The short answer
It is not established that hawthorn causes harmful low blood pressure when taken with enalapril. Some hawthorn research shows a small pressure reduction, but the products and medicines studied do not establish this exact combination. Ask your pharmacist or prescriber to review the product before starting it.
What this answer covers
Oral Crataegus monogyna products with oral enalapril. Species, plant part, extraction method and strength need to be identified. Evidence for other hawthorn species, mixed extracts or root products is not automatically applicable.
- Supplement or preparation
- Hawthorn (Crataegus monogyna)
- Medication ingredient
- enalapril
What did the human study show?
A 16-week trial assigned 79 adults with type 2 diabetes to hawthorn extract or placebo. The average lower blood-pressure number fell slightly more with hawthorn. The investigators did not identify an herb-drug interaction, but the trial was too small and too broad to rule out problems with a particular medicine.
Does that study cover this hawthorn product?
The abstract describes hawthorn as Crataegus laevigata, while this page concerns Crataegus monogyna. It also included people taking several types of medicine. Without confirmation of the exact species, plant part and formulation, its results cannot be treated as a direct test of your product. The two botanical names should not be used interchangeably.
Do laboratory studies or side-effect reports settle the question?
An experiment found that a hawthorn fruit extract inhibited a blood-pressure enzyme in a laboratory. It did not test either medicine together with hawthorn in people. A later analysis of hawthorn side-effect reports also could not establish the risk for this exact combination. These sources explain a reason for caution, while leaving the size and likelihood of any interaction uncertain.
When does low blood pressure need attention?
Enalapril itself can cause low blood pressure. The concern is greater with dehydration, some diuretics, heart failure or already low readings. Hawthorn can also cause dizziness, which does not prove an interaction. Report new lightheadedness or unusual weakness, and obtain urgent medical assessment for fainting or severe symptoms.
Would taking them at different times help?
No reliable spacing interval was established by the sources checked. Moving the supplement to another time of day should not be presented as a proven solution. Bring the bottle or a clear ingredient list, dose and recent blood-pressure readings to your pharmacist; do not replace or adjust the prescribed medicine yourself.
Evidence and practical considerations
Side effects & toxicity
It is not established that hawthorn causes harmful low blood pressure when taken with enalapril. Some hawthorn research shows a small pressure reduction, but the products and medicines studied do not establish this exact combination. Ask your pharmacist or prescriber to review the product before starting it.
- Exact scope
- Oral Crataegus monogyna products with oral enalapril. Species, plant part, extraction method and strength need to be identified. Evidence for other hawthorn species, mixed extracts or root products is not automatically applicable. with Enalapril, RxCUI 3827, IN. Oral enalapril maleate tablets are an explicitly identified salt formulation of enalapril in the label. This bridge applies to the labeled oral prodrug; injected enalaprilat, other ACE inhibitors and combination products are not assigned this evidence automatically.
- Medication form and route
- oral
- Timing or duration
- Limited to the exposure durations described in the sources; no untested duration or timing rule is inferred.
What remains uncertain
- The main trial had mixed antihypertensive exposure and an unresolved-to-different botanical identity relative to C. monogyna. Neither exact medication was isolated, and excess symptomatic hypotension was not established. No demonstrated pair-specific timing rule. The in vitro fruit-extract experiment and spontaneous adverse-event reports do not establish an exact clinical interaction.
Factors that may matter: exact preparation and dose; baseline blood pressure; kidney function; diuretics and other medicines; dehydration.
Read the supporting source summaries
Source 1: regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral enalapril maleate for hypertension or heart failure.
Potassium products can substantially increase serum potassium; when indicated for documented low potassium, use cautiously with frequent testing. Dehydration and intensive diuretic treatment increase hypotension risk.
How this applies: The maleate formulation is explicitly identified as a salt of enalapril. Applies to oral enalapril, RxCUI 3827 IN; does not transfer to injected enalaprilat or another ACE inhibitor.
A drug label supports named warnings, not every botanical combination. Trial hyperkalemia rates are for enalapril treatment and do not quantify the incremental risk of potassium supplements. The inspected US label has no antacid-specific paragraph.
Source 2: primary randomized controlled trial
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 79 adults with type 2 diabetes; 71% used blood-pressure medicines of mixed types.
Diastolic pressure changed from 85.6 to 83.0 mmHg with hawthorn versus 84.5 to 85.0 with placebo; between-group P=0.035. Systolic difference was not significant. Authors did not identify an herb-drug interaction.
How this applies: Context only. Different or incompletely resolved hawthorn species and mixed medication exposure prevent transfer as direct evidence for C. monogyna with either exact medication.
Abstract-only access: no verification of a C. monogyna-only exposure or an isolated enalapril/lisinopril subgroup. A small pressure reduction does not prove symptomatic hypotension. No interaction detected is not proof that all products are safe.
Source 3: government botanical safety reference
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of diverse hawthorn products.
Reports uncertainty about safety and possible dizziness and gastrointestinal effects; advises discussing herbal products with a healthcare professional when taking medicines.
How this applies: Supports cautious product review and species boundaries; not direct-pair evidence.
The cited heart-failure concern concerns a C. oxycantha preparation, and adulterated tejocote products concern other plants. Neither establishes a C. monogyna interaction with enalapril or lisinopril.
Source 4: primary pharmacovigilance analysis with scoping review
pmc.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 1527 VigiBase reports from 1970 through October 25, 2023, plus 13 Lareb reports; patients using diverse hawthorn products.
In 277 VigiBase reports a single-herb hawthorn product was the only suspect; 12.6% of those reports were classified serious. Reports included cardiac and gastrointestinal symptoms. No exact lisinopril or enalapril subgroup was established.
How this applies: Context for uncertainty and possible adverse reactions only. Mixed species, preparations and medications do not establish the exact C. monogyna pair.
Spontaneous reports cannot establish event frequency or causality. VigiBase narratives were unavailable and no disproportionality analysis was done. The discussion cites an in vitro ACE assay for stronger effects with ACE inhibitors; this does not establish human co-use harm.
Source 5: primary in vitro experiment
journals.sagepub.com · Source check Sep 10, 2026
Population: Laboratory enzyme assay; no human or animal participants.
The extract inhibited ACE in vitro with IC50 335 micrograms/mL, versus 3.61 micromolar for oleanolic acid and approximately 0.047 micromolar for captopril.
How this applies: Supports a possible biochemical mechanism for this fruit extract only. It cannot prove harmful hypotension with either exact drug, nor be generalized to all hawthorn parts or extracts.
No oral dosing, blood-pressure measurement, enalapril or lisinopril exposure, or medication-supplement co-administration was studied. Enzyme inhibition cannot establish clinical efficacy, safety or dose-spacing advice.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Original sources checked and a new article prepared, distinguishing the exact medicine and supplement preparation from related studies. No independent clinical review is recorded. | |
| Research summary published |
Article revision: 5b978b26ed317e26
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.