Drug & supplement interaction

Hartstongue + Famciclovir

Famciclovir brand name: Famvir.

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

We found no known interaction between Hartstongue and Famciclovir 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.

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Interaction report

Hartstongue and Famciclovir

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 Famciclovir and Hartstongue 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Hartstongue at all — not against Famciclovir, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Hartstongue safety at a glance

Hartstongue overall Not established Modern safety data are very limited, so caution is advised.
Pregnancy Avoid There is not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid it to be safe.

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

Still wondering about combining Famciclovir and Hartstongue? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Famciclovir’s Own FDA Label Lists

This is not an interaction — none of it involves Hartstongue. These are the most notable effects listed in the ADVERSE REACTIONS section of Famciclovir’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Hallucinations Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • Confusion Worth acting on
  • A severe skin reaction Worth acting on
  • Seizures Worth acting on
  • A low platelet count Worth acting on
  • Kidney problems Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on

Showing the 10 most notable of 28 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Famciclovir. Read the label on DailyMed › Where a percentage is shown, it is the share of 2,753 voluntary FDA FAERS reports for Famciclovir that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Hartstongue’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Hartstongue side to compare — that is a limit of the record, not a statement that Hartstongue has no side effects.

From our Q&A

Questions About Hartstongue or Famciclovir

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Hartstongue or Famciclovir, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Famciclovir

This page covers Hartstongue only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Famciclovir page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Famciclovir page

“Famciclovir (Famvir) treats herpes infections like shingles and cold sores, and it only works if enough of the drug gets absorbed from your gut, which is exactly where every supplement on this list can interfere. The entry I would take most seriously is activated charcoal, the lone major-rated interaction, because charcoal binds medica…”

Reviewed by 2 · Jul 18, 2026

Open the Famciclovir interaction page

One more smart check

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

We hold 2 real supplement products containing Hartstongue, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hartstongue. Even though Hartstongue itself has no known interaction with Famciclovir, 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 Hartstongue and Famciclovir 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 Hartstongue
Steady interest

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

29 days ago today
Medication Famciclovir
Top half

#1,384 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. Hartstongue is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Hartstongue reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Hartstongue and Famciclovir records this page draws on were last updated June 22, 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 Hartstongue

What is Hartstongue?

  • Cough and chest congestion
  • Digestive complaints
  • Liver and spleen support (traditional)
  • Mild diarrhea
  • Wound healing (topical, traditional)

Hartstongue is a fern that has been used in traditional European herbal medicine, mainly for coughs and digestive complaints. There is very little modern scientific research to confirm that it works for any health condition, so its effectiveness is largely unproven. If you are considering it, talk with a pharmacist or doctor first, and avoid it during pregnancy and breastfeeding.

Asplenium scolopendrium · Aspleniaceae · Leaves (fronds) · Dried herb, tea/infusion, tincture

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

Hartstongue: dosing

There is no established, scientifically supported dose for Hartstongue. Traditional use involved brewing the dried fronds as a tea, but standardized amounts have not been set through modern research.If you choose to use a commercial product, follow the directions on the label and do not exceed them.

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

Read the full Hartstongue monograph & all interactions
Medication

About Famciclovir

What Is Famciclovir Used For?

Brand name: Famvir

Famciclovir tablets are used in adults to treat recurrent cold sores (herpes labialis), recurrent episodes of genital herpes, and shingles (herpes zoster). For genital herpes, it can also be taken daily as suppressive therapy to reduce how often outbreaks happen.

In adults living with HIV, famciclovir is used to treat recurrent episodes of orolabial herpes (cold sores) or genital herpes. It is not approved for a first-ever genital herpes outbreak, herpes affecting the eye (ophthalmic zoster), or for use in children.

Most-Reported Side Effects for Famciclovir

From FAERS, the FDA’s public side-effect reporting system (2,753 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 191 reports
Diarrhea 183 reports
Nausea 153 reports
Headache 142 reports
Rash 114 reports
See full Famciclovir drug information
Keep checking

Other Drugs & Hartstongue

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Hartstongue list.

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

Hartstongue References

The 2 sources that drive our Hartstongue monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Hartstongue is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Herbs at a Glance — NIH NCCIH Source
  2. Herbs and Supplements — MedlinePlus Source

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 Hartstongue and Famciclovir Together: Common Questions

Is it safe to take Hartstongue with Famciclovir?
We do not list a known interaction between Hartstongue and Famciclovir. 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.
Does Famciclovir interact with any supplements?
Yes. Famciclovir has documented interactions with 17 supplements in our database — Hartstongue is not one of them. The Famciclovir 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

Hartstongue monograph Uses, safety profile, and every drug interaction in one place Famciclovir drug information The full plain-English guide to this medication Famciclovir supplement interactions Every supplement checked against Famciclovir, 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 Famciclovir and Hartstongue?

Our pharmacists answer your medication & supplement questions — free.

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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.