Drug & supplement interaction

Herb Robert + Liothyronine

Liothyronine brand name: Cytomel.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Herb Robert and Liothyronine 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

Herb Robert and Liothyronine

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 Liothyronine and Herb Robert 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 Herb Robert at all — not against Liothyronine, 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.

Herb Robert safety at a glance

Herb Robert overall Use caution Generally used in small amounts traditionally, but human safety data are very limited.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid No reliable safety data exist for nursing mothers, so avoid use.

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

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

No Interaction Found — But Data Suggests Herb Robert and Liothyronine May Share a Side Effect

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.

  • A skin rash Additional detail

    Herb Robert

    “There is currently a limited amount of information on the adverse effects of Herb Robert. Topically, Herb Robert has been reported to cause allergic contact dermatitis.”

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

    2 sources cited
    1. 99144. Svendsen MT, Andersen KE, Thormann H, Paulsen E. Contact sensitization to Geranium robertianum L. in an amateur gardener. Contact Dermatitis. 2015;72(6):420-1.
    2. 99146. Badaoui A, Pecquet C, Fargeas C, Mahé E. Contact dermatitis caused by Geranium robertianum with erythema multiforme-like reaction. Contact Dermatitis. 2017;77(6):423-424.

    “Topically, Herb Robert can cause contact dermatitis. There are at least two cases of known contact sensitization of elderly individuals to Herb Robert through gardening. One case resulted in an erythema multiforme-like eruption requiring treatment with steroids.”

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

    2 sources cited
    1. 99144. Svendsen MT, Andersen KE, Thormann H, Paulsen E. Contact sensitization to Geranium robertianum L. in an amateur gardener. Contact Dermatitis. 2015;72(6):420-1.
    2. 99146. Badaoui A, Pecquet C, Fargeas C, Mahé E. Contact dermatitis caused by Geranium robertianum with erythema multiforme-like reaction. Contact Dermatitis. 2017;77(6):423-424.

    Liothyronine

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

Reported for Herb Robert but not commonly for Liothyronine: a severe skin reaction.

Effects for Liothyronine come from the ADVERSE REACTIONS section of its FDA label; effects for Herb Robert 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.

From our Q&A

Questions About Herb Robert or Liothyronine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Herb Robert or Liothyronine, 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 Liothyronine

This page covers Herb Robert only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Liothyronine page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 26 moderate · 10 minor.

From our pharmacist’s overview on the Liothyronine page

“Liothyronine (Cytomel) is the active thyroid hormone T3, and it does not tolerate interference well. Of the 38 supplements and herbs on file, 21 act on thyroid function itself, some amplifying the hormone and others blunting it, iodine-rich seaweeds able to swing either way.”

Reviewed by 2 · Jul 18, 2026

Open the Liothyronine interaction page

How much people look this up

Where Herb Robert and Liothyronine 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 Herb Robert
Steady interest

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

29 days ago today
Medication Liothyronine
Top half

#924 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 Herb Robert reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Herb Robert and Liothyronine 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 Herb Robert

What is Herb Robert?

Herb Robert
  • Digestive upset
  • Wound and skin care
  • Sore throat and mouth irritation
  • Respiratory complaints
  • General 'detox' tonic

Herb Robert is a traditional European herb used for digestion, wounds, and minor inflammation, but there is very little human research to confirm it works for any condition. It is likely fine in small amounts as a tea for most healthy adults, but its safety has not been well studied. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Geranium robertianum · Geraniaceae · Above-ground parts (leaves, stems, and flowers) · Tea, tincture, dried herb, capsules, fresh poultice

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

Herb Robert: dosing

There is no established, standardized dose for Herb Robert. Traditional use involved brewing a small amount of the dried herb as a tea or applying crushed fresh leaves to the skin, but these amounts were not measured in a consistent, science-based way.If you choose to use a commercial product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Herb Robert monograph & all interactions
Medication

About Liothyronine

What Is Liothyronine Used For?

Brand name: Cytomel

Liothyronine (available as tablets under the brand names Cytomel, Liomny, and Liothyronine Sodium, and as an injection under Liothyronine Sodium and Triostat) is primarily used to treat hypothyroidism (an underactive thyroid) across all its forms — whether the cause is in the thyroid itself, the pituitary gland, or the hypothalamus, and whether it was present at birth or developed over time.

The oral tablets are also used alongside surgery and radioiodine therapy to suppress TSH (thyroid-stimulating hormone) in people with well-differentiated thyroid cancer, and as a diagnostic agent in thyroid suppression tests. Liothyronine sodium injection is specifically indicated for myxedema coma (a life-threatening form of severe hypothyroidism) and may be used in patients who are allergic to thyroid products derived from pork or beef.

Most-Reported Side Effects for Liothyronine

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Headache 885 reports
Fatigue 849 reports
Nausea 585 reports
Dyspnea 559 reports
Hypertension 467 reports
See full Liothyronine drug information
Keep checking

Other Drugs & Herb Robert

Browse every other medication we’ve checked against Herb Robert — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Herb Robert References

The 3 references that drive our Herb Robert 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. Svendsen MT, Andersen KE, Thormann H, Paulsen E. Contact sensitization to Geranium robertianum L. in an amateur gardener. Contact Dermatitis. 2015;72(6):420-1.
  2. Panahi Y, Akhavan A, Sahebkar A, et al. Investigation of the effectiveness of Syzygium aromaticum, Lavandula angustifolia and Geranium robertianum essential oils in the treatment of acute external otitis: a comparative trial with ciprofloxacin. J Microbi PubMed
  3. Badaoui A, Pecquet C, Fargeas C, Mahé E. Contact dermatitis caused by Geranium robertianum with erythema multiforme-like reaction. Contact Dermatitis. 2017;77(6):423-424.

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 Herb Robert and Liothyronine Together: Common Questions

Is it safe to take Herb Robert with Liothyronine?
We do not list a known interaction between Herb Robert and Liothyronine. 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 Herb Robert and Liothyronine have any of the same side effects?
Yes — our sources link each of them separately to one 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.
Does Liothyronine interact with any supplements?
Yes. Liothyronine has documented interactions with 38 supplements in our database — Herb Robert is not one of them. The Liothyronine interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Liothyronine and Herb Robert?

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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.