Drug & supplement interaction

Khella + Doxycycline

Doxycycline brand names: Vibra-Tabs, Vibramycin, Doryx, Monodox, Doxycin, and others.

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

Doxycycline falls into 2 drug categories that Khella can interact with; the most serious is rated moderate. Theoretically, concomitant use might result in increased photosensitivity.

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

Khella and Doxycycline

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

Why Are There 2 Interactions?

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

Moderate

PHOTOSENSITIZING DRUGS

1 of 2

Why this applies to Doxycycline

Doxycycline falls under PHOTOSENSITIZING DRUGS — the group Khella interacts with.

Theoretically, concomitant use might result in increased photosensitivity. Khella constituents can cause photosensitivity. Some drugs that cause photosensitivity include amitriptyline (Elavil), quinolones (Ciprofloxacin, others), sulfa drugs (Septra, Bactrim, others), and tetracycline.
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 thing to know about pairing khella with doxycycline: both can make your skin more sensitive to sunlight. Doxycycline is already well known for this on its own. People taking it can sunburn faster than usual, even on a cloudy day or after a short time outside. Khella contains compounds (like khellin) that can do the same thing, so using them together could stack that effect and raise your odds of a painful burn or rash.

To be fair, this is mostly a theoretical concern based on anecdotal reports, not strong studies, so don't panic. Still, it's an easy one to plan around: wear sunscreen, cover up, and limit direct sun. Run it by your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ossenkoppele PM, van der Sluis WG, van Vloten WA. [Phototoxic dermatitis following the use of Ammi majus fruit for vitiligo]. Ned Tijdschr Geneeskd 1991;135:478-80.
  2. Dr. Duke's Phytochemical and Ethnobotanical Databases. Available at: http://www.ars-grin.gov/duke/.
Moderate

HEPATOTOXIC DRUGS

2 of 2

Doxycycline also falls under HEPATOTOXIC DRUGS.

Theoretically, khella might have additive adverse effects on the liver when used with hepatotoxic drugs. Khella can increase liver transaminases. Some drugs that can adversely affect the liver include acetaminophen (Tylenol), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), and many others.
Severity Moderate Likelihood Possible Evidence B

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 concern with pairing khella and doxycycline. Both can occasionally stress the liver. Doxycycline, like other antibiotics in its class, can sometimes raise liver enzymes, and khella has been shown to bump up those same enzymes too. Put them together and the worry is that the two effects could add up, putting a little more strain on your liver than either would alone.

I'll be honest, this is mostly a theoretical caution rather than something we see often, and for most people a normal course of doxycycline is short. Still, watch for warning signs like belly pain, unusual tiredness, dark urine, or yellowing of the skin or eyes. Before combining these, check in with your pharmacist or doctor so they can decide if any liver monitoring makes sense.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Harvengt C, Desager JP. HDL-cholesterol increase in normolipaemic subjects on khellin: a pilot study. Int J Clin Pharmacol Res 1983;3:363-6.

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

Khella Also Interacts With Other Medications

Khella has 617 moderate known drug interactions in our database — the Doxycycline one above is among them. If you take anything else, check it against the full list below.

Moderate 617 No known interaction 2,213 (incl. Doxycycline)
Taking anything else?

Check Another of Your Medications Against Khella

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

From our Q&A

Questions About Khella or Doxycycline

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

This page covers Khella only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxycycline page lists 166 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Oleander (major) and Siberian Cocklebur (major).

By severity: 7 major · 139 moderate · 20 minor.

From our pharmacist’s overview on the Doxycycline page

“St. John's wort is the supplement I would flag first for anyone on doxycycline (Vibramycin, Doryx), because it can speed the antibiotic out of the body and leave an infection undertreated.”

Reviewed by 2 · Jul 18, 2026

Open the Doxycycline interaction page

One more smart check

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

We hold 43 real supplement products containing Khella, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Khella. Your product may carry other ingredients that interact with Doxycycline too, on top of Khella — 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 Khella and Doxycycline 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 Khella
Steady interest

#1,230 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Doxycycline
Top 5%

#39 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 Khella

What is Khella?

Khella
  • Asthma and bronchitis
  • Angina and heart-related chest pain
  • Kidney stones
  • Vitiligo and psoriasis
  • Mild high blood pressure

Khella is a Mediterranean herb whose seeds contain compounds like khellin that may relax smooth muscle in the airways and blood vessels. While it has a long history of traditional use for breathing and heart problems, modern evidence in supplement form is limited, and it can cause side effects and sun sensitivity, so talk with your pharmacist or doctor before using it.

Read the full Khella monograph & all interactions
Medication

About Doxycycline

What Is Doxycycline Used For?

Brand names: Vibra-Tabs, Vibramycin, Doryx, Monodox, Doxycin, Doxy, Doxylin, Doxy-D, Periostat, Doxycycline Injection, Oracea, Xyrosa

Doxycycline belongs to the tetracycline family of antibiotics. It's prescribed for many types of bacterial infections, including respiratory tract infections, sexually transmitted infections (STIs), tick-borne illnesses like Rocky Mountain spotted fever, and eye infections. It's also used to help prevent malaria and, in some cases, as a helper treatment for severe acne.

In situations where penicillin-type antibiotics can't be used — due to allergy, for example — doxycycline can step in as an alternative. It should only be used for infections that are proven or strongly suspected to be caused by bacteria.

See full Doxycycline drug information
Keep checking

Other Drugs & Khella

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

0Major
617Moderate
0Minor
2,212No known interaction
617 Moderate 2,212 No interaction
Moderate

617 interactions

Showing 60 of 617 moderate interactions — see all 617 on the Khella page.

No interaction 2,212 drugs checked — show the list

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

Showing the 60 most looked-up of 2,212 medications checked with no known interaction — see the full Khella list.

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

Can you take Khella with Doxycycline?
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 Khella and Doxycycline?
Doxycycline belongs to more than one drug category, and Khella 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 Khella and Doxycycline 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 Doxycycline and Khella?

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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.