Drug & supplement interaction

Calea Zacatechichi + Ulipristal Acetate

Ulipristal Acetate brand name: Ella.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Calea Zacatechichi and Ulipristal Acetate 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Calea Zacatechichi and Ulipristal Acetate

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 Ulipristal Acetate and Calea Zacatechichi 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.

Calea Zacatechichi safety at a glance

Calea Zacatechichi overall Use caution It has a long folk-use history but little modern safety data, and it can cause nausea and vomiting.
Pregnancy Avoid There is no reliable safety data, so it is best avoided during pregnancy.
Breastfeeding Avoid There is no reliable safety data, so it is best avoided while breastfeeding.

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

Still wondering about combining Ulipristal Acetate and Calea Zacatechichi? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Ulipristal Acetate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Ulipristal Acetate is filed under 3 classifications — contraceptive drugs, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Calea Zacatechichi has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (minor) and cns depressants (minor) — and none of Ulipristal Acetate’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

Calea Zacatechichi Does Interact With Other Medications

Calea Zacatechichi has 334 minor known drug interactions in our database — Ulipristal Acetate isn’t one of them. If you take anything else, check it against the full list below.

Minor 334 No known interaction 2,496 (incl. Ulipristal Acetate)
Taking anything else?

Check Another of Your Medications Against Calea Zacatechichi

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

What to actually watch for

No Interaction Found — But Data Suggests Calea Zacatechichi and Ulipristal Acetate May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Nausea reported in 7.8% of FDA reports for Ulipristal Acetate Additional detail

    Calea Zacatechichi

    “Observations in healthy volunteers indicate that Calea zacatechichi is bitter tasting and can cause nausea, vomiting, and retching.”

    Calea Zacatechichi · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 23602. Mayagoitia, L., Diaz, J. L., Contreras, C. M. Psychopharmacologic analysis of an alleged oneirogenic plant: Calea zacatechichi. J Ethnopharmacol. 1986;18:229-243. PubMed

    Ulipristal Acetate

    Listed in the ADVERSE REACTIONS section of the FDA label for Ulipristal Acetate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Calea Zacatechichi but not commonly for Ulipristal Acetate: drowsiness and vomiting.

Effects for Ulipristal Acetate come from the ADVERSE REACTIONS section of its FDA label; effects for Calea Zacatechichi come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 498 voluntary FDA FAERS reports for Ulipristal Acetate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Ulipristal Acetate

This page covers Calea Zacatechichi only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ulipristal Acetate page lists 158 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 107 moderate · 48 minor.

From our pharmacist’s overview on the Ulipristal Acetate page

“St. John's wort worries me most with ulipristal acetate (Ella), the emergency contraceptive that gets exactly one chance to work.”

Reviewed by 2 · Jul 18, 2026

Open the Ulipristal Acetate interaction page

One more smart check

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

We hold 21 real supplement products containing Calea Zacatechichi, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Calea Zacatechichi. Even though Calea Zacatechichi itself has no known interaction with Ulipristal Acetate, 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 Calea Zacatechichi and Ulipristal Acetate 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 Calea Zacatechichi
Steady interest

#1,201 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ulipristal Acetate
Steady interest

#2,175 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 Calea Zacatechichi reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Calea Zacatechichi and Ulipristal Acetate 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 .
Supplement

About Calea Zacatechichi

What is Calea Zacatechichi?

  • Promoting vivid or lucid dreams
  • Sleep and relaxation
  • Digestive upset
  • Fever
  • Traditional ritual use

Calea zacatechichi, often called 'dream herb,' is a Mexican plant traditionally used to encourage vivid dreams and to treat digestive complaints and fever. Human research is very limited, so its benefits are not well proven, and its safety has not been carefully studied. It tastes very bitter, can cause nausea, and should be avoided during pregnancy and breastfeeding.

Calea ternifolia · Asteraceae · Leaves and flowering tops (dried) · Dried leaf tea, capsules, tincture/liquid extract, and smoked dried leaf

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

Calea Zacatechichi: dosing

There is no established or standardized dose for Calea zacatechichi. The amount of active compounds can vary a lot from product to product, which makes safe dosing hard to judge.If you choose to use it, follow the directions on the product label and do not exceed them.

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

Read the full Calea Zacatechichi monograph & all interactions
Medication

About Ulipristal

What Is Ulipristal Used For?

Brand name: Ella

Ella (ulipristal acetate) is used to prevent pregnancy after unprotected sex or when another form of birth control has failed or was used incorrectly. It must be taken as soon as possible, within 5 days (120 hours) of that event.

Ella is intended for occasional, emergency use only — it is not a substitute for regular, ongoing contraception.

See full Ulipristal drug information
Keep checking

Other Drugs & Calea Zacatechichi

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

0Major
0Moderate
334Minor
2,495No known interaction
334 Minor 2,495 No interaction
Minor

334 interactions

Showing 60 of 334 minor interactions — see all 334 on the Calea Zacatechichi page.

No interaction 2,495 drugs checked — show the list

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

Showing the 60 most looked-up of 2,495 medications checked with no known interaction — see the full Calea Zacatechichi list.

See the full Calea Zacatechichi interactions page
See every supplement checked against Ulipristal Acetate, ranked by severity
Evidence & sources

Calea Zacatechichi References

The 2 references that drive our Calea Zacatechichi 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.

  1. Mayagoitia, L., Diaz, J. L., Contreras, C. M. Psychopharmacologic analysis of an alleged oneirogenic plant: Calea zacatechichi. J Ethnopharmacol. 1986;18:229-243. PubMed
  2. Roman, Ramos R., Alarcon-Aguilar, F., Lara-Lemus, A., and Flores-Saenz, J. L. Hypoglycemic effect of plants used in Mexico as antidiabetics. Arch.Med.Res 1992;23:59-64.

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 Calea Zacatechichi and Ulipristal Acetate Together: Common Questions

Is it safe to take Calea Zacatechichi with Ulipristal Acetate?
We do not list a known interaction between Calea Zacatechichi and Ulipristal Acetate. 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.
Do Calea Zacatechichi and Ulipristal Acetate have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Calea Zacatechichi and Ulipristal Acetate combination checked?
Interactions in our licensed database are recorded against drug classes. Ulipristal Acetate is filed under 3 classifications, and Calea Zacatechichi has documented interactions with 2 drug classes — none of Ulipristal Acetate'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 Calea Zacatechichi interact with any other medications?
Yes. Calea Zacatechichi has 334 documented drug interactions in our database — Ulipristal Acetate 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 Ulipristal Acetate interact with any supplements?
Yes. Ulipristal Acetate has documented interactions with 158 supplements in our database — Calea Zacatechichi is not one of them. The Ulipristal Acetate 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

Calea Zacatechichi monograph Uses, safety profile, and every drug interaction in one place Ulipristal drug information The full plain-English guide to this medication Ulipristal Acetate supplement interactions Every supplement checked against Ulipristal Acetate, 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Ulipristal Acetate and Calea Zacatechichi?

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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.