Purported Benefits, Side Effects & More


Purported Benefits, Side Effects & More

Common Names

  • May flower
  • Shan Zha
  • Crataegus berries
  • Quickthorn
  • Whitehorn

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

Hawthorn may be helpful in some patients with heart failure. Definitive data are needed on safety and efficacy.

Derived from the flower, leaves, and fruits of the plant, hawthorn is also known in Asia as Shan Zha. It is used in traditional Chinese medicine to improve digestion and treat heart problems. Hawthorn also has a long history in European medicine as a heart tonic.

Studies in the lab suggest a range of anti-inflammation, heart-protective, and digestion-improving properties. Studies in humans show benefits in patients with congestive heart failure, although a few trials did not.

More studies are needed to confirm safety and effectiveness of hawthorn. In addition, it should not be used in place of conventional heart failure therapies and its use should be monitored by the treating physician.

What are the potential uses and benefits?
  • To improve digestion

    Hawthorn is used to relieve indigestion in traditional Chinese medicine, but clinical studies are lacking.
  • To treat heart disease

    In some studies, hawthorn extract used as add-on therapy was found to be beneficial in heart failure patients. More definitive data are needed.
  • To lower high blood pressure

    Data are conflicting. More research is needed.
What are the side effects?
  • Generally well tolerated
  • Most common: Dizziness
  • Infrequent or mild: Nausea, cardiac and gastrointestinal complaints
  • Overdose: Low blood pressure, irregular heart beat
What else do I need to know?

Do Not Take if:

  • You are pregnant.
  • You are taking antiplatelets or anticoagulants: A lab study suggests hawthorn may increase the side effects of these drugs. Although clinical relevance has yet to be determined, patients taking heart failure medications should only use hawthorn under direction and monitoring by the treating physician.
  • You are taking digoxin: Lab studies suggest hawthorn may interfere with some heart medications like digoxin. Therefore, any use of this supplement should be discussed with, and monitored by, your treating physician.

Special Point:

Hawthorn should not be used in place of proven conventional therapies for heart failure, and its use should be monitored by the treating physician.

For Healthcare Professionals

Scientific Name
Crataegus monogyna, Crataegus oxyacantha
Clinical Summary

Derived from the flower, leaves, and fruits of the plant, hawthorn is also popularly referred to as Shan Zha in Asia. It is used in traditional Chinese medicine to improve digestion, stimulate appetite, treat cardiovascular conditions and hyperlipidemia, and invigorate blood (20) (21). Hawthorn extract also has a long history in European medicine as a cardiotonic (22).

In vivo and in vitro studies suggest a broad range of pharmacological properties including anti-inflammatory, gastroprotective, antimicrobial, and cardioprotective effects (15) (20) (23) (24). Clinical studies have shown benefits in patients with congestive heart failure (10) (12) (14), and larger long-term studies of adjunctive hawthorn also suggest benefits (25) (26). In addition, a systematic review concluded that adjunctive hawthorn improved physiological outcomes and symptom control in CHF patients (27). However two smaller trials did not find benefit (28), one of which suggested an increased early risk of disease progression (29). Studies that evaluate the hypotensive effects of hawthorn are mixed (13) (18).

Although data suggest a lack of notable interactions, definitive safety data are needed (22). Hawthorn also should not be used in place of conventional heart failure therapies and its use should be monitored by the treating physician (22).

Purported Uses and Benefits
  • Cardiovascular disease
  • Digestion
  • Hypertension
Mechanism of Action

Pharmacologic activities of hawthorn flower, leaf, and berry extracts are attributed to constituents such as flavonoids and oligomeric procyanidins (17) (22). Laboratory experiments suggest cardiac action of the flavonoids occurs via inhibition of the 3’,5’-cyclic adenosine monophosphate phosphodiesterase, and demonstrate positive inotropic effects by hawthorn that increase heart rate (4). Inotropic and vasodilatory effects have also been related to increased myocardial perfusion and reduced afterload (30). Antioxidant properties and inhibitory effects against LDL oxidation are attributed to phenolic compounds (31).

  • Patients taking digoxin should avoid hawthorn (16).
  • Traditional medicine cautions include the avoidance of hawthorn if you are pregnant.
Adverse Reactions

Generally well tolerated (26) (25) (28) (32)
Most common: Vertigo, dizziness (22)
Infrequent, mild, and transient: Nausea; cardiac and gastrointestinal complaints (14)
Toxicity: Hypotension, arrhythmia (7)

Herb-Drug Interactions
  • Antiplatelets, anticoagulants: An in vitro study suggests hawthorn flowers may inhibit thromboxane A2 biosynthesis, which may increase the side effects of these drugs. Although clinical relevance has yet to be determined, patients taking heart failure medications should not use hawthorn without being closely monitored by the treating physician (30) (33).
  • Digoxin: In vitro data suggest hawthorn contains alkaloids that are structurally similar to digoxin and may interfere with its action (16). However, hawthorn was safely coadministered at a specified dose in a small randomized, crossover trial of healthy volunteers (34). As clinical relevance has yet to be determined, any use of this supplement should be under the guidance of the treating physician.
  • CYP3A4 substrates: In vitro studies suggest hawthorn may affect the metabolism of these drugs at it induces CYP3A4 by activating pregnane X receptor (19). Clinical relevance has yet to be determined.
Dosage (OneMSK Only)
  1. Newall C, et al. Herbal Medicines: A Guide for Health Care Professionals. London: Pharmaceutical Press; 1996.
  2. Tyler V. Herbs of Choice, the Therapeutical Use of Phytomedicinals. Binghamton: Pharmaceutical Press; 1994.
  3. Gildor A. Crataegus oxyacantha and heart failure. Circulation 1998;98:2098.
  4. Schussler M, Holzl J, Fricke U. Myocardial effects of flavonoids from Crataegus species. Arzneimittelforschung 1995;45:843-5.
  5. Upton R, et al. Hawthorn Leaf with flower: quality control, analytical and therapeutical monograph. Belmont (CA): American Herbal Pharmacopoeia; 1999:1-29.
  6. Blumenthal M, et al. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council; 1998.
  7. Iwamoto M, Sato T, Ishizaki T. Klinische Wirkung von Crataegutt bei Herzerkrankungen ischaemischer und/oder hypertensiver Genese. Planta Med 1981;42:1-16.
  8. Brinker, F. Herb Contraindications and Drug Interactions, 2nd ed. Sandy (OR): Eclectic Medical Publications; 1998.
  9. Walker, AF, et al. Promising hypotensive effect of hawthorn extract: a randomized double-blind pilot study of mild, essential hypertension. Phytotherapy Res 2002;16:48-54.
  10. Degenring FH, Suter A, Weber M, Saller R. A randomised double blind placebo controlled clinical trial of a standardised extract of fresh Crataegus berries (Crataegisan) in the treatment of patients with congestive heart failure NYHA II. Phytomedicine. 2003;10(5):363-9.
  11. Werbach MR, et al. Botanical Influences on Illness: A Sourcebook of Clinical Research. Third Line Press, 1994.
  12. Schmidt U, et al. Efficacy of the hawthorn preparation in 78 patients with chronic congestive heart failure defined as NYHA functional class II. Phytomedicine 1994;1:17-24.
  13. Walker AF, Marakis G, Simpson E, et al. Hypotensive effects of hawthorn for patients with diabetes taking prescription drugs: a randomised controlled trial. Br J Gen Pract 2006;56(527):437-43.
  14. Pittler M, Guo R, Ernst E. Hawthorn extract for treating chronic heart failure. Cochrane Database Syst Rev 2008;(1):CD005312.
  15. Tadiæ VM, Dobriæ S, Markoviæ GM, et la. Anti-inflammatory, gastroprotective, free-radical-scavenging, and antimicrobial activities of hawthorn berries ethanol extract. J Agric Food Chem. 2008 Sep 10;56(17):7700-9.
  16. Dasgupta A, Kidd L, Poindexter BJ, Bick RJ. Interference of hawthorn on serum digoxin measurements by immunoassays and pharmacodynamic interaction with digoxin. Arch Pathol Lab Med. 2010 Aug;134(8):1188-92.
  17. Mohamed ME, Frye RF. Effects of herbal supplements on drug glucuronidation. Review of clinical, animal, and in vitro studies. Planta Med. 2011 Mar;77(4):311-21.
  18. Asher GN, Viera AJ, Weaver MA, Dominik R, Caughey M, Hinderliter AL. Effect of hawthorn standardized extract on flow mediated dilation in prehypertensive and mildly hypertensive adults: a randomized, controlled cross-over trial. BMC Complement Altern Med. 2012 Mar 29;12:26.
  19. Xu Y, Zhang Y, Zhou F, et al. Human pregnane X receptor-mediated transcriptional regulation of CYP3A4 by extracts of 7 traditional Chinese medicines. Zhongguo Zhong Yao Za Zhi. 2011 Jun;36(11):1524-7.
  20. Wang J, Xiong X, Feng B. Effect of Crataegus usage in cardiovascular disease prevention: an evidence-based approach. Evid Based Complement Alternat Med. 2013;2013:149363.
  21. Chu SM, Shih WT, Yang YH, et al. Use of traditional Chinese medicine in patients with hyperlipidemia: A population-based study in Taiwan. J Ethnopharmacol. Jun 20 2015;168:129-135.
  22. Dahmer S, Scott E. Health effects of hawthorn. Am Fam Physician. Feb 15 2010;81(4):465-468.
  23. Xia N, Weisenburger S, Koch E, et al. Restoration of perivascular adipose tissue function in diet-induced obese mice without changing bodyweight. Br J Pharmacol. Oct 2017;174(20):3443-3453.
  24. Ranjbar K, Zarrinkalam E, Salehi I, et al. Cardioprotective effect of resistance training and Crataegus oxyacantha extract on ischemia reperfusion-induced oxidative stress in diabetic rats. Biomed Pharmacother. Apr 2018;100:455-460.
  25. Holubarsch CJ, Colucci WS, Meinertz T, et al. The efficacy and safety of Crataegus extract WS 1442 in patients with heart failure: the SPICE trial. Eur J Heart Fail. Dec 2008;10(12):1255-1263.
  26. Tauchert M. Efficacy and safety of Crataegus extract WS 1442 in comparison with placebo in patients with chronic stable New York Heart Association class-III heart failure. Am Heart J. May 2002;143(5):910-915.
  27. Pittler MH, Guo R, Ernst E. Hawthorn extract for treating chronic heart failure. Cochrane Database Syst Rev. Jan 23 2008(1):Cd005312.
  28. Zick SM, Vautaw BM, Gillespie B, et al. Hawthorn Extract Randomized Blinded Chronic Heart Failure (HERB CHF) trial. Eur J Heart Fail. Oct 2009;11(10):990-999.
  29. Zick SM, Gillespie B, Aaronson KD. The effect of Crataegus oxycantha Special Extract WS 1442 on clinical progression in patients with mild to moderate symptoms of heart failure. Eur J Heart Fail. Jun 2008;10(6):587-593.
  30. Tachjian A, Maria V, Jahangir A. Use of herbal products and potential interactions in patients with cardiovascular diseases. J Am Coll Cardiol. Feb 9 2010;55(6):515-525.
  31. Lin HH, Charles AL, Hsieh CW, et al. Antioxidant effects of 14 Chinese traditional medicinal herbs against human low-density lipoprotein oxidation. J Tradit Complement Med. Jan 2015;5(1):51-55.
  32. Holubarsch CJF, Colucci WS, Eha J. Benefit-Risk Assessment of Crataegus Extract WS 1442: An Evidence-Based Review. Am J Cardiovasc Drugs. Feb 2018;18(1):25-36.
  33. Vibes J, Lasserre B, Gleye J, et al. Inhibition of thromboxane A2 biosynthesis in vitro by the main components of Crataegus oxyacantha (Hawthorn) flower heads. Prostaglandins Leukot Essent Fatty Acids. Apr 1994;50(4):173-175.
  34. Tankanow R, Tamer HR, Streetman DS, et al. Interaction study between digoxin and a preparation of hawthorn (Crataegus oxyacantha). J Clin Pharmacol. Jun 2003;43(6):637-642.
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