Quick summary

Boldo (Peumus boldus) is a medicinal plant traditionally used in various cultures. Ongoing research is investigating its potential benefits, particularly as a complementary treatment for urinary tract conditions like urolithiasis (kidney stones). It contains alkaloids such as boldine and has been studied for antioxidant properties. Clinical evidence on its efficacy and safety is still emerging, with some encouraging but limited human studies.

What is it

Boldo is a native South American shrub whose leaves have been used medicinally for centuries. The plant contains bioactive alkaloids, primarily boldine, which is thought to contribute to its pharmacological effects. Traditionally, the leaves are consumed as teas or extracts.

Traditional uses

  • Support of urinary tract health
  • Relief of digestive discomfort
  • Management of liver and gallbladder ailments (traditional claims)

Active compounds

The key active compound in boldo is boldine, an alkaloid with antioxidant properties. Other phytochemicals include flavonoids and essential oils. Boldine is the most researched molecule regarding biological activity.

Potential benefits with evidence levels

  • Distal ureteral stones (urolithiasis): Moderate clinical evidence from a 2024 retrospective cohort study suggests that boldine combined with Phyllanthus niruri, Ononis spinosa, and tamsulosin may increase stone expulsion rates, shorten expulsion time, reduce analgesic needs, and have comparable safety to tamsulosin alone.
    (Di Mauro E et al., 2024)
  • Oxalate nephrolithiasis (kidney stones): Preclinical and preliminary evidence from animal models indicates that boldo-containing herbal extracts may protect against kidney stone formation and associated renal inflammation.
    (Taheri H et al., 2024; Mutomba WF et al., 2025)
  • Diabetic retinopathy (oxidative stress reduction): In vitro studies on retinal explants from animal models show that boldine reduces oxidative-nitrosative stress under high glucose conditions, suggesting antioxidant potential.
    (Calbiague García V et al., 2023)
  • Asthma (potential therapeutic candidate): Bioinformatic predictions identified boldine as a potential drug for asthma treatment via molecular pathway analyses. Clinical evidence is lacking.
    (Nie X et al., 2019)
  • Antioxidant properties: Preclinical and bibliometric studies describe boldo as a contributor to Chilean antioxidant research, with boldine exhibiting free radical scavenging activity.
    (Lorca M et al., 2025)
  • Colorectal cancer (cytotoxic alkaloids): Boldine and related alkaloids showed moderate anti-cancer activity in in vitro cell line studies. Clinical relevance is not established.
    (Tabakam TG, Makhafola TJ, 2024)

Side effects

Adverse effects with boldo and related herbal products appear relatively infrequent but may include:

  • Headache
  • Dizziness
  • Nausea and vomiting
  • Postural hypotension (low blood pressure upon standing)
  • Backache
  • Allergic reactions (general concern with botanicals)
  • Rare potential hepatotoxicity reported in herbal-induced liver injury literature

Drug interactions

Direct evidence of boldo-specific drug interactions is limited. However, general herb-drug interaction literature suggests potential pharmacokinetic and pharmacodynamic interactions via enzyme modulation and effects on platelet/coagulation function. Caution is advised especially when used with anticoagulants (e.g., warfarin) and drugs with narrow therapeutic windows.

Anecdotal reports indicate possible interactions with immunosuppressants such as tacrolimus, but more clinical data are needed.

Who should avoid it

  • Individuals with known hypersensitivity to boldo or related compounds
  • People with liver disorders, given potential risk of hepatotoxicity associated with some botanicals
  • Pregnant or breastfeeding women, due to insufficient safety data

Evidence limitations

  • Most clinical evidence comes from small, single-center, retrospective cohort studies or preclinical models. High-quality randomized controlled trials are lacking.
  • Mechanisms of action, optimal dosing, and identification of specific patient populations who may benefit remain unclear.
  • Data on long-term safety, comprehensive drug interactions, and use in special populations (pregnant/nursing) are insufficient.
  • Many studies involve combination therapies, complicating isolation of boldo’s individual effects.

References

Last reviewed

June 2024

Disclaimer: This information is for educational purposes only and is not intended as medical advice. Always consult your healthcare provider before starting any new herbal treatment, especially if you have existing health conditions or are taking medications. The efficacy and safety of boldo have not been fully established, and more research is needed.