Drug & supplement interaction

Aspen + Propylthiouracil, PTU

Propylthiouracil, PTU brand name: Propylthiouracil.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Aspen and Propylthiouracil, PTU 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Aspen and Propylthiouracil, PTU

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 Propylthiouracil, PTU and Aspen 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.

Aspen safety at a glance

Aspen overall Use caution It contains aspirin-like salicylates and may cause similar side effects, so use carefully.
Pregnancy Avoid Because of its aspirin-like activity and lack of safety data, it is best avoided during pregnancy.
Breastfeeding Avoid Not enough is known about safety, and salicylates can pass into breast milk, so avoid use.

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

Still wondering about combining Propylthiouracil, PTU and Aspen? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Propylthiouracil, PTU

Interactions in our licensed database are recorded against drug classes, not just single drug names. Propylthiouracil, PTU is filed under 3 classifications — antithyroid drugs, hepatotoxic drugs, oral drugs. Aspen has documented interactions with 3 drug classes — the most serious being aspirin (moderate), choline magnesium trisalicylate (trilisate) (moderate) and salsalate (disalcid) (moderate) — and none of Propylthiouracil, PTU’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

Aspen Does Interact With Other Medications

Aspen has 39 moderate known drug interactions in our database — Propylthiouracil, PTU isn’t one of them. If you take anything else, check it against the full list below.

Moderate 39 No known interaction 2,791 (incl. Propylthiouracil, PTU)
Taking anything else?

Check Another of Your Medications Against Aspen

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

What to actually watch for

No Interaction Found — But Data Suggests Aspen and Propylthiouracil, PTU May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • A skin rash Additional detail

    Aspen

    “There is currently a limited amount of information available about the adverse effects of aspen. Aspen contains salicin, a plant salicylate. Theoretically, aspen taken orally may be associated with the adverse effects seen with other salicylates, such as aspirin. Topically, aspen has been associated with allergic dermatitis.”

    Aspen · Natural Medicines adverse-effect record, reported in dermatitis.

    2 sources cited
    1. 3700. Goodman LS, Gilman A. The Pharmacological Basis of Therapeutics. 5th ed. New York, NY: Macmillan Publ. Co., Inc., 1975.
    2. 101465. Aalto-Korte K, Välimaa J, Henriks-Eckerman ML, Jolanki R. Allergic contact dermatitis from salicyl alcohol and salicylaldehyde in aspen bark (Populus tremula). Contact Dermatitis 2005;52(2):93-5.

    “A case report describes a 58-year-old man who developed allergic contact dermatitis after handling aspen leaves and bark. The rash spread from his hands to his face, trunk, and extremities. He had positive skin patch tests to salicyl alcohol and salicylaldehyde, which are present in aspen as glucosides, such as salicin.”

    Aspen · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 101465. Aalto-Korte K, Välimaa J, Henriks-Eckerman ML, Jolanki R. Allergic contact dermatitis from salicyl alcohol and salicylaldehyde in aspen bark (Populus tremula). Contact Dermatitis 2005;52(2):93-5.

    Propylthiouracil, PTU

    Listed in the ADVERSE REACTIONS section of the FDA label for Propylthiouracil, PTU. Read the label on DailyMed ›

Effects for Propylthiouracil, PTU come from the ADVERSE REACTIONS section of its FDA label; effects for Aspen come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 2,050 voluntary FDA FAERS reports for Propylthiouracil, PTU that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Aspen or Propylthiouracil, PTU

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

This page covers Aspen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Propylthiouracil, PTU page lists 64 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ascophyllum Nodosum (moderate).

By severity: 4 major · 51 moderate · 9 minor.

Open the Propylthiouracil, PTU interaction page

One more smart check

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

We hold 8 real supplement products containing Aspen, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Aspen. Even though Aspen itself has no known interaction with Propylthiouracil, PTU, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Aspen and Propylthiouracil, PTU 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 Aspen
Steady interest

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

29 days ago today
Medication Propylthiouracil, PTU
Steady interest

#2,072 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 Aspen reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Aspen and Propylthiouracil, PTU 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 Aspen

What is Aspen?

Aspen
  • Joint and muscle pain
  • Arthritis-related discomfort
  • Urinary tract symptoms and prostate issues
  • Mild fever and inflammation
  • Nerve pain (sciatica, neuropathic pain)

Aspen bark and leaf contain salicin, a natural compound related to aspirin, which is why it is traditionally used for pain, fever, and inflammation. Solid human studies are lacking, and because it acts like aspirin it carries similar risks. Talk to your pharmacist or doctor before using it, especially if you are sensitive to aspirin.

Populus tremuloides · Salicaceae · Bark and leaves (sometimes leaf buds) · Capsules, tinctures, liquid extracts, teas, and dried bark; often combined with other herbs

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

Aspen: dosing

There is no well-established, standardized dose for aspen. The amount of salicin in products can vary widely, and many products combine aspen with other herbs.The safest approach is to follow the directions on the specific product label and not exceed the recommended amount.

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

Read the full Aspen monograph & all interactions
Medication

About Propylthiouracil

What Is Propylthiouracil Used For?

Brand name: Propylthiouracil

Propylthiouracil tablets treat hyperthyroidism (an overactive thyroid). They are meant for people who cannot tolerate methimazole, another antithyroid medicine.

The tablets are used in two situations: Graves’ disease with hyperthyroidism or toxic multinodular goiter when surgery or radioactive iodine is not a good option, and easing symptoms before thyroid surgery or radioactive iodine therapy.

See full Propylthiouracil drug information
Keep checking

Other Drugs & Aspen

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

0Major
39Moderate
0Minor
2,790No known interaction
39 Moderate 2,790 No interaction
Moderate

39 interactions

No interaction 2,790 drugs checked — show the list

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

Showing the 60 most looked-up of 2,790 medications checked with no known interaction — see the full Aspen list.

See the full Aspen interactions page
See every supplement checked against Propylthiouracil, PTU, ranked by severity
Evidence & sources

Aspen References

The 3 references that drive our Aspen 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. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Goodman LS, Gilman A. The Pharmacological Basis of Therapeutics. 5th ed. New York, NY: Macmillan Publ. Co., Inc., 1975.
  3. Aalto-Korte K, Välimaa J, Henriks-Eckerman ML, Jolanki R. Allergic contact dermatitis from salicyl alcohol and salicylaldehyde in aspen bark (Populus tremula). Contact Dermatitis 2005;52(2):93-5.

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 Aspen and Propylthiouracil, PTU Together: Common Questions

Is it safe to take Aspen with Propylthiouracil, PTU?
We do not list a known interaction between Aspen and Propylthiouracil, PTU. 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.
Do Aspen and Propylthiouracil, PTU have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Aspen and Propylthiouracil, PTU combination checked?
Interactions in our licensed database are recorded against drug classes. Propylthiouracil, PTU is filed under 3 classifications, and Aspen has documented interactions with 3 drug classes — none of Propylthiouracil, PTU'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 Aspen interact with any other medications?
Yes. Aspen has 39 documented drug interactions in our database — Propylthiouracil, PTU 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 Propylthiouracil, PTU interact with any supplements?
Yes. Propylthiouracil, PTU has documented interactions with 64 supplements in our database — Aspen is not one of them. The Propylthiouracil, PTU 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

Aspen monograph Uses, safety profile, and every drug interaction in one place Propylthiouracil drug information The full plain-English guide to this medication Propylthiouracil, PTU supplement interactions Every supplement checked against Propylthiouracil, PTU, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Propylthiouracil, PTU and Aspen?

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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.