Drug & supplement interaction

Guaiac Wood + Promethazine

Promethazine brand name: Phenergan.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Guaiac Wood and Promethazine 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

Guaiac Wood and Promethazine

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 Promethazine and Guaiac Wood 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.

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.

Guaiac Wood safety at a glance

Guaiac Wood overall Use caution Mostly used externally or as a scent; little safety data for internal use.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid No reliable safety data while breastfeeding, so avoid use.

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

Still wondering about combining Promethazine and Guaiac Wood? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Promethazine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Promethazine is filed under 4 classifications — including phenothiazines, anticholinergic drugs, photosensitizing drugs. Guaiac Wood has documented interactions with 1 drug class — the most serious being lithium (moderate) — and none of Promethazine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Guaiac Wood Does Interact With Other Medications

Guaiac Wood has 1 moderate known drug interaction in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 1 No known interaction 2,829 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Guaiac Wood

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

What to actually watch for

What Guaiac Wood Itself Has Been Linked To

This is not an interaction — nothing below involves Promethazine. It is the side-effect record for Guaiac Wood on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Guaiac Wood, this list is the first place to look.

  • Diarrhea Additional detail

    “Orally, high doses of guaiac wood can cause diarrhea, gatroenteritis, or intestinal colic (18).”

    Guaiac Wood · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

Everything above comes from the Natural Medicines adverse-effect record for Guaiac Wood — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Promethazine’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Promethazine column appears here.

From our Q&A

Questions About Guaiac Wood or Promethazine

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

This page covers Guaiac Wood only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 23 minor.

From our pharmacist’s overview on the Promethazine page

“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Promethazine interaction page

How much people look this up

Where Guaiac Wood and Promethazine 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 Guaiac Wood
Steady interest

#1,131 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Promethazine
Top half

#1,059 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.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Guaiac Wood reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Guaiac Wood and Promethazine records this page draws on were last updated July 10, 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 Guaiac Wood

What is Guaiac Wood?

  • Fragrance in perfumes and soaps
  • Aromatherapy and relaxation
  • Traditional anti-inflammatory remedy
  • Skin care products
  • Traditional joint and arthritis support

Guaiac wood is mainly valued for its sweet, smoky-rosy aroma and is used widely as a fragrance ingredient and in aromatherapy. There is very little high-quality human research supporting any health or medical benefit, so it should be thought of as a scent rather than a proven remedy. If you want to use it, talk to your pharmacist or doctor first, and avoid taking it by mouth.

Bulnesia sarmientoi · Zygophyllaceae · Wood and essential oil (also called guaiacwood oil) · Essential oil, aromatherapy blends, soaps and perfumes; sometimes wood chips or resin

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

Guaiac Wood: dosing

There is no established or standardized medical dose for guaiac wood. It is most often used in small amounts as a fragrance in finished products such as soaps, perfumes, or aromatherapy diffuser blends.If you choose to use a guaiac wood product, follow the directions on the label and dilute essential oils properly before applying them to skin.

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

Read the full Guaiac Wood monograph & all interactions
Medication

About Promethazine

What Is Promethazine Used For?

Brand name: Phenergan

Promethazine is used for a wide range of conditions. Tablets, oral solution, and rectal suppositories (brands including Phenergan, Promethegan, and Phenadoz) are approved for seasonal and perennial allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, hives (urticaria), angioedema, dermographism, and allergic reactions to blood or plasma. They are also used for motion sickness (both prevention and active treatment), nausea and vomiting related to anesthesia and surgery, sedation, and as a helper medication alongside pain relievers after surgery.

Promethazine hydrochloride injection (brands including Phenergan and Promethazine HCl injection) is used for many of the same purposes but is reserved for situations where oral treatment is not possible — including allergic emergencies as an adjunct to epinephrine, sedation during labor, and as an aid during certain surgical procedures such as bronchoscopy and eye surgery.

Most-Reported Side Effects for Promethazine

From FAERS, the FDA’s public side-effect reporting system (22,614 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dependence 3,586 reports
Nausea 2,646 reports
Vomiting 1,802 reports
Fatigue 1,496 reports
Diarrhea 1,341 reports
See full Promethazine drug information
Keep checking

Other Drugs & Guaiac Wood

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

0Major
1Moderate
0Minor
2,828No known interaction
1 Moderate 2,828 No interaction
Moderate

1 interaction

No interaction 2,828 drugs checked — show the list

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

Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Guaiac Wood list.

See the full Guaiac Wood interactions page
See every supplement checked against Promethazine, ranked by severity
Evidence & sources

Guaiac Wood References

The 1 references that drive our Guaiac Wood monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Guaiac Wood and Promethazine Together: Common Questions

Is it safe to take Guaiac Wood with Promethazine?
We do not list a known interaction between Guaiac Wood and Promethazine. 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.
How was the Guaiac Wood and Promethazine combination checked?
Interactions in our licensed database are recorded against drug classes. Promethazine is filed under 4 classifications, and Guaiac Wood has documented interactions with 1 drug class — none of Promethazine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Guaiac Wood interact with any other medications?
Yes. Guaiac Wood has 1 documented drug interaction in our database — Promethazine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Promethazine interact with any supplements?
Yes. Promethazine has documented interactions with 83 supplements in our database — Guaiac Wood is not one of them. The Promethazine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Guaiac Wood monograph Uses, safety profile, and every drug interaction in one place Promethazine drug information The full plain-English guide to this medication Promethazine supplement interactions Every supplement checked against Promethazine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Promethazine and Guaiac Wood?

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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.