Drug & supplement interaction

Vitamin A + Doxycyline

Doxycyline brand name: Doxychel.

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

Doxycyline falls into 2 drug categories that Vitamin A can interact with; the most serious is rated moderate. Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.

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

Vitamin A and Doxycyline

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

Why Are There 2 Interactions?

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

Moderate

HEPATOTOXIC DRUGS

1 of 2

Why this applies to Doxycyline

Doxycyline falls under HEPATOTOXIC DRUGS — the group Vitamin A interacts with.

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.
Severity Moderate Likelihood Possible Evidence C

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 gist: both doxycycline and vitamin A can, on rare occasions, put a little extra stress on your liver. Doxycycline isn't a prodrug, so this isn't about one activating the other. Instead, the worry is simply that stacking two things that can each be hard on the liver might add up. Honestly, this is a theoretical concern based mostly on expert opinion, not strong studies.

The real issue is dose. Normal vitamin A from food or a basic multivitamin is very unlikely to matter. High-dose supplements above the safe upper limit are where liver trouble (like raised liver enzymes) becomes more of a concern. If you're taking big doses, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  2. Fritz, H., Kennedy, D., Fergusson, D., Fernandes, R., Doucette, S., Cooley, K., Seely, A., Sagar, S., Wong, R., and Seely, D. Vitamin A and retinoid derivatives for lung cancer: a systematic review and meta analysis. PLoS.One. 2011;6(6):e21107. PubMed
Moderate

TETRACYCLINE ANTIBIOTICS

2 of 2

Doxycyline also falls under TETRACYCLINE ANTIBIOTICS.

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.
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 if you're taking doxycycline along with a vitamin A supplement. Both of these can, on their own, occasionally raise the pressure of fluid around the brain, a condition called pseudotumor cerebri (also known as benign intracranial hypertension). The concern is that pairing them, especially with high-dose vitamin A, might add up and make that more likely. Warning signs would be persistent headaches, blurry or double vision, or nausea.

I want to be honest that this is mostly theoretical and comes from a handful of case reports, so it's not common. A regular multivitamin or food sources of vitamin A are very unlikely to be a problem. But if you're considering a concentrated, high-dose vitamin A supplement while on doxycycline, please check with your pharmacist or doctor first, and don't ignore a new, nagging headache.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hathcock JN, Hattan DG, Jenkins MY, et al. Evaluation of vitamin A toxicity. Am J Clin Nutr 1990;52:183-202.. PubMed
  2. Walters BN, Gubbay SS. Tetracycline and benign intracranial hypertension: report of five cases. Br Med J 1981;282:19-20.. PubMed
  3. Pearson MG, Littlewood SM, Bowden AN. Tetracycline and benign intracranial hypertension (letter). Br Med J 1981;282:568-9.. 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

Vitamin A Also Interacts With Other Medications

Vitamin A has 9 major, 377 moderate known drug interactions in our database — the Doxycyline one above is among them. If you take anything else, check it against the full list below.

Major 9 Moderate 377 No known interaction 2,444 (incl. Doxycyline)
Taking anything else?

Check Another of Your Medications Against Vitamin A

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

From our Q&A

Questions About Vitamin A or Doxycyline

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

This page covers Vitamin A only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxycyline page lists 149 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Asarabacca (major), Beer (major), Oleander (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 132 moderate · 11 minor.

From our pharmacist’s overview on the Doxycyline page

“I read the supplement list for doxycycline (Doxychel) as one to approach with real care, starting with its major-rated entries. Heavy alcohol, including beer and wine, adds to the liver strain this antibiotic can cause, botanicals such as Siberian cocklebur can compound stress on the kidneys, and St.”

Reviewed by 2 · Jul 18, 2026

Open the Doxycyline interaction page

One more smart check

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

We hold 19,215 real supplement products containing Vitamin A, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Vitamin A. Your product may carry other ingredients that interact with Doxycyline too, on top of Vitamin A — 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 Vitamin A and Doxycyline 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 Vitamin A
Top 1%

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

29 days ago today
Medication Doxycyline
Top 25%

#605 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 Vitamin A

What is Vitamin A?

  • Eye and vision health
  • Skin health and acne
  • Immune support
  • Correcting vitamin A deficiency
  • Childhood growth and development

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplements are mainly useful for correcting a true deficiency. Because vitamin A is fat-soluble and can build up to harmful levels, more is not better, and high doses are especially risky in pregnancy.

Read the full Vitamin A monograph & all interactions
Medication

About Doxycycline

What Is Doxycycline Used For?

Brand name: Doxychel

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 & Vitamin A

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

9Major
377Moderate
0Minor
2,443No known interaction
9 Major 377 Moderate 2,443 No interaction
Major

9 interactions

Moderate

377 interactions

Showing 60 of 377 moderate interactions — see all 377 on the Vitamin A page.

No interaction 2,443 drugs checked — show the list

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

Showing the 60 most looked-up of 2,443 medications checked with no known interaction — see the full Vitamin A list.

See the full Vitamin A interactions page
See every supplement checked against Doxycyline, 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
Vitamin A monograph › Uses, safety, and every drug interaction in one place Doxycyline supplement interactions › Every supplement checked against Doxycyline, 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 Vitamin A and Doxycyline Together: Common Questions

Can you take Vitamin A with Doxycyline?
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 Vitamin A and Doxycyline?
Doxycyline belongs to more than one drug category, and Vitamin A 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 Vitamin A and Doxycyline 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

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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.