Drug & supplement interaction

Aspen + Pacritinib

Pacritinib brand name: Vonjo.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Aspen and Pacritinib 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

Aspen and Pacritinib

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 Pacritinib 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 Pacritinib and Aspen? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Pacritinib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Pacritinib is filed under 5 classifications — including cytochrome p450 1a2 (cyp1a2) inhibitors, qt interval-prolonging drugs, cytochrome p450 3a4 (cyp3a4) inhibitors. 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 Pacritinib’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 — Pacritinib 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. Pacritinib)

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

What Aspen Itself Has Been Linked To

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

A skin rash Additional detail
“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

3700. Goodman LS, Gilman A. The Pharmacological Basis of Therapeutics. 5th ed. New York, NY: Macmillan Publ. Co., Inc., 1975.

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

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.

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

Everything else you take

See Every Supplement That Interacts With Pacritinib

This page covers Aspen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pacritinib page lists 158 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 110 moderate · 40 minor.

From our pharmacist’s overview on the Pacritinib page

“Someone on pacritinib (Vonjo) is usually fighting myelofibrosis, and the supplements people reach for during cancer treatment, herbal blends, immune boosters, St. John's wort for mood, are where this list gets serious.”

Reviewed by 2 · Jul 18, 2026

Open the Pacritinib 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 Pacritinib, 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 Pacritinib 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

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

29 days ago today

Medication Pacritinib

Top half

#1,047 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 September 20, 2026. The Aspen and Pacritinib 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Aspen

What is 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 Pacritinib

What Is Pacritinib Used For?

Brand name: Vonjo

Vonjo (pacritinib) is used to treat adults with intermediate or high-risk myelofibrosis (MF) — a serious bone marrow disease — including primary MF and secondary MF that developed after polycythemia vera or essential thrombocythemia (other blood disorders). It is specifically approved for patients whose platelet count is below 50 × 10⁹/L (very low platelets), a group that has limited treatment options.

This approval is based on demonstrated reductions in spleen size. Continued approval may depend on results from confirmatory trials showing broader clinical benefit.

See full Pacritinib 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 Pacritinib, 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.

Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Goodman LS, Gilman A. The Pharmacological Basis of Therapeutics. 5th ed. New York, NY: Macmillan Publ. Co., Inc., 1975.
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 Pacritinib Together: Common Questions

Is it safe to take Aspen with Pacritinib?

We do not list a known interaction between Aspen and Pacritinib. 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 Aspen and Pacritinib combination checked?

Interactions in our licensed database are recorded against drug classes. Pacritinib is filed under 5 classifications, and Aspen has documented interactions with 3 drug classes — none of Pacritinib'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 — Pacritinib 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 Pacritinib interact with any supplements?

Yes. Pacritinib has documented interactions with 158 supplements in our database — Aspen is not one of them. The Pacritinib 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 Pacritinib drug information The full plain-English guide to this medication Pacritinib supplement interactions Every supplement checked against Pacritinib, 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 Pacritinib 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.