Drug & supplement interaction

Coleus + Valsartan

Valsartan brand names: Diovan, Prexxartan.

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

Valsartan falls into 2 drug categories that Coleus can interact with; the most serious is rated moderate. Theoretically, combining coleus with antihypertensive drugs might cause additive blood pressure lowering effects and increase the risk of hypotension.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Coleus and Valsartan

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Coleus interacts with whole categories of medication. Valsartan falls into 2 of those categories, so it can interact with Coleus in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Valsartan

Valsartan falls under ANTIHYPERTENSIVE DRUGS — the group Coleus interacts with.

Theoretically, combining coleus with antihypertensive drugs might cause additive blood pressure lowering effects and increase the risk of hypotension.
Animal research shows that forskolin, a constituent of coleus, may lower blood pressure.
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. Valsartan already works to bring your blood pressure down by relaxing your blood vessels. Coleus contains a compound called forskolin that, at least in lab and animal studies, may also nudge blood pressure lower. Stack the two together and you could get a bit more lowering than you bargained for.

If your pressure drops too far, you might feel dizzy, lightheaded, tired, or even faint, especially when you stand up quickly. I want to be honest though: this concern is theoretical, based mostly on animal research, not strong human proof. Still, since both can push the same direction, it's worth a quick chat with your pharmacist or doctor before adding Coleus. Please don't change your valsartan on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Baumann G, Felix S, Sattelberger U, Klein G. Cardiovascular effects of forskolin (HL-362) in patients with idiopathic congestiv cardiomyopathy. A comparative study with dobutamine and sodium nitroprusside. J Cardiovasc Pharmacol 1990;16:93-100.
  2. Kramer W, Thormann J, Kindler M, Schlepper M. Effects of forskolin on left ventricular function in dilated cardiomyopathy. Arzneimittelforschung 1987;37:364-7.
  3. Schlepper, M., Thormann, J., and Mitrovic, V. Cardiovascular effects of forskolin and phosphodiesterase-III inhibitors. Basic Res Cardiol 1989;84 Suppl 1:197-212. PubMed
  4. Lindner, E., Dohadwalla, A. N., and Bhattacharya, B. K. Positive inotropic and blood pressure lowering activity of a diterpene derivative isolated from Coleus forskohli: Forskolin. Arzneimittelforschung 1978;28(2):284-289.
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

2 of 2

Valsartan also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, taking coleus may affect drugs metabolized by CYP2C9 and increase the risk of adverse effects or reduce the effectiveness.
Research on the effect of coleus on CYP2C9 is conflicting. Some animal research shows that coleus extract can induce CYP2C9, while in vitro research shows that coleus can inhibit CYP2C9. Until more is known, advise patients that taking coleus might increase or decrease levels of drugs metabolized by CYP2C9.
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 short version on mixing Coleus with your valsartan (Diovan). The concern is that Coleus might tinker with a liver enzyme called CYP2C9, which plays a small part in clearing valsartan from your body. The honest truth is that the science is pretty shaky here. It comes only from lab dishes and animal studies, and the results actually point in opposite directions: some say Coleus speeds that enzyme up, others say it slows it down.

So we genuinely can't say which way it would push your valsartan. In theory, if levels rose you might notice more dizziness or lower blood pressure, and if levels dropped your blood pressure control could slip. On top of that, Coleus itself can nudge blood pressure down. Since this is unproven, please don't change anything on your own. Just run it by me or your doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yokotani K, Chiba T, Sato Y, et al. Hepatic cytochrome P450 mediates interaction between warfarin and Coleus forskohlii extract in vivo and in vitro. J Pharm Pharmacol. 2012;64(12):1793-801.

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

Coleus Also Interacts With Other Medications

Coleus has 29 major, 885 moderate known drug interactions in our database — the Valsartan one above is among them. If you take anything else, check it against the full list below.

Major 29 Moderate 885 No known interaction 1,916 (incl. Valsartan)
Taking anything else?

Check Another of Your Medications Against Coleus

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

From our Q&A

Questions About Coleus or Valsartan

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

This page covers Coleus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valsartan page lists 182 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 · 145 moderate · 33 minor.

From our pharmacist’s overview on the Valsartan page

“Of the 182 supplements and herbs on file for valsartan (Diovan), a medication for high blood pressure and heart failure, most either deepen its blood-pressure-lowering effect or work against it, and the four rated major deserve genuine respect before the rest of the page. Activated charcoal can cut the absorption of oral doses, and the…”

Reviewed by 2 · Jul 18, 2026

Open the Valsartan interaction page

One more smart check

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

We hold 803 real supplement products containing Coleus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coleus. Your product may carry other ingredients that interact with Valsartan too, on top of Coleus — 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 Coleus and Valsartan 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 Coleus
Top 25%

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

29 days ago today
Medication Valsartan
Top 5%

#107 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 Coleus

What is Coleus?

Coleus
  • Weight management
  • Asthma and breathing
  • High blood pressure
  • Heart conditions
  • Glaucoma (eye pressure)
  • Exercise and body composition

Coleus is a plant from the mint family whose root contains a compound called forskolin, often marketed for weight loss, asthma, and heart health. While early lab and small human studies are interesting, solid proof that Coleus supplements help any of these conditions is limited. Talk to your pharmacist or doctor before using it, especially if you have heart problems or low blood pressure.

Read the full Coleus monograph & all interactions
Medication

About Valsartan

What Is Valsartan Used For?

Brand names: Diovan, Prexxartan

Valsartan treats high blood pressure (hypertension) in adults and children, heart failure in adults, and reduces the risk of cardiovascular death in adults who have had a heart attack and have a weakened heart muscle. Lowering blood pressure reduces the risk of stroke and heart attack.

Diovan (valsartan) tablets are approved to treat high blood pressure in children as young as 1 year old. Valsartan tablets (other brands) are approved for children 6 years and older. Valsartan oral solution is specifically indicated for patients with heart failure or post-heart attack left ventricular dysfunction who are unable to swallow tablets.

See full Valsartan drug information
Keep checking

Other Drugs & Coleus

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

29Major
885Moderate
0Minor
1,915No known interaction
29 Major 885 Moderate 1,915 No interaction
Major

29 interactions

Moderate

885 interactions

Showing 60 of 885 moderate interactions — see all 885 on the Coleus page.

No interaction 1,915 drugs checked — show the list

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

Showing the 60 most looked-up of 1,915 medications checked with no known interaction — see the full Coleus list.

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

Can you take Coleus with Valsartan?
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.
Why are there 2 interactions listed for Coleus and Valsartan?
Valsartan belongs to more than one drug category, and Coleus interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Coleus and Valsartan 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 Valsartan and Coleus?

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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.