Drug & supplement interaction

Desert Parsley + Guanethidine Monosulfate

Guanethidine Monosulfate brand names: Ismelin, Isimil.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Desert Parsley and Guanethidine Monosulfate 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

Desert Parsley and Guanethidine Monosulfate

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 Guanethidine Monosulfate and Desert Parsley 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Desert Parsley at all — not against Guanethidine Monosulfate, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Desert Parsley safety at a glance

Desert Parsley overall Use caution Limited human safety data and a known risk of a measles-like skin rash in some users.
Pregnancy Avoid Not enough safety data; avoid use during pregnancy.
Breastfeeding Avoid Not enough safety data; avoid while breastfeeding.

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

Still wondering about combining Guanethidine Monosulfate and Desert Parsley? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Everything else you take

See Every Supplement That Interacts With Guanethidine Monosulfate

This page covers Desert Parsley only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guanethidine Monosulfate page lists 137 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 21 minor.

From our pharmacist’s overview on the Guanethidine Monosulfate page

“Guanethidine monosulfate (Ismelin) is a forceful older drug for severe high blood pressure, and its interaction list warrants genuine care. Nearly all 137 supplements and herbs on file pull blood pressure one way or the other, either adding to the drug's effect and risking dizziness and faints, or pushing pressure back up and undoing t…”

Reviewed by 2 · Jul 18, 2026

Open the Guanethidine Monosulfate interaction page

How much people look this up

Where Desert Parsley and Guanethidine Monosulfate 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 Desert Parsley
Top half

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

29 days ago today
Medication Guanethidine Monosulfate
Steady interest

#1,631 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. Desert Parsley is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Desert Parsley reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Desert Parsley and Guanethidine Monosulfate records this page draws on were last updated June 22, 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 Desert Parsley

What is Desert Parsley?

  • Respiratory infections and colds
  • Cough and congestion
  • Flu-like illness
  • Immune support
  • Sore throat

Desert Parsley (Lomatium dissectum) is a root used in Native American and Western herbal traditions, mainly for colds, coughs, and respiratory infections. Modern scientific evidence in humans is very limited, and it can cause a widespread skin rash in some people, so use it cautiously and talk with your pharmacist or doctor first.

Lomatium dissectum · Apiaceae · Root · Tincture, capsules, dried root, tea, glycerite extract

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

Desert Parsley: dosing

There is no established standard dose for Desert Parsley. Traditional use varies widely depending on the form, whether it is a tincture, capsule, or tea.Because a safe and effective dose has not been defined in research, follow the directions on the product label and do not exceed them.

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

Read the full Desert Parsley monograph & all interactions
Keep checking

Other Drugs & Desert Parsley

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Desert Parsley References

The 1 sources that drive our Desert Parsley monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Desert Parsley is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Using Dietary Supplements Wisely — NIH National Center for Complementary and Integrative Health (NCCIH) Source

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 Desert Parsley and Guanethidine Monosulfate Together: Common Questions

Is it safe to take Desert Parsley with Guanethidine Monosulfate?
We do not list a known interaction between Desert Parsley and Guanethidine Monosulfate. 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.
Does Guanethidine Monosulfate interact with any supplements?
Yes. Guanethidine Monosulfate has documented interactions with 137 supplements in our database — Desert Parsley is not one of them. The Guanethidine Monosulfate interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Guanethidine Monosulfate and Desert Parsley?

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.