Drug & supplement interaction

Thymus Extract + Promethazine

Promethazine brand name: Phenergan.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Thymus Extract 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.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Thymus Extract 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 Thymus Extract 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.

Thymus Extract safety at a glance

Thymus Extract overall Use caution Human safety data are limited, and animal-tissue products carry a small risk of contamination.
Pregnancy Avoid There is not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety during breastfeeding is unknown, so avoid use.

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

Still wondering about combining Promethazine and Thymus Extract? 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. Thymus Extract has documented interactions with 1 drug class — the most serious being immunosuppressants (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

Thymus Extract Does Interact With Other Medications

Thymus Extract has 121 moderate known drug interactions in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Thymus Extract

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

What to actually watch for

What Promethazine’s Own FDA Label Lists

This is not an interaction — none of it involves Thymus Extract. These are the most notable effects listed in the ADVERSE REACTIONS section of Promethazine’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. 10 of them are worth acting on rather than waiting out — marked below.

  • A slow heartbeat Worth acting on
  • Hallucinations Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • Wheezing Worth acting on
  • Confusion Worth acting on
  • Seizures Worth acting on
  • A low platelet count Worth acting on
  • Hives Worth acting on
  • A low white blood cell count Worth acting on
  • Bleeding or bruising Worth acting on

Showing the 10 most notable of 26 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 Promethazine. Read the label on DailyMed › Where a percentage is shown, it is the share of 22,361 voluntary FDA FAERS reports for Promethazine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Thymus Extract’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Thymus Extract side to compare — that is a limit of the record, not a statement that Thymus Extract has no side effects.

From our Q&A

Questions About Thymus Extract 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 Thymus Extract 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 Thymus Extract 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 Thymus Extract 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 Thymus Extract
Steady interest

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

29 days ago today
Medication Promethazine
Steady interest

#2,128 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 Thymus Extract reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Thymus Extract 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 Thymus Extract

What is Thymus Extract?

  • Immune system support
  • Frequent infections
  • Allergies
  • Autoimmune conditions
  • Cancer supportive care

Thymus extract is a glandular product made from the thymus tissue of animals, and it is promoted mainly for immune support. The evidence is mostly limited, preliminary, or from older studies, so it should not replace proven treatments. Because it is an animal-tissue product, talk with your pharmacist or doctor before using it, especially if you have a serious medical condition.

Thymus gland tissue, usually from cattle or sheep · Capsules, tablets, oral liquid, injectable preparations (in some countries)

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

Thymus Extract: dosing

There is no well-established standard dose for thymus extract, and products vary widely in their strength and source. Do not assume that taking more is safer or more effective.

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

Read the full Thymus Extract 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 & Thymus Extract

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

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Thymus Extract page.

No interaction 2,708 drugs checked — show the list

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

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Thymus Extract list.

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

Thymus Extract References

The 2 references that drive our Thymus Extract 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. Lewis CJ. Letter to reiterate certain public health and safety concerns to firms manufacturing or importing dietary supplements that contain specific bovine tissues. FDA. Available at: www.cfsan.fda.gov/~dms/dspltr05.html.
  2. Nationwide alert on hallmark labs injectable adrenal cortex extract. FDA. Available at: www.fda.gov/bbs/topics/NEWS/NEW00539.html

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 Thymus Extract and Promethazine Together: Common Questions

Is it safe to take Thymus Extract with Promethazine?
We do not list a known interaction between Thymus Extract 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 Thymus Extract and Promethazine combination checked?
Interactions in our licensed database are recorded against drug classes. Promethazine is filed under 4 classifications, and Thymus Extract 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 Thymus Extract interact with any other medications?
Yes. Thymus Extract has 121 documented drug interactions 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 — Thymus Extract 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

Thymus Extract 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Promethazine and Thymus Extract?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.