Herb Profile

Guayusa

Ilex guayusa

Guayusa (Ilex guayusa) carries a Grade C rating — limited evidence.

Last reviewed: 3 sources citedReport a correctionProfile-wide ·C Limited

Use extra caution Caffeine containing herb; may worsen insomnia, anxiety, palpitations, reflux, and blood pressure in sensitive users. Details

Evidence
Limited Evidence
Typical onset
Varies by prep
Safety rating
High caution
Best for
Antioxidant, Stress resilience
Avoid / review if
Uncontrolled Hypertension, Arrhythmia, Severe Anxiety/Insomnia
Guayusa monograph visual
Generated profile category visual

At a glance

From this profile's structured data
Evidence
Grade C
Safety
Caffeine-containing herb; may worsen insomnia, anxiety, palpitations, reflux, and blood pressure in sensitive users.
Profile context
antioxidant
Next steps

Continue reading

Safety

Safety & Cautions

Caffeine containing herb; may worsen insomnia, anxiety, palpitations, reflux, and blood pressure in sensitive users.

High caution

Caution level: High. Multiple caution categories apply, or the record uses avoid/contraindication language.

  • Stimulant-Like ProfileStimulant-like or activating caution language is present.
  • Pregnancy/Breastfeeding CautionPregnancy or breastfeeding caution language is present.
Detailed safety fields

Pregnancy, breastfeeding, and contraindications

  • Uncontrolled Hypertension
  • Arrhythmia
  • Severe Anxiety/Insomnia
  • Pregnancy/Breastfeeding Caution
  • And Stimulant Sensitivity.
  • Additive Effects With Caffeine
  • Stimulants
  • Theophylline
  • Decongestants
  • And Stimulant Medications.

Safety classifications

  • Stimulant-Like Profile: Stimulant-like or activating caution language is present.
  • Pregnancy/Breastfeeding Caution: Pregnancy or breastfeeding caution language is present.

Full safety note

  • Caffeine containing herb; may worsen insomnia, anxiety, palpitations, reflux, and blood pressure in sensitive users.

Safety labels

  • Stimulant-Like Profile
  • Pregnancy/Breastfeeding Caution

Evidence-based safety

Caution when combined

Severity and certainty are shown separately. A high-priority caution can still be theoretical: these pairings are screened from shared contraindication mechanisms and are not automatically documented clinical interactions. Provenance identifies the source fields that produced each flag; it does not upgrade the certainty of the pairwise claim.

Evidence

Evidence Summary

Evidence lens

Read as directional context, not settled clinical proof.

LimitedLimited Evidence

Human clinical evidence: Present in source signals

Mechanistic / preclinical: Mechanism mappedOxidative Stress Modulation

Research maturity: Emerging researchLong Term Human Evidence May Be Limited.

Safety boundary: Safety note availableCaffeine containing herb; may worsen insomnia, anxiety, palpitations, reflux, and blood pressure in sensitive users.

This profile cites 3 human studies.

Study design details
Evidence Grade

Grade C: Limited Evidence

Evaluation of methodological rigor, population reach, and evidence alignment.

Design Match
Randomized controlled trial
Risk of Bias
Low
Consistency
Not assessed
Strongest recorded design is a randomized controlled trial, drawn from 2 recorded studies, 1 in people.
How evidence grades work

Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.

Strong
Multiple RCTs, consistent direction, adequate effect size
Moderate
Some RCTs or consistent observational data in humans
Preliminary / Mixed
Animal or in-vitro only, or conflicting human data
Traditional / Theoretical
Traditional use only; no controlled human trials
Clinical Study Summaries (3)1 human evidence source · 1 human trial · Participant totals not consistently reported · Consistency not yet classifiable

Filter by study class

Showing 3 of 3 studies.

What the evidence actually shows

This table contains 3 structured sources, including 1 human evidence source; 1 is a human trial. A reliable participant total cannot be calculated because sample size is not consistently structured in the cited sources. Source-to-conclusion relationships are not classified in this structured set, so consistency is not yet classifiable.

Profile-wide evidence grade: see the profile grade above · Confidence: not separately assigned

What would change our conclusion?

Larger, well-controlled human trials using comparable populations, doses, preparations, and clinically meaningful outcomes could materially strengthen or weaken this conclusion. Replication in a different population or a high-quality synthesis resolving current disagreement could also materially change confidence.

StudyDesignNDoseDurationPopulationOutcomeResult & magnitudeSource

Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance

La Monica MB et al. · Nutrients · 2023

Background
Randomized controlled trial

Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well.

PubMed

A critical review of the composition and history of safe use of guayusa: a stimulant and antioxidant novel food

Wise G et al. · Crit Rev Food Sci Nutr · 2020

Background
Narrative review

Summarizes selected literature without the full prespecified search and selection methods of a systematic review.

PubMed

Evaluation of Ilex guayusa and Piper marginatum Extract Cytotoxicity on Human Dental Pulp Mesenchymal Stem Cells

Sequeda-Castañeda LG et al. · Dent J (Basel) · 2024

Background
Other / unclear

The study design is not yet classified clearly enough to infer its place in the evidence hierarchy.

PubMed

Dosing & Timing

No standardized dose
Preparation specific; use standardized product label for Use moderate brewed preparations or products with disclosed caffeine content and require source backed dosage review before therapeutic claims.
How Guayusa works

Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.

Mechanism Pathway — How Guayusa Works

How Guayusa WorksGuayusa acts on biological target pathways via antioxidant, leading to antioxidant efct.GuayusaBiological TargetBiological pathwayAntioxidantAntioxidant EfctCell protectionMitochondrialBiogenesis
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways

Preclinical pathways. Proposed mechanisms from in vitro and animal research; these do not confirm clinical outcomes in humans.

  • Oxidative Stress Modulation

Active Compounds

Key constituents studied in Guayusa, with full pharmacology and safety profiles.

Compare related active botanicals

Explore botanicals with similar chemistry, effects, or safety considerations in the Botanical Activity Atlas.

Guides that use Guayusa

Compare & Sourcing

Compare side-by-side tradeoffs or verify active marker guidelines.

Review available sources for Guayusa

Independent database mapping — evaluated separately from safety and efficacy scores.

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Safety first · Harm reduction

This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.

Learn how we evaluate confidence, safety, and intensity on the methodology page.

Editorial Review

Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.

Editorial Standards →

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Botanical profile context

How to interpret Guayusa

Guayusa herb profile with evidence context, key research topics, source notes, safety context, and references presented in an evidence-first format. Use this herb profile as a starting point for evidence review, not as a recommendation to start a new supplement. Botanical products can vary by plant part, extract ratio, standardization, dose, and contaminant testing, so two labels with the same common name may not behave the same way.

When reviewing Guayusa, compare the traditional-use context against the human evidence, mechanism notes, and safety cautions. Pay special attention to pregnancy, breastfeeding, liver or kidney disease, blood-pressure effects, sedation, stimulation, anticoagulant use, antidepressants, and any prescription medication overlap.

For product decisions, prefer transparent labels, named extracts, clear serving sizes, and third-party quality testing. Avoid treating a long list of possible mechanisms as proof that an herb will solve a specific condition.