Drug & supplement interaction

Cocoa + Hydralazine

Hydralazine brand names: Apresoline, Hylazin, Hydralazine, Dralzine, Apresoline Injection.

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

Cocoa has a moderate interaction with Hydralazine. Theoretically, taking cocoa with antihypertensive drugs might increase the risk of hypotension.

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

Cocoa and Hydralazine

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Hydralazine

Hydralazine falls under ANTIHYPERTENSIVE DRUGS — the group Cocoa interacts with.

Theoretically, taking cocoa with antihypertensive drugs might increase the risk of hypotension.
Clinical research shows that cocoa can modestly decrease blood pressure in hypertensive and normotensive patients.
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 simple version: hydralazine works by relaxing your blood vessels so blood flows more easily, which brings your blood pressure down. Cocoa flavanols seem to do a little of the same thing by helping vessels widen. Stack them together and, in theory, your pressure could dip a bit lower than expected.

If that happens, you might feel lightheaded, dizzy, flushed, or get a headache or a faster heartbeat, especially when you stand up quickly. I want to be honest though: this concern is mostly theoretical, based on how the two work, and a square of chocolate or a normal cup of cocoa is unlikely to matter. Concentrated cocoa supplements are more of a question. If you're considering those, check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Taubert D, Berkels R, Roesen R, Klaus W. Chocolate and blood pressure in elderly individuals with isolated systolic hypertension. JAMA 2003;290:1029-30.. PubMed
  2. Grassi D, Necozione S, Lippi C, et al. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. Hypertension 2005;46:398-405. PubMed
  3. Taubert D, Roesen R, Schomig E. Effect of cocoa and tea intake on blood pressure: a meta-analysis. Arch Intern Med 2007;167:626-34. PubMed
  4. Taubert D, Roesen R, Lehmann C, et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA 2007;298:49-60. PubMed
  5. Hooper L, Kay C, Abdelhamid A, et al. Effects of chocolate, cocoa, and flavan-3-ols on cardiovascular health: a systematic review and meta-analysis of randomized trials. Am J Clin Nutr 2012;95:740-51. PubMed
  6. Hooper, L., Kroon, P. A., Rimm, E. B., Cohn, J. S., Harvey, I., Le Cornu, K. A., Ryder, J. J., Hall, W. L., and Cassidy, A. Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2008;88 PubMed
  7. Desch, S., Schmidt, J., Kobler, D., Sonnabend, M., Eitel, I., Sareban, M., Rahimi, K., Schuler, G., and Thiele, H. Effect of cocoa products on blood pressure: systematic review and meta-analysis. Am J Hypertens. 2010;23(1):97-103. PubMed
  8. Ried, K., Sullivan, T., Fakler, P., Frank, O. R., and Stocks, N. P. Does chocolate reduce blood pressure? A meta-analysis. BMC.Med 2010;8:39. PubMed
  9. Shrime, M. G., Bauer, S. R., McDonald, A. C., Chowdhury, N. H., Coltart, C. E., and Ding, E. L. Flavonoid-rich cocoa consumption affects multiple cardiovascular risk factors in a meta-analysis of short-term studies. J Nutr 2011;141(11):1982-1988. PubMed
  10. Sudarma, V., Sukmaniah, S., and Siregar, P. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects. Acta Med.Indones. 2011;43(4):224-228.
  11. Ried, K., Sullivan, T. R., Fakler, P., Frank, O. R., and Stocks, N. P. Effect of cocoa on blood pressure. Cochrane.Database.Syst.Rev. 2012;8:CD008893. PubMed
  12. Jafarnejad S, Salek M, Clark CCT. Cocoa consumption and blood pressure in middle-aged and elderly subjects: a meta-analysis. Curr Hypertens Rep. 2020;22(1):1. PubMed
  13. Balayssac-Siransy E, Ouattara S, Boka KJM, et al. Dose-effect relation between regular consumption of 100% cocoa powder and blood pressure in young, healthy black Africans. Physiol Rep 2021;9(20):e15070. PubMed

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

Cocoa Also Interacts With Other Medications

Cocoa has 634 moderate, 26 minor known drug interactions in our database — the Hydralazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 634 Minor 26 No known interaction 2,170 (incl. Hydralazine)
Taking anything else?

Check Another of Your Medications Against Cocoa

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

From our Q&A

Questions About Cocoa or Hydralazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cocoa or Hydralazine, 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 Hydralazine

This page covers Cocoa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydralazine page lists 136 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 111 moderate · 21 minor.

From our pharmacist’s overview on the Hydralazine page

“Hydralazine is the drug doctors reach for when blood pressure needs forcing down, so I read this list of 136 supplement interactions with genuine concern rather than routine caution. Start with the four rated major: two are toxic plants with direct effects on the heart and blood vessels, tyramine can push pressure back up and undo the…”

Reviewed by 2 · Jul 18, 2026

Open the Hydralazine interaction page

One more smart check

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

We hold 844 real supplement products containing Cocoa, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cocoa. Your product may carry other ingredients that interact with Hydralazine too, on top of Cocoa — 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 Cocoa and Hydralazine 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 Cocoa
Top 25%

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

29 days ago today
Medication Hydralazine
Top 25%

#568 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 Cocoa

What is Cocoa?

Cocoa
  • Heart and blood vessel health
  • High blood pressure
  • High cholesterol
  • Mental focus and mood
  • Skin moisturizing (cocoa butter)

Cocoa is rich in plant compounds called flavanols that may modestly support blood vessel function and blood pressure, but most chocolate products are high in sugar, fat, and calories, which can offset any benefit. Enjoy cocoa as part of a balanced diet, and talk to your pharmacist before using concentrated cocoa supplements, especially if you have heart or blood pressure conditions.

Read the full Cocoa monograph & all interactions
Medication

About Hydralazine

What Is Hydralazine Used For?

Brand names: Apresoline, Hylazin, Hydralazine, Dralzine, Apresoline Injection

Hydralazine tablets are used to treat essential hypertension (high blood pressure), either alone or alongside other blood pressure medications.

The hydrALAZINE Hydrochloride injection form is used in hospital settings for severe essential hypertension when oral medication cannot be taken or when blood pressure needs to be lowered urgently.

See full Hydralazine drug information
Keep checking

Other Drugs & Cocoa

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

0Major
634Moderate
26Minor
2,169No known interaction
634 Moderate 26 Minor 2,169 No interaction
Moderate

634 interactions

Showing 60 of 634 moderate interactions — see all 634 on the Cocoa page.

Minor

26 interactions

No interaction 2,169 drugs checked — show the list

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

Showing the 60 most looked-up of 2,169 medications checked with no known interaction — see the full Cocoa list.

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

Can you take Cocoa with Hydralazine?
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 Cocoa and Hydralazine 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 Hydralazine and Cocoa?

Our pharmacists answer your medication & supplement questions — free.

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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.