Drug & supplement interaction

Aspen + Interferon Beta-1a

Interferon Beta-1a brand names: Rebif, Avonex.

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 Interferon Beta-1a 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 Interferon Beta-1a

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 Interferon Beta-1a 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 Interferon Beta-1a and Aspen? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Interferon Beta-1a

Interactions in our licensed database are recorded against drug classes, not just single drug names. Interferon Beta-1a is filed under 2 classifications — photosensitizing drugs, hepatotoxic 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 Interferon Beta-1a’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 — Interferon Beta-1a 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. Interferon Beta-1a)

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 Interferon Beta-1a. 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 haven’t matched Interferon Beta-1a to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Interferon Beta-1a.

Everything else you take

See Every Supplement That Interacts With Interferon Beta-1a

This page covers Aspen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Beta-1a page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Beta-1a page

“Siberian cocklebur, an herb tied to documented cases of liver failure, is the first name to know for anyone injecting interferon beta-1a (Rebif, Avonex) for multiple sclerosis. Interferon beta-1a can strain the liver on its own, which is why prescribers order routine liver blood tests, and 38 of the 57 supplements on file carry that sa…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Beta-1a 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 Interferon Beta-1a, 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 Interferon Beta-1a 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

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

29 days ago today

Medication Interferon Beta-1a

Steady interest

#1,920 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 Interferon Beta-1a 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 Interferon Beta-1a Intramuscular Injection

What Is Interferon Beta-1a Intramuscular Injection Used For?

Brand names: Rebif, Avonex

Interferon beta-1a intramuscular injection is used to treat adults with various forms of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control) including:
- clinically isolated syndrome (CIS; nerve symptom episodes that last at least 24 hours),
- relapsing-remitting forms (course of disease where symptoms flare up from time to time), or
- secondary progressive forms (course of disease where relapses occur more often).
Interferon beta-1a is in a class of medications called immunomodulators. It works by decreasing inflammation and preventing nerve damage that may cause symptoms of multiple sclerosis.

Most-Reported Side Effects for Interferon Beta-1a

From FAERS, the FDA’s public side-effect reporting system (192,069 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Multiple sclerosis relapse 15,851 reports

Influenza like illness 13,253 reports

Fatigue 11,554 reports

Fall 10,604 reports

Multiple sclerosis 9,358 reports

See full Interferon Beta-1a Intramuscular Injection 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 Interferon Beta-1a, 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 Interferon Beta-1a Together: Common Questions

Is it safe to take Aspen with Interferon Beta-1a?

We do not list a known interaction between Aspen and Interferon Beta-1a. 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 Interferon Beta-1a combination checked?

Interactions in our licensed database are recorded against drug classes. Interferon Beta-1a is filed under 2 classifications, and Aspen has documented interactions with 3 drug classes — none of Interferon Beta-1a'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 — Interferon Beta-1a 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 Interferon Beta-1a interact with any supplements?

Yes. Interferon Beta-1a has documented interactions with 57 supplements in our database — Aspen is not one of them. The Interferon Beta-1a 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 Interferon Beta-1a Intramuscular Injection drug information The full plain-English guide to this medication Interferon Beta-1a supplement interactions Every supplement checked against Interferon Beta-1a, 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 Interferon Beta-1a and Aspen?

Our pharmacists answer your medication & supplement questions — free.

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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.