence & sources

Betaine Anhydrous References

The 11 references that drive our Betaine Anhydrous 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. Cystadane (betaine anhydrous for oral solution) Package insert. Orphan Medical, Inc. Minnetonka, MN. November 2005.
  2. Abdelmalek MF, Angulo P, Jorgensen RA, et al. Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study. Am J Gastroenterol 2001;96:2711-7.. PubMed
  3. Schwab U, Torronen A, Toppinen L, et al. Betaine supplementation decreases plasma homocysteine concentrations but does not affect body weight, body composition, or resting energy expenditure in human subjects. Am J Clin Nutr 2002;76:961-7. PubMed
  4. McGregor DO, Dellow WJ, Robson RA, et al. Betaine supplementation decreases post-methionine hyperhomocysteinemia in chronic renal failure. Kidney Int 2002;61:1040-6. PubMed
  5. Olthof MR, van Vliet T, Verhoef P, et al. Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans. PloS Med 2005;2:e135. PubMed
  6. Knopman, D. and Patterson, M. An open-label, 24-week pilot study of the methyl donor betaine in Alzheimer disease patients. Alzheimer Dis.Assoc.Disord. 2001;15(3):162-165. PubMed
  7. Moat, S. J., Madhavan, A., Taylor, S. Y., Payne, N., Allen, R. H., Stabler, S. P., Goodfellow, J., McDowell, I. F., Lewis, M. J., and Lang, D. High- but not low-dose folic acid improves endothelial function in coronary artery disease. Eur J Clin Invest 2 PubMed
  8. Abdelmalek, M. F., Sanderson, S. O., Angulo, P., Soldevila-Pico, C., Liu, C., Peter, J., Keach, J., Cave, M., Chen, T., McClain, C. J., and Lindor, K. D. Betaine for nonalcoholic fatty liver disease: results of a randomized placebo-controlled trial. Hepa PubMed
  9. Ashtary-Larky D, Bagheri R, Ghanavati M, et al. Effects of betaine supplementation on cardiovascular markers: a systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2021 Mar 25:1-18. PubMed
  10. Zawieja EE, Zawieja B, Chmurzynska A. Betaine supplementation moderately increases total cholesterol levels: a systematic review and meta-analysis. J Diet Suppl. 2021;18(1):105-117. PubMed
  11. Imbard A, Toumazi A, Magréault S, et al. Efficacy and pharmacokinetics of betaine in CBS and cblC deficiencies: a cross-over randomized controlled trial. Orphanet J Rare Dis 2022;17(1):417. 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 Betaine Anhydrous and Lapatinib Together: Common Questions

Is it safe to take Betaine Anhydrous with Lapatinib?
We do not list a known interaction between Betaine Anhydrous and Lapatinib. 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 Betaine Anhydrous and Lapatinib 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.
Does Lapatinib interact with any supplements?
Yes. Lapatinib has documented interactions with 143 supplements in our database — Betaine Anhydrous is not one of them. The Lapatinib 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

Betaine Anhydrous monograph Uses, safety profile, and every drug interaction in one place Lapatinib drug information The full plain-English guide to this medication Lapatinib supplement interactions Every supplement checked against Lapatinib, 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 Lapatinib and Betaine Anhydrous?

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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.