Herb & supplement monograph

Manaca Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated June 2026
What is this page for?

First and foremost: how Manaca interacts with medications. The heart of this page is the interaction list — every drug Manaca is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Manaca 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

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Interaction report

Drugs that interact with Manaca

0 medications have a known interaction with Manaca, graded by severity. Select any drug for the full evidence-based detail.

We don’t currently list any known drug interactions for Manaca. This doesn’t guarantee none exist — always confirm with your pharmacist before combining supplements with your medications.

Read The List Like a Pharmacist

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 Manaca combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Monograph

Manaca: Uses, Safety & Side Effects

Medically reviewed by · Reviewed June 2026 ·
The bottom line

Manaca (Brunfelsia uniflora) is a South American shrub traditionally used for arthritis, rheumatism, and skin problems. There is very little reliable human research to support these uses, and the plant belongs to the nightshade family and may be toxic, so caution is strongly advised. Talk to a pharmacist or doctor before using it.

Scientific name
Brunfelsia uniflora
Family
Solanaceae
Part used
Roots and bark; sometimes leaves
Common forms
Tincture, dried root, capsules, tea, homeopathic preparations
People commonly use it for
  • Joint pain and arthritis
  • Rheumatism
  • Skin conditions
  • As a diuretic
  • Inflammation

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

It belongs to the potentially toxic nightshade family and lacks safety testing in humans.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail
BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Manaca is a flowering shrub native to Brazil and other parts of tropical South America. It is part of the nightshade family (Solanaceae), the same plant family that includes tomatoes, peppers, and some toxic plants. Its showy flowers change color from purple to white, which is why related plants are sometimes nicknamed "yesterday, today, and tomorrow."

In traditional South American folk medicine, the roots and bark of manaca have been used to make teas, tinctures, and other preparations. People have traditionally turned to it for joint and muscle pain, swelling, and certain skin problems. Today it is sometimes sold as a tincture, capsule, or homeopathic remedy.

How it works

Manaca contains plant compounds that have been studied mainly in the laboratory. These include substances such as scopoletin (a coumarin) and various alkaloids and other compounds found in nightshade plants. Some of these have shown anti-inflammatory or pain-related effects in test-tube or animal experiments.

Because this research is early and not done in people, it is not clear whether manaca actually has these effects in the human body, or what doses might be needed. Any proposed benefits should be viewed as unproven.

Effectiveness

Does Manaca work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 1 use evaluated
1 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Manaca, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 1 condition — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Osteoarthritis
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral manaca for osteoarthritis, there is insufficient reliable information about the clinical effects of manaca 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

Manaca has not been well studied for safety in humans. As a member of the nightshade family, it may contain compounds that can be toxic, especially at higher doses. Some traditional reports describe effects on the nervous system, such as numbness, tingling, dizziness, or even more serious reactions when too much is taken.

People with existing health conditions, older adults, and children should be especially careful and should not use it without medical guidance. Pregnant and breastfeeding women should avoid manaca because there is no reliable safety data and a real possibility of harm. Always speak with a pharmacist or doctor before trying it.

Side effects

Because manaca is poorly studied, the full range of side effects is not known. Traditional and anecdotal reports suggest it may cause numbness or tingling, dizziness, drowsiness, nausea, or low energy, particularly if too much is used.

As a nightshade plant, larger amounts could potentially cause more serious reactions affecting the nervous system or heart. If you notice any unusual or severe symptoms after taking it, stop using it and seek medical care.

Dosing

There is no established or standardized dose for manaca. Because the plant may be toxic and has not been tested in proper human studies, safe dosing has not been determined.

If you choose to use a product that contains manaca, follow the directions on the label and do not exceed them. It is best to check with a pharmacist or doctor first, since the right amount, the quality of the product, and your own health all matter.

Pregnancy & Breastfeeding

Manaca & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

Manaca & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 1 sources that drive our Manaca monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing.

  1. Using Dietary Supplements Safely — NIH MedlinePlus Source
Keep reading

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.

Pharmacist Counseling Corner

Manaca: Common Questions

What is Manaca used for, and does it work?
People use Manaca for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Manaca interact with prescription medications?
We do not currently list any known drug interactions for Manaca. This does not guarantee that none exist, so always confirm with your pharmacist before combining it with your medications.
How are Manaca interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Manaca with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Manaca interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Manaca used for?
It is traditionally used for joint pain, arthritis, rheumatism, skin problems, and as a diuretic, but there is little scientific evidence that it works for any of these.
Is Manaca safe to take?
Its safety is not well known. Because it belongs to the nightshade family and may be toxic, it should be used cautiously and only after talking with a healthcare professional.
Can I use Manaca during pregnancy or while breastfeeding?
No. There is not enough safety information, and the plant may be harmful, so it is best to avoid Manaca during pregnancy and breastfeeding.
How is Manaca taken?
It is most often used as a tincture, dried root, tea, capsule, or homeopathic preparation, but there is no standard dose, so follow the product label and ask a pharmacist.

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

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