Drug & supplement interaction

Hawthorn + Dalteparin

Dalteparin brand name: Fragmin.

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

Hawthorn has a moderate interaction with Dalteparin. Theoretically, hawthorn may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

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

Hawthorn and Dalteparin

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Dalteparin

Dalteparin falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Hawthorn interacts with.

Theoretically, hawthorn may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro and animal research shows that hawthorn can inhibit platelet aggregation. However, its effect in humans is unclear. One observational study shows that patients taking hawthorn shortly before undergoing coronary artery bypass graft (CABG) surgery or valve replacement surgery have a 10% incidence of postoperative bleeding, compared with 1% in those who never consumed hawthorn extract. However, clinical research shows that taking a specific preparation of dried hawthorn leaves and flowers (Crataesor, Soria Natural Lab) 800 mg three times daily for 15 days does not affect platelet aggregation or levels of thromboxane B2, the metabolite of thromboxane A2, in healthy humans.
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 gist of pairing hawthorn with dalteparin (Fragmin). Dalteparin is an injectable blood thinner, so its whole job is to lower your blood's ability to clot. Hawthorn, on paper, may have a mild blood-thinning effect of its own by making platelets a little less sticky. Stack the two and the worry is simply additive: a slightly higher chance of bleeding or bruising.

I'll be honest with you, though, this concern is theoretical. It comes mostly from lab and animal studies, and human results are mixed. Still, with a real blood thinner like dalteparin I'd play it safe. Watch for easy bruising, nosebleeds, bleeding gums, or any unusual bleeding, and check with your pharmacist or doctor before adding hawthorn.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Dalli, E., Valles, J., Cosin-Sales, J., Santos, M. T., Moscardo, A., Milara, J., and Sotillo, J. F. Effects of hawthorn (Crataegus laevigata) on platelet aggregation in healthy volunteers. Thromb.Res 2011;128(4):398-400. PubMed
  2. Rababa'h AM, Altarabsheh SE, Haddad O, Deo SV, Obeidat Y, Al-Azzam S. Hawthorn Herb Increases the Risk of Bleeding after Cardiac Surgery: An Evidence-Based Approach. Heart Surg Forum 2016;19(4):E175-9. PubMed
  3. Shatoor AS, Soliman H, Al-Hashem F, Gamal BE, Othman A, El-Menshaw N. Effect of hawthorn (Crataegus aronia syn. Azarolus (L)) on platelet function in albino wistar rats. Thromb Res 2012;130(1):75-80. PubMed
  4. Vibes J, Lasserre B, Gleye J, Declume C. Inhibition of thromboxane A2 biosynthesis in vitro by the main components of Crataegus oxyacantha (hawthorn) flower heads. Prostaglandins Leukot Essent Fatty Acids 1994;50(4):173-5. PubMed
  5. Rogers KL, Grice ID, Griffiths LR. Inhibition of platelet aggregation and 5-HT release by extracts of Australian plants used traditionally as headache treatments. Eur J Pharm Sci 2000;9(4):355-63. PubMed
  6. Zhou CC, Huang XX, Gao PY, et al. Two new compounds from Crataegus pinnatifida and their antithrombotic activities. J Asian Nat Prod Res 2014;16(2):169-74.

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

Hawthorn Also Interacts With Other Medications

Hawthorn has 14 major, 176 moderate known drug interactions in our database — the Dalteparin one above is one of them. If you take anything else, check it against the full list below.

Major 14 Moderate 176 No known interaction 2,640 (incl. Dalteparin)
Taking anything else?

Check Another of Your Medications Against Hawthorn

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

From our Q&A

Questions About Hawthorn or Dalteparin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Hawthorn or Dalteparin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Dalteparin

This page covers Hawthorn only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dalteparin page lists 218 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Piracetam (major), Aconite (moderate) and Allspice (moderate).

By severity: 3 major · 190 moderate · 25 minor.

From our pharmacist’s overview on the Dalteparin page

“Dalteparin (Fragmin) is an injectable blood thinner used to prevent and treat dangerous clots, which is exactly why this list warrants real vigilance, and nearly all 218 ingredients on it thin the blood too. They are herbs and extracts with clot-inhibiting or antiplatelet effects of their own, so stacking them on dalteparin can push bl…”

Reviewed by 2 · Jul 18, 2026

Open the Dalteparin interaction page

One more smart check

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

We hold 2,624 real supplement products containing Hawthorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hawthorn. Your product may carry other ingredients that interact with Dalteparin too, on top of Hawthorn — 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 Hawthorn and Dalteparin 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 Hawthorn
Top 10%

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

29 days ago today
Medication Dalteparin
Top half

#872 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 Hawthorn

What is Hawthorn?

Hawthorn
  • Heart failure symptoms
  • High blood pressure
  • Chest pain (angina)
  • Irregular heartbeat
  • Digestive upset
  • Anxiety

Hawthorn is a plant traditionally used for heart-related complaints, and some studies suggest it may modestly help symptoms of mild heart failure when added to standard care. However, the evidence is mixed and it should never replace prescribed heart medicines. Always talk to your pharmacist or doctor before using hawthorn, especially if you have a heart condition.

Read the full Hawthorn monograph & all interactions
Medication

About Dalteparin Injection

What Is Dalteparin Injection Used For?

Brand name: Fragmin

Fragmin (dalteparin) injection is used to prevent blood clots (deep vein thrombosis, or DVT) in people having hip replacement or abdominal surgery, and in hospitalized patients who are largely immobile due to acute illness. It is also used to reduce ischemic complications — meaning clot-related events — in people with unstable angina or a type of heart attack called non-Q-wave MI, when given alongside aspirin.

Fragmin is approved for the extended treatment of symptomatic venous thromboembolism (VTE — blood clots in the veins or lungs) in adults with cancer, to reduce the chance of clots coming back, for up to six months. It is also approved to treat symptomatic VTE in pediatric patients from birth (at least 35 weeks gestational age) onward. Fragmin is not intended for the acute (immediate emergency) treatment of VTE.

See full Dalteparin Injection drug information
Keep checking

Other Drugs & Hawthorn

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

14Major
176Moderate
0Minor
2,639No known interaction
14 Major 176 Moderate 2,639 No interaction
Major

14 interactions

Moderate

176 interactions

Showing 60 of 176 moderate interactions — see all 176 on the Hawthorn page.

No interaction 2,639 drugs checked — show the list

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

Showing the 60 most looked-up of 2,639 medications checked with no known interaction — see the full Hawthorn list.

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

Can you take Hawthorn with Dalteparin?
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 Hawthorn and Dalteparin 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 Dalteparin and Hawthorn?

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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.