Drug & supplement interaction

Boldo + Fosamprenavir

Fosamprenavir brand names: Lexiva, Telzir.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Boldo and Fosamprenavir 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

Boldo and Fosamprenavir

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 Fosamprenavir and Boldo 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.

Boldo safety at a glance

Boldo overall Use caution May be used short-term in low doses, but the ascaridole in the leaf and oil can harm the liver.
Pregnancy Possibly Unsafe When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole constituent of... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole constituent of... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Fosamprenavir and Boldo? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Fosamprenavir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Fosamprenavir is filed under 4 classifications — including protease inhibitors (pis), cytochrome p450 3a4 (cyp3a4) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates. Boldo has documented interactions with 5 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), hepatotoxic drugs (moderate) and lithium (moderate) — and none of Fosamprenavir’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

Boldo Does Interact With Other Medications

Boldo has 482 moderate known drug interactions in our database — Fosamprenavir isn’t one of them. If you take anything else, check it against the full list below.

Moderate 482 No known interaction 2,348 (incl. Fosamprenavir)
Taking anything else?

Check Another of Your Medications Against Boldo

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

What to actually watch for

No Interaction Found — But Data Suggests Boldo and Fosamprenavir May Share Several of the Same Side Effects

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.

  • Stomach pain Additional detail

    Boldo

    “Orally, boldo is generally well tolerated when used in amounts commonly found in foods. However, when used in medicinal amounts, boldo can cause significant adverse effects such as hepatotoxicity. There is currently a limited amount of information on the adverse effects of topical boldo;”

    Boldo · Natural Medicines adverse-effect record, reported in dermatitis.

    Fosamprenavir

    Listed in the ADVERSE REACTIONS section of the FDA label for Fosamprenavir. Read the label on DailyMed ›

  • Tiredness Additional detail

    Boldo

    “Orally, boldo is thought to potentially cause hepatotoxicity. The volatile oil from the boldo leaf contains the liver toxin, ascaridole. In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo.”

    Boldo · Natural Medicines adverse-effect record, reported in alcohol-related liver disease.

    3 sources cited
    1. 13178. Piscaglia F, Leoni S, Venturi A, et al. Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity. Scand J Gastroenterol 2005;40:236-9. PubMed
    2. 100304. Ribeiro RJ, Silvestre C, Duarte C. Hidden risks of alternative medicines: a case of boldo-induced hepatotoxicity. J Diet Suppl 2017;14(2):186-90. PubMed
    3. 106431. Oliveira Sá A, Pimentel T, Oliveira N. Boldo-Induced Hepatotoxicity: A Case of Unexplained Jaundice. Eur J Case Rep Intern Med 2020;7(12):002116. PubMed

    Fosamprenavir

    Listed in the ADVERSE REACTIONS section of the FDA label for Fosamprenavir. Read the label on DailyMed ›

  • A skin rash Additional detail

    Boldo

    “Topically, boldo can be irritating when applied to the skin (4). In one case report, a healthy 64-year-old patient experienced allergic contact dermatitis in an airborne pattern on the face, arms, and dorsum of both hands following airborne exposure to boldo. After exposure to boldo was avoided, the dermatitis resolved.”

    Boldo · Natural Medicines adverse-effect record, reported in dermatitis.

    2 sources cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
    2. 106433. Valdes R, Feuereisen A, Bellinghausen M. Allergic Contact Dermatitis to Boldo. Dermatitis 2021;32(2):e31-e32. PubMed

    Fosamprenavir

    Listed in the ADVERSE REACTIONS section of the FDA label for Fosamprenavir. Read the label on DailyMed ›

  • Vomiting / Nausea Additional detail

    Boldo

    Recorded for Boldo in the same Natural Medicines adverse-effect record shown under Stomach pain above.

    Fosamprenavir

    Listed in the ADVERSE REACTIONS section of the FDA label for Fosamprenavir. Read the label on DailyMed ›

Reported for Boldo but not commonly for Fosamprenavir: an irregular heartbeat, stomach upset, liver problems and a fast or pounding heartbeat.

Effects for Fosamprenavir come from the ADVERSE REACTIONS section of its FDA label; effects for Boldo come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Boldo in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole constituent of boldo is a liver toxin.

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

Everything else you take

See Every Supplement That Interacts With Fosamprenavir

This page covers Boldo only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fosamprenavir page lists 143 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 · 100 moderate · 40 minor.

From our pharmacist’s overview on the Fosamprenavir page

“Fosamprenavir (Lexiva, Telzir) keeps HIV suppressed only if its blood level stays where it belongs, so the 143 supplement interactions on file deserve real attention, not a shrug. Three are rated major and those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Fosamprenavir interaction page

One more smart check

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

We hold 173 real supplement products containing Boldo, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Boldo. Even though Boldo itself has no known interaction with Fosamprenavir, 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 Boldo and Fosamprenavir 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 Boldo
Top half

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

29 days ago today
Medication Fosamprenavir
Steady interest

#2,027 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 Boldo reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Boldo and Fosamprenavir 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 Boldo

What is Boldo?

Boldo
  • Indigestion and bloating
  • Mild constipation
  • Liver and gallbladder support
  • Appetite stimulation
  • Urinary complaints

Boldo is a South American shrub whose leaves are traditionally used for digestive and gallbladder complaints, but good human evidence is very limited. The leaves and oil contain ascaridole, which can be toxic to the liver, so only ascaridole-free products should be used and only for short periods. Talk to your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Peumus boldus · Monimiaceae · Leaves and essential oil · Tea, dried leaf, tincture, capsules, essential oil

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

Boldo: dosing

There is no well-established standardized dose for boldo, and products vary widely in strength and in how much ascaridole they contain. Because of this, it is best to follow the directions on the product label and use it only for short periods.Choose products labeled as ascaridole-free when possible, and avoid the pure essential oil.

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

Read the full Boldo monograph & all interactions
Medication

About Fosamprenavir

What Is Fosamprenavir Used For?

Brand names: Lexiva, Telzir

Fosamprenavir tablets (sold as Fosamprenavir Calcium and Lexiva) are used together with other antiretroviral medicines to treat HIV-1 infection in adults and in children as young as 4 weeks old. It is not used alone — it is always part of a combination regimen.

For adults who have already taken protease inhibitor medicines before, fosamprenavir is used alongside a low dose of ritonavir. Once-daily dosing with ritonavir is not recommended for adults who have previously used protease inhibitors, or for any pediatric patients.

See full Fosamprenavir drug information
Keep checking

Other Drugs & Boldo

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

0Major
482Moderate
0Minor
2,347No known interaction
482 Moderate 2,347 No interaction
Moderate

482 interactions

Showing 60 of 482 moderate interactions — see all 482 on the Boldo page.

No interaction 2,347 drugs checked — show the list

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

Showing the 60 most looked-up of 2,347 medications checked with no known interaction — see the full Boldo list.

See the full Boldo interactions page
See every supplement checked against Fosamprenavir, ranked by severity
Evidence & sources

Boldo References

The 10 references that drive our Boldo 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. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Lambert J, Cormier J. Potential interaction between warfarin and boldo-fenugreek. Pharmacotherapy 2001;21:509-12. PubMed
  3. Piscaglia F, Leoni S, Venturi A, et al. Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity. Scand J Gastroenterol 2005;40:236-9. PubMed
  4. Agarwal SC, Crook JR, Pepper CB. Herbal remedies -- how safe are they? A case report of polymorphic ventricular tachycardia/ventricular fibrillation induced by herbal medication used for obesity. Int J Cardiol 2006;106:260-1. PubMed
  5. Teng, C. M., Hsueh, C. M., Chang, Y. L., Ko, F. N., Lee, S. S., and Liu, K. C. Antiplatelet effects of some aporphine and phenanthrene alkaloids in rabbits and man. J Pharm Pharmacol 1997;49(7):706-711. PubMed
  6. Carbajal R, Yisfalem A, Pradhan N, et al. Case report: Boldo (Peumus boldus) and tacrolimus interaction in a renal transplant patient. Transplant Proc 2014;46(7):2400-2. PubMed
  7. Almeida ER, Melo AM, Xavier H. Toxicological evaluation of the hydro-alcohol extract of the dry leaves of Peumus boldus and boldine in rats. Phytother Res 2000;14(2):99-102. DOI
  8. Ribeiro RJ, Silvestre C, Duarte C. Hidden risks of alternative medicines: a case of boldo-induced hepatotoxicity. J Diet Suppl 2017;14(2):186-90. PubMed
  9. Oliveira Sá A, Pimentel T, Oliveira N. Boldo-Induced Hepatotoxicity: A Case of Unexplained Jaundice. Eur J Case Rep Intern Med 2020;7(12):002116. PubMed
  10. Valdes R, Feuereisen A, Bellinghausen M. Allergic Contact Dermatitis to Boldo. Dermatitis 2021;32(2):e31-e32. PubMed

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 Boldo and Fosamprenavir Together: Common Questions

Is it safe to take Boldo with Fosamprenavir?
We do not list a known interaction between Boldo and Fosamprenavir. 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 Boldo and Fosamprenavir have any of the same side effects?
Yes — our sources link each of them separately to 5 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 Boldo and Fosamprenavir combination checked?
Interactions in our licensed database are recorded against drug classes. Fosamprenavir is filed under 4 classifications, and Boldo has documented interactions with 5 drug classes — none of Fosamprenavir'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 Boldo interact with any other medications?
Yes. Boldo has 482 documented drug interactions in our database — Fosamprenavir 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 Fosamprenavir interact with any supplements?
Yes. Fosamprenavir has documented interactions with 143 supplements in our database — Boldo is not one of them. The Fosamprenavir 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

Boldo monograph Uses, safety profile, and every drug interaction in one place Fosamprenavir drug information The full plain-English guide to this medication Fosamprenavir supplement interactions Every supplement checked against Fosamprenavir, 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Fosamprenavir and Boldo?

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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.