Drug & supplement interaction

Vitamin O + Clonidine

Clonidine brand name: Catapres.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Vitamin O and Clonidine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Vitamin O and Clonidine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Clonidine and Vitamin O in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Vitamin O at all — not against Clonidine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Vitamin O safety at a glance

Vitamin O overall Use caution Products sold as 'Vitamin O' have unproven claims and their ingredients vary, so quality and safety are uncertain.
Pregnancy Avoid There is no safety data, so avoid during pregnancy.
Breastfeeding Avoid There is no safety data, so avoid while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Clonidine and Vitamin O? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Clonidine’s Own FDA Label Lists

This is not an interaction — none of it involves Vitamin O. These are the most notable effects listed in the ADVERSE REACTIONS section of Clonidine’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 4 of them are worth acting on rather than waiting out — marked below.

  • A slow heartbeat Worth acting on
  • Hallucinations Worth acting on
  • Raised blood pressure Worth acting on mentioned in 5.7% of FDA reports for Clonidine
  • An allergic reaction Worth acting on
  • Vivid dreams or nightmares
  • Mood changes or irritability
  • Tremor or shakiness
  • A stuffy or runny nose
  • Dry mouth
  • A fast or pounding heartbeat

Showing the 10 most notable of 21 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Clonidine. Read the label on DailyMed › Where a percentage is shown, it is the share of 57,112 voluntary FDA FAERS reports for Clonidine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Vitamin O’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Vitamin O side to compare — that is a limit of the record, not a statement that Vitamin O has no side effects.

From our Q&A

Questions About Vitamin O or Clonidine

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 O or Clonidine, 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 Clonidine

This page covers Vitamin O only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clonidine page lists 138 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 · 113 moderate · 21 minor.

From our pharmacist’s overview on the Clonidine page

“American hellebore is the ingredient I would want a clonidine (Catapres) patient to know about first. Its alkaloids lower blood pressure even in small doses and slow the heart, both things clonidine already does, so the combination can drop someone dangerously low.”

Reviewed by 2 · Jul 18, 2026

Open the Clonidine interaction page

How much people look this up

Where Vitamin O and Clonidine 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 O
Steady interest

#1,319 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Clonidine
Top half

#868 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions. Vitamin O is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Vitamin O reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Vitamin O and Clonidine records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Vitamin O

What is Vitamin O?

  • Claimed to add 'stabilized oxygen' to the body
  • General energy and wellness
  • Marketed for improved breathing or vitality

"Vitamin O" is not a real vitamin. It is a marketing name used for liquid products typically containing saltwater (a saline solution) sold with claims of providing 'stabilized oxygen' to the body. There is no credible scientific evidence that these products work, and U.S. regulators have taken action against false advertising for them, so they are best avoided.

Not applicable (manufactured liquid product) · Liquid drops

An interaction check asks whether these two react with each other — it does not ask whether Vitamin O is a good idea for someone in your situation. Here is what our Vitamin O record says about it on its own.

Vitamin O: dosing

There is no established or recommended dose for Vitamin O because it is not a recognized nutrient and has no proven benefit. Different brands give different directions, usually a set number of drops in water.Since the product is unproven, the most cautious advice is to avoid it.

From our Vitamin O monograph — the full record covers uses, side effects and every documented interaction.

Read the full Vitamin O monograph & all interactions
Medication

About Clonidine

What Is Clonidine Used For?

Brand name: Catapres

Clonidine is used to treat high blood pressure (hypertension). Several products — including Clonidine Hydrochloride tablets, Javadin oral solution, Nexiclon XR extended-release tablets, and Catapres-TTS skin patches — are approved for this use, either alone or combined with other blood pressure medicines.

Extended-release formulations — including Onyda XR oral suspension and clonidine hydrochloride extended-release tablets (such as Kapvay) — are approved to treat ADHD in children and teenagers ages 6 to 17, either on their own or alongside stimulant medications. Separately, clonidine injection products (Duraclon and others) are used alongside opioid pain medicines to treat severe cancer pain that opioids alone cannot control adequately.

Most-Reported Side Effects for Clonidine

From FAERS, the FDA’s public side-effect reporting system (57,112 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 3,519 reports
Nausea 3,475 reports
Headache 3,432 reports
Hypertension 3,275 reports
Dyspnea 2,748 reports
See full Clonidine drug information
Keep checking

Other Drugs & Vitamin O

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Vitamin O References

The 2 sources that drive our Vitamin O monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Vitamin O is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Dietary Supplements: What You Need to Know — NIH Office of Dietary Supplements Source
  2. Dietary and Herbal Supplements — NIH National Center for Complementary and Integrative Health Source

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Vitamin O and Clonidine Together: Common Questions

Is it safe to take Vitamin O with Clonidine?
We do not list a known interaction between Vitamin O and Clonidine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Clonidine interact with any supplements?
Yes. Clonidine has documented interactions with 138 supplements in our database — Vitamin O is not one of them. The Clonidine interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Clonidine and Vitamin O?

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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.