Osha Drug Interactions, Uses, Effectiveness, Safety & More
What is this page for?
First and foremost: how Osha interacts with medications. The heart of this page is the interaction list — every drug Osha is known to interact with, and how serious each one is.
But these pages have grown well beyond that into a full monograph — what Osha is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy
Check Osha against your medication
Add one medicationDrugs that interact with Osha
0 medications have a known interaction with Osha, graded by severity. Select any drug for the full evidence-based detail.
We don’t currently list any known drug interactions for Osha. This doesn’t guarantee none exist — always confirm with your pharmacist before combining supplements with your medications.
What Severity, Likelihood & Evidence Mean
Severity — How Serious It Can Be
- Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
- Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
- Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
- No known interaction. Checked against our sources with nothing documented — not the same as proven safety.
Likelihood — How Well It’s Documented
- Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
- Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
- Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
- Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Where This Data Comes From
- Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
- Each drug listed above links to the full report for that exact Osha combination — clinical detail, likelihood, evidence level, and citations.
- Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Osha: Uses, Safety & Side Effects
Osha is a root from a wild mountain plant native to the western United States and Mexico, traditionally used by Native American and Hispanic communities for coughs, colds, and sore throats. Solid human research is lacking, so its benefits remain unproven, and it should be avoided during pregnancy and breastfeeding. Talk to your pharmacist or doctor before trying it.
- Scientific name
- Ligusticum porteri
- Family
- Apiaceae
- Part used
- Root
- Common forms
- Tea, tincture, capsules, lozenges, chewed raw root
- Cough and sore throat
- Respiratory infections and colds
- Immune support
- Digestive upset
- Bronchitis and congestion
Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.
Limited safety data exist, and wild osha can be confused with poisonous look-alike plants.
When used orally. Osha has been used to stimulate menstruation and is reported to have abortifacient activity; contraindicated.
Read the full pregnancy detailInsufficient reliable information available; avoid using.
Read the full breastfeeding detailPregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Overview
Osha (Ligusticum porteri) is a plant in the carrot and parsley family that grows in the high mountains of the western United States and Mexico. The part most people use is the root, which has a strong, spicy, celery-like smell.
Osha has a long history of use in Native American and Hispanic herbal traditions. People have used it for coughs, sore throats, colds, and other breathing problems, often by chewing the raw root or brewing it into tea.
Today osha is sold as a tea, tincture, capsule, lozenge, or dried root. Because it is mostly gathered from the wild and is difficult to grow on farms, supply can be limited and quality can vary.
How it works
Osha root contains a variety of plant compounds, including volatile oils (which give it its strong smell), phthalides, and other substances. In laboratory tests, some of these compounds have shown antioxidant or antimicrobial activity.
Supporters suggest osha may help soothe the throat and loosen mucus, but these ideas are mostly based on traditional use and early lab research, not on well-designed human studies.
In short, the proposed mechanisms are plausible but unproven. We do not have strong evidence showing exactly how osha affects the human body.
Does Osha work?
How to read these evidence grades
Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.
For Osha, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.
Also studied for 2 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Dyspepsia
Although there has been interest in using oral osha for dyspepsia, there is insufficient reliable information about the clinical effects of osha for this purpose.
Insufficient Reliable Evidence To Rate HIV/AIDS
Although there has been interest in using oral osha for HIV/AIDS, there is insufficient reliable information about the clinical effects of osha for this purpose.
Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.
Safety & precautions
Osha has been used for generations, but it has not been carefully studied for safety in modern research. One important concern is that osha grows in the wild alongside poison hemlock and water hemlock, which are highly toxic and can look similar. Buying from a trusted, reputable supplier helps lower this risk.
People with liver problems, kidney problems, or bleeding concerns should be cautious and check with a healthcare provider first. People allergic to plants in the carrot/parsley family (such as celery, carrot, or parsley) may also react to osha.
Pregnancy: Osha has traditionally been avoided during pregnancy, and there is no reliable safety data, so it should be avoided. Breastfeeding: There is not enough information to know if osha is safe while nursing, so it is best to avoid it.
Side effects
Because osha has not been well studied, its full side effect profile is not known. Reported or possible effects include stomach upset and allergic reactions, especially in people sensitive to related plants.
The most serious risk usually comes from misidentification—taking a toxic look-alike plant by mistake. Stop using osha and seek medical care if you have signs of an allergic reaction, such as a rash, swelling, or trouble breathing.
Dosing
There is no established standard dose for osha. The right amount depends on the form (tea, tincture, capsule, or lozenge) and the product's strength.
If you choose to use osha, follow the directions on the product label and do not exceed them. Because quality and potency vary between products, it is wise to talk with a pharmacist or doctor before starting, especially if you take other medicines or have a health condition.
Osha & Pregnancy
Osha & Breastfeeding
© 2026 Therapeutic Research Center
Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center
References & further reading
The 2 references that drive our Osha 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.
- McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
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.
Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Brands that make products with Osha
50 brands in our database make a supplement containing Osha.
Supplement products with Osha
336 products in our database contain Osha. Open any to see its full ingredient list and every drug interaction we check.
Osha: Common Questions
What is Osha used for, and does it work?
Does Osha interact with prescription medications?
How are Osha interactions rated?
Is it safe to take Osha with my medications?
Where does this Osha interaction information come from?
What is Osha used for?
Is Osha safe to take?
Can I take Osha while pregnant or breastfeeding?
How is Osha usually taken?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Products that contain Osha
A rotating sample of real supplements in our database that list Osha — open any to see its full ingredients and every drug interaction we check.
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