Drug & supplement interaction

Shepherd's Purse + Methaqualone

Methaqualone brand name: Quaalude.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Shepherd's Purse has a moderate interaction with Methaqualone. Theoretically, concomitant use with drugs with sedative properties may cause additive effects and side effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Shepherd's Purse and Methaqualone

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CNS DEPRESSANTS

Why this applies to Methaqualone

Methaqualone falls under CNS DEPRESSANTS — the group Shepherd's Purse interacts with.

Theoretically, concomitant use with drugs with sedative properties may cause additive effects and side effects.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Methaqualone (Quaalude) is a powerful sedative that calms your central nervous system, which is why it makes people feel drowsy, relaxed, and slow to react. The concern here is simple: shepherd's purse has been reported in some traditional and animal sources to have its own mild calming or sedative-like effects. Stack that on top of a drug like methaqualone and you could, in theory, feel extra sleepy, foggy, or unsteady, with slower breathing and worse coordination.

That said, this warning is theoretical and based on how these things work, not on solid human studies. We don't have good proof it actually causes a problem. Still, because methaqualone is so strongly sedating on its own, it's worth running this combination past your pharmacist or doctor before mixing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Shepherd's Purse Also Interacts With Other Medications

Shepherd's Purse has 263 moderate known drug interactions in our database — the Methaqualone one above is one of them. If you take anything else, check it against the full list below.

Moderate 263 No known interaction 2,567 (incl. Methaqualone)
Taking anything else?

Check Another of Your Medications Against Shepherd's Purse

Covers the 2,830 medications we’ve checked against Shepherd's Purse. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Methaqualone

This page covers Shepherd's Purse only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methaqualone page lists 95 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 73 moderate · 15 minor.

From our pharmacist’s overview on the Methaqualone page

“Methaqualone (Quaalude) is a heavy sedative, and the people who take it for sleep are often the same ones drawn to calming supplements, which is exactly why this page deserves a wary read. Seventy-eight of its 95 listed ingredients add their own sedation, kava among the strongest, and the worst pairings can suppress breathing, not just…”

Reviewed by 2 · Jul 18, 2026

Open the Methaqualone interaction page

One more smart check

Taking Shepherd's Purse as Part of a Dietary Supplement Product? Check It for Interactions

We hold 73 real supplement products containing Shepherd's Purse, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Shepherd's Purse. Your product may carry other ingredients that interact with Methaqualone too, on top of Shepherd's Purse — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Shepherd's Purse and Methaqualone 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 Shepherd's Purse
Top half

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

29 days ago today
Medication Methaqualone
Steady interest

#2,143 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.

Supplement

About Shepherd's Purse

What is Shepherd's Purse?

Shepherd's Purse
  • Heavy or prolonged menstrual bleeding
  • Minor bleeding (nosebleeds, wounds)
  • Mild diuretic
  • Digestive complaints
  • After-childbirth bleeding (traditional)

Shepherd's purse is a traditional herb most often used to help slow heavy menstrual bleeding and other minor bleeding, but solid human research is very limited. Because it may affect blood clotting, blood pressure, and the uterus, it should be avoided during pregnancy and used cautiously under professional guidance.

Read the full Shepherd's Purse monograph & all interactions
Keep checking

Other Drugs & Shepherd's Purse

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

0Major
263Moderate
0Minor
2,566No known interaction
263 Moderate 2,566 No interaction
Moderate

263 interactions

Showing 60 of 263 moderate interactions — see all 263 on the Shepherd's Purse page.

No interaction 2,566 drugs checked — show the list

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

Showing the 60 most looked-up of 2,566 medications checked with no known interaction — see the full Shepherd's Purse list.

See the full Shepherd's Purse interactions page
See every supplement checked against Methaqualone, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Shepherd's Purse monograph › Uses, safety, and every drug interaction in one place Methaqualone supplement interactions › Every supplement checked against Methaqualone, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Shepherd's Purse and Methaqualone Together: Common Questions

Can you take Shepherd's Purse with Methaqualone?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Shepherd's Purse and Methaqualone interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Methaqualone and Shepherd's Purse?

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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.