What happens when you take metoprolol with hawthorn?
Metoprolol is a beta-1 selective blocker that lowers heart rate and blood pressure by blunting adrenaline at cardiac beta-1 receptors. Hawthorn (Crataegus monogyna or Crataegus laevigata) is an herbal extract from the berries, leaves, and flowers of the hawthorn shrub, traditionally used for heart support and mild blood-pressure lowering. Both push the cardiovascular system in the same direction, so layering them produces an additive effect rather than a metabolic conflict.
- Metoprolol slows the heart and relaxes blood pressure. By blocking beta-1 receptors it reduces how fast and hard the heart beats and lowers blood pressure.
- Hawthorn nudges in the same direction. Hawthorn extracts cause mild vasodilation through nitric-oxide pathways, a small effect on the force of contraction, and modest reductions in heart rate and blood pressure.
- The effects stack at the tissue level. When hawthorn is added on top of metoprolol, blood pressure tends to drop a little further and the pulse to slow a little more.
- Symptoms may appear in vulnerable people. The added drop can show up as lightheadedness on standing, fatigue, or, less often, fainting — mostly in those already near the low end of normal.
- Spacing the doses does not help. Because the interaction is pharmacodynamic, not metabolic, hawthorn does not change how metoprolol is absorbed or cleared. Taking them hours apart still produces the same cumulative effect through systemic exposure.
For most healthy adults with a higher baseline blood pressure, the additive drop is mild and well tolerated. The picture changes for people already running close to the low end, or on several other blood-pressure medications, where the same addition can tip them into symptoms.
Why is this important?
Hawthorn has a generally favorable safety profile when used on its own. Reviews of its use in heart conditions describe small symptom improvements and good tolerability, with side effects such as dizziness, nausea, and digestive upset that are usually mild. A meta-analysis of randomized placebo-controlled trials found that hawthorn produces a modest but real reduction in blood pressure in people with hypertension.
The concern with metoprolol is not that hawthorn is intrinsically dangerous. It is that two agents that each lower heart rate and blood pressure are being stacked, and the people most likely to use both are often the most fragile. Older adults, people with autonomic dysfunction or diabetes, and patients on multi-drug blood-pressure regimens face the greatest risk. Drug-related low blood pressure in older adults is a meaningful driver of falls, fractures, and hospitalization.
Because the interaction is pharmacodynamic and not metabolic, dose-spacing offers no protection. Taking hawthorn at midday and metoprolol at breakfast does not prevent the additive blood-pressure effect, since both reach the heart and vessels through the bloodstream regardless of timing.
What should you do?
Before any change: Do not add hawthorn to your regimen while taking metoprolol without first discussing it with your cardiologist or primary care provider. The right answer depends on why metoprolol was prescribed, where your current blood pressure and pulse sit, and whether you take other cardiovascular medications. Bring a list of every supplement you already take to that conversation.
Every day, if you use both: If your prescriber agrees hawthorn is reasonable to try, check your home blood pressure and pulse regularly during the first several weeks. Watch for blood pressure dropping below your usual goal, a resting pulse slower than normal, or new dizziness on standing, unusual fatigue, or fainting. Take both products consistently as agreed, and do not double up if you miss a dose.
After a change or if symptoms appear: Any new dizziness, faintness, or a pulse or blood pressure that runs lower than expected warrants prompt contact with your prescriber. Do not stop metoprolol on your own — abrupt withdrawal of a beta-blocker can trigger rebound fast heart rate, a sharp rise in blood pressure, or, in people with coronary disease, chest pain or worse. If you want to reduce metoprolol because you feel hawthorn covers similar ground, that decision belongs to your cardiologist. Reassess the combination at every clinic visit.
Which specific products are affected?
Metoprolol is sold as Lopressor (immediate-release tartrate) and Toprol XL (extended-release succinate), along with generics. The additive blood-pressure effect of hawthorn is the same with both formulations.
Hawthorn supplements vary widely. Clinical research has used standardized extracts such as WS 1442 (sold in Europe under brand names like Crataegutt) and LI 132, while generic capsules and dried-herb teas differ in their flavonoid content and effect. Combination herbal heart products that mix hawthorn with motherwort, lily of the valley, or arjuna add further uncertainty, because those herbs carry their own cardiovascular activity.
The concern extends beyond metoprolol. Other beta-blockers — propranolol, atenolol, carvedilol, bisoprolol, nebivolol — and the rate-controlling calcium channel blockers diltiazem and verapamil share the same mechanism. The additive lowering of blood pressure and heart rate is class-based rather than specific to metoprolol.
The science behind it
The evidence here is consistent but modest. The Memorial Sloan Kettering Cancer Center integrative-medicine herb monograph on hawthorn describes its inotropic and vasodilatory cardiovascular effects and cautions that patients taking heart medications should not use hawthorn without close monitoring by their physician. A pharmacology and therapeutic-use review of hawthorn (Rigelsky and Sweet, American Journal of Health-System Pharmacy, 2002; PMID 11887407) describes hawthorn's cardiovascular actions and notes its potential to add to the effects of drugs used for hypertension and heart conditions. A meta-analysis of randomized placebo-controlled trials (PMC12298042) found that hawthorn produces a clinically meaningful but modest reduction in blood pressure in hypertension.
Taken together, these sources support a real but generally mild additive interaction: hawthorn lowers blood pressure on its own, and stacking it on a beta-blocker can add to that effect. None of them describe severe or unpredictable reactions, which is why this is rated moderate rather than high concern.
Frequently Asked Questions
Can I take hawthorn if I'm on metoprolol?
Possibly, but only after your prescriber agrees. Many people tolerate the combination, but because both lower blood pressure and heart rate, the decision should account for your baseline readings and other medications.
Will spacing the doses apart make it safe?
No. The interaction is pharmacodynamic, not metabolic, so it does not matter how many hours separate the two. Both act on the heart and blood vessels through the bloodstream regardless of timing.
What symptoms should make me call my doctor?
New dizziness or lightheadedness on standing, unusual fatigue, a pulse that feels slower than normal, or fainting. These suggest the combined blood-pressure or heart-rate lowering has gone too far.
Is hawthorn dangerous on its own?
For most people it is well tolerated, with mild side effects like dizziness, nausea, or digestive upset. The concern in this article is the additive effect when it is combined with a beta-blocker, not hawthorn by itself.
Can I stop metoprolol and just use hawthorn instead?
No. Hawthorn is not a substitute for metoprolol, and stopping a beta-blocker abruptly can cause a rebound fast heart rate, a spike in blood pressure, or chest pain in people with heart disease. Any change to metoprolol must be directed by your cardiologist.
Does this apply to other heart medications too?
Yes. The same additive concern applies to other beta-blockers and to the rate-controlling calcium channel blockers diltiazem and verapamil, because they lower blood pressure and heart rate through related mechanisms.
Key takeaways
- Hawthorn and metoprolol both lower blood pressure and slow heart rate, so combining them can add up to low blood pressure, a slow pulse, dizziness, or falls.
- The interaction is pharmacodynamic, so taking the doses at different times does not prevent it.
- The effect is real but generally mild; risk is highest in older adults, people with low baseline blood pressure, and those on several other blood-pressure medications.
- Do not add hawthorn on your own, and never stop or reduce metoprolol yourself — abrupt beta-blocker withdrawal can be dangerous.
- Review any plan to use hawthorn with your doctor or pharmacist, and reassess at every clinic visit.