Drug & supplement interaction

Cypress + Peginterferon alfa-2b

Peginterferon alfa-2b brand names: Peg-Intron, ViraferonPeg.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Cypress and Peginterferon alfa-2b 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

Cypress and Peginterferon alfa-2b

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 Peginterferon alfa-2b and Cypress 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.

Cypress safety at a glance

Cypress overall Use caution Often used externally or in aromatherapy; the essential oil should not be swallowed and human safety data are limited.

Pregnancy Avoid Not enough safety information, so it is best to avoid use during pregnancy.

Breastfeeding Avoid Not enough safety information, so it is best to avoid use while breastfeeding.

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

Still wondering about combining Peginterferon alfa-2b and Cypress? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Peginterferon alfa-2b

Interactions in our licensed database are recorded against drug classes, not just single drug names. Peginterferon alfa-2b is filed under a single classification — hepatotoxic drugs. Cypress has documented interactions with 1 drug class — the most serious being anticoagulant/antiplatelet drugs (moderate) — and none of Peginterferon alfa-2b’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

Cypress Does Interact With Other Medications

Cypress has 122 moderate known drug interactions in our database — Peginterferon alfa-2b isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 No known interaction 2,708 (incl. Peginterferon alfa-2b)

Taking anything else?

Check Another of Your Medications Against Cypress

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

What to actually watch for

What Cypress Itself Has Been Linked To

This is not an interaction — nothing below involves Peginterferon alfa-2b. It is the side-effect record for Cypress on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Cypress, this list is the first place to look.

A skin rash Additional detail
“Airborne cypress pollen is a common cause of allergy-related respiratory and ocular symptoms in some people. A case of allergic contact dermatitis to the resin-impregnated leaves of a cypress tree has occurred in a patient with a history of cutaneous reactions to adhesive bandages, likely due to a cross-sensitivity with colophonium.”

Cypress · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).
5 sources cited

46912. Geller-Bernstein, C., Waisel, Y., and Lahoz, C. Environment and sensitization to cypress in Israel. Allerg.Immunol.(Paris) 2000;32(3):92-93.

46915. Papa, G., Romano, A., Quaratino, D., Di Fonso, M., Viola, M., Artesani, M. C., Sernia, S., Di Gioacchino, M., and Venuti, A. Prevalence of sensitization to Cupressus sempervirens: a 4-year retrospective study. Sci.Total Environ. 4-10-2001;270(1-3):83-87. PubMed

46925. Togawa, A., Panzani, R. C., Garza, M. A., Kishikawa, R., Goldblum, R. M., and Midoro-Horiuti, T. Identification of italian cypress (Cupressus sempervirens) pollen allergen Cup s 3 using homology and cross-reactivity. Ann.Allergy Asthma Immunol. 2006;97(3 PubMed

46930. De Luca, A., Graziani, E., Anticoli, S., Simeoni, S., Terzano, C., and Mannino, F. Respiratory allergy to Cupressus sempervirens in Rome. Allergol.Immunopathol.(Madr.) 1997;25(5):229-232.

106005. Samaran Q, Clark E, Dereure O, Raison-Peyron N. Allergic contact dermatitis to Cupressus sempervirens resin and cross-reaction with colophonium. Contact Dermatitis 2020;83(1):33-35.

Everything above comes from the Natural Medicines adverse-effect record for Cypress — expand a row for the licensed statement it rests on. We haven’t matched Peginterferon alfa-2b 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 Peginterferon alfa-2b.

Everything else you take

See Every Supplement That Interacts With Peginterferon alfa-2b

This page covers Cypress only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Peginterferon alfa-2b page lists 38 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), Ashwagandha (moderate) and Black Cohosh (moderate).

By severity: 3 major · 35 moderate.

From our pharmacist’s overview on the Peginterferon alfa-2b page

“Someone taking peginterferon alfa-2b (Peg-Intron) is usually treating hepatitis C, so the liver is already the organ under strain, and all 38 supplement interactions on file for this drug pile additional liver stress on top of it. That earns genuine caution.”

Reviewed by 2 · Jul 18, 2026

Open the Peginterferon alfa-2b interaction page

One more smart check

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

We hold 13 real supplement products containing Cypress, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cypress. Even though Cypress itself has no known interaction with Peginterferon alfa-2b, 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 Cypress and Peginterferon alfa-2b 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 Cypress

Top half

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

29 days ago today

Medication Peginterferon alfa-2b

Steady interest

#2,614 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 Cypress reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Cypress and Peginterferon alfa-2b 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 Cypress

What is Cypress?

Circulation and varicose veins
Coughs and respiratory complaints
Excess sweating
Skin and minor wounds
Aromatherapy for relaxation

Cypress comes from the Mediterranean cypress tree and is most often used as an essential oil in aromatherapy or skin care, and traditionally for circulation and respiratory complaints. High-quality human evidence for these uses is very limited, so it should not replace proven treatments. The essential oil is for external use only and should be diluted, and you should talk with your pharmacist or doctor before using it.

Cupressus sempervirens · Cupressaceae · Cones (galbuli), leaves/needles, and essential oil · Essential oil, extracts, capsules, and dried plant material

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

Cypress: dosing

There is no standardized or well-established dose for cypress. Products vary widely in strength and form, so the right amount depends on how it is being used.For essential oil used on the skin, it should always be diluted in a carrier oil rather than applied straight. Do not take cypress essential oil by mouth.

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

Read the full Cypress monograph & all interactions

Medication

About Peginterferon Alfa-2b (PEG-Intron)

What Is Peginterferon Alfa-2b (PEG-Intron) Used For?

Brand names: Peg-Intron, ViraferonPeg

Peginterferon alfa-2b is used alone or in combination with ribavirin (a medication) to treat chronic (long-term) hepatitis C infection (swelling of the liver caused by a virus) in people who show signs of liver damage and who have not been treated with interferon alpha (medication similar to peginterferon alfa-2b) in the past. Peginterferon alfa-2b is in a class of medications called interferons. Peginterferon alfa-2b is a combination of interferon and polyethylene glycol, which helps the interferon stay active in your body for a longer period of time. Peginterferon alpha-2b works by decreasing the amount of hepatitis C virus (HCV) in the body. Peginterferon alfa-2b may not cure hepatitis C or prevent you from developing complications of hepatitis C such as cirrhosis (scarring) of the liver, liver failure, or liver cancer. Peginterferon alfa-2b may not prevent the spread of hepatitis C to other people.

See full Peginterferon Alfa-2b (PEG-Intron) drug information

Keep checking

Other Drugs & Cypress

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

0Major

122Moderate

0Minor

2,707No known interaction

122 Moderate 2,707 No interaction

Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Cypress page.

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Cypress list.

See the full Cypress interactions page

See every supplement checked against Peginterferon alfa-2b, ranked by severity

Evidence & sources

Cypress References

The 7 references that drive our Cypress 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.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Geller-Bernstein, C., Waisel, Y., and Lahoz, C. Environment and sensitization to cypress in Israel. Allerg.Immunol.(Paris) 2000;32(3):92-93.
Papa, G., Romano, A., Quaratino, D., Di Fonso, M., Viola, M., Artesani, M. C., Sernia, S., Di Gioacchino, M., and Venuti, A. Prevalence of sensitization to Cupressus sempervirens: a 4-year retrospective study. Sci.Total Environ. 4-10-2001;270(1-3):83-87. PubMed
Togawa, A., Panzani, R. C., Garza, M. A., Kishikawa, R., Goldblum, R. M., and Midoro-Horiuti, T. Identification of italian cypress (Cupressus sempervirens) pollen allergen Cup s 3 using homology and cross-reactivity. Ann.Allergy Asthma Immunol. 2006;97(3 PubMed
De Luca, A., Graziani, E., Anticoli, S., Simeoni, S., Terzano, C., and Mannino, F. Respiratory allergy to Cupressus sempervirens in Rome. Allergol.Immunopathol.(Madr.) 1997;25(5):229-232.
Ulusal BG, Arikan S, Durusoy C. Anticoagulant effect of Cupressus sempervirens. Phytother Res. 2007 Nov;21(11):1116.
Samaran Q, Clark E, Dereure O, Raison-Peyron N. Allergic contact dermatitis to Cupressus sempervirens resin and cross-reaction with colophonium. Contact Dermatitis 2020;83(1):33-35.

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 Cypress and Peginterferon alfa-2b Together: Common Questions

Is it safe to take Cypress with Peginterferon alfa-2b?

We do not list a known interaction between Cypress and Peginterferon alfa-2b. 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 Cypress and Peginterferon alfa-2b combination checked?

Interactions in our licensed database are recorded against drug classes. Peginterferon alfa-2b is filed under 1 classification, and Cypress has documented interactions with 1 drug class — none of Peginterferon alfa-2b'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 Cypress interact with any other medications?

Yes. Cypress has 122 documented drug interactions in our database — Peginterferon alfa-2b 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 Peginterferon alfa-2b interact with any supplements?

Yes. Peginterferon alfa-2b has documented interactions with 38 supplements in our database — Cypress is not one of them. The Peginterferon alfa-2b 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

Cypress monograph Uses, safety profile, and every drug interaction in one place Peginterferon Alfa-2b (PEG-Intron) drug information The full plain-English guide to this medication Peginterferon alfa-2b supplement interactions Every supplement checked against Peginterferon alfa-2b, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Peginterferon alfa-2b and Cypress?

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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.