Drug & supplement interaction

Wild Indigo + Phenylephrine

Phenylephrine brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Wild Indigo and Phenylephrine 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

Wild Indigo and Phenylephrine

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 Phenylephrine and Wild Indigo 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 Wild Indigo at all — not against Phenylephrine, 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.

Wild Indigo safety at a glance

Wild Indigo overall Use caution It may be safe in small amounts short-term, but larger doses can be toxic and cause vomiting and other effects.
Pregnancy Likely Unsafe When used orally or topically due to its toxic potential. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally or topically due to its toxic potential. 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 Phenylephrine and Wild Indigo? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Wild Indigo and Phenylephrine 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.

  • Vomiting Additional detail

    Wild Indigo

    “Orally, large doses of wild indigo are considered poisonous and can cause vomiting, diarrhea, gastrointestinal complaints, and spasms (12). Wild indigo has also been studied in combination with other herbal extracts.”

    Wild Indigo · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.

    “Orally, large doses of wild indigo can cause vomiting, diarrhea, and gastrointestinal complaints (12).”

    Wild Indigo · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.

    Phenylephrine

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

Reported for Wild Indigo but not commonly for Phenylephrine: diarrhea.

Effects for Phenylephrine come from the ADVERSE REACTIONS section of its FDA label; effects for Wild Indigo come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 221,388 voluntary FDA FAERS reports for Phenylephrine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Wild Indigo in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally or topically due to its toxic potential.

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

Overlapping uses

What Phenylephrine Is Prescribed For, and What Wild Indigo Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Phenylephrine is a prescription medicine with approved uses on its FDA label. Wild Indigo is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Phenylephrine is prescribed for: Phenylephrine is used in several different products, and each one has its own use. Injection (IV): raises blood pressure in adults with clinically important hypotension (low blood pressure) caused mainly by widened blood vessels. Some injections are labeled for anesthesia only. Others are labeled for anesthesia and septic shock.

Read the rest of what Phenylephrine is prescribed for

Eye drops: Phenylephrine Hydrochloride Ophthalmic Solution is used to dilate the pupil. Nasal products: temporarily relieve nasal and sinus congestion from the common cold, hay fever or other upper respiratory allergies. Rectal suppositories: relieve itching, burning and discomfort from hemorrhoids and temporarily shrink hemorrhoidal tissue.

Wild Indigo has been studied for:

  • Common cold studied, not established Wild Indigo has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Wild Indigo for common cold

    Clinical research shows that taking three tablets of a specific combination product (Esberitox, Schaper & Brümmer GmbH & Co. KG) containing dry extracts of echinacea root, thuja leaf, and wild indigo root three times daily for 7-9 days improves the severity of cold symptoms, general well-being, and overall response rate when compared with placebo in patients experiencing moderate cold symptoms.

    1 source cited
    1. 6392. Henneicke-von Zepelin H, Hentschel C, Schnitker J, et al. Efficacy and safety of a fixed combination phytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of a randomised, double blind, placebo-controlled, m

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Phenylephrine on your own; if you are taking Wild Indigo for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Wild Indigo or Phenylephrine

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

This page covers Wild Indigo only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenylephrine page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Lithium (major), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 60 moderate · 15 minor.

From our pharmacist’s overview on the Phenylephrine page

“If you take phenylephrine (Sudafed PE, Biorphen) for congestion, treat this list as one that needs real attention, since six of its 81 entries carry a major rating. Phenylephrine tightens blood vessels to clear your nose, and more than half of the interactions here come from stimulant ingredients, ephedra above all, that can push blood…”

Reviewed by 2 · Jul 18, 2026

Open the Phenylephrine interaction page

One more smart check

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

We hold 175 real supplement products containing Wild Indigo, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wild Indigo. Even though Wild Indigo itself has no known interaction with Phenylephrine, 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 Wild Indigo and Phenylephrine 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 Wild Indigo
Top half

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

29 days ago today
Medication Phenylephrine
Top 25%

#507 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 Wild Indigo reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Wild Indigo and Phenylephrine 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 Wild Indigo

What is Wild Indigo?

  • Colds and flu
  • Immune support
  • Sore throat and upper respiratory infections
  • Minor infections
  • Mouth and gum irritation (traditional use)

Wild Indigo (Baptisia tinctoria) is a traditional herb most often used in combination products for colds and immune support, but high-quality human evidence is very limited. It can be toxic in larger amounts, so it should be used cautiously and only at low doses, and avoided in pregnancy and breastfeeding.

Baptisia tinctoria · Fabaceae · Root (and sometimes the leaves) · Tinctures, capsules, dried root for tea, and combination herbal products (often blended with echinacea and thuja)

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

Wild Indigo: dosing

There is no well-established standardized dose for wild indigo. It is most often found in small amounts within combination products, where the manufacturer sets the dose.Because the herb can be toxic at higher amounts, it is important to follow the product label exactly and not exceed the recommended dose. Do not assume that more is better.

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

Read the full Wild Indigo monograph & all interactions
Medication

About Phenylephrine

What Is Phenylephrine Used For?

Brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen

Phenylephrine is used in several different products, and each one has its own use.

Injection (IV): raises blood pressure in adults with clinically important hypotension (low blood pressure) caused mainly by widened blood vessels. Some injections are labeled for anesthesia only. Others are labeled for anesthesia and septic shock.

Eye drops: Phenylephrine Hydrochloride Ophthalmic Solution is used to dilate the pupil.

Nasal products: temporarily relieve nasal and sinus congestion from the common cold, hay fever or other upper respiratory allergies.

Rectal suppositories: relieve itching, burning and discomfort from hemorrhoids and temporarily shrink hemorrhoidal tissue.

Most-Reported Side Effects for Phenylephrine

From FAERS, the FDA’s public side-effect reporting system (221,388 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 20,609 reports
Headache 17,301 reports
Nausea 16,925 reports
Diarrhea 14,221 reports
Dyspnea 13,719 reports
See full Phenylephrine drug information
Keep checking

Other Drugs & Wild Indigo

Browse every other medication we’ve checked against Wild Indigo — 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 Wild Indigo 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 Wild Indigo list.

See the full Wild Indigo interactions page
See every supplement checked against Phenylephrine, ranked by severity
Evidence & sources

Wild Indigo References

The 3 references that drive our Wild Indigo 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Henneicke-von Zepelin H, Hentschel C, Schnitker J, et al. Efficacy and safety of a fixed combination phytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of a randomised, double blind, placebo-controlled, m

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 Wild Indigo and Phenylephrine Together: Common Questions

Is it safe to take Wild Indigo with Phenylephrine?
We do not list a known interaction between Wild Indigo and Phenylephrine. 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 Wild Indigo and Phenylephrine 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.
Are Wild Indigo and Phenylephrine used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Wild Indigo in each. That is a conversation for your prescriber, especially if Phenylephrine is being adjusted to a target.
Does Phenylephrine interact with any supplements?
Yes. Phenylephrine has documented interactions with 81 supplements in our database — Wild Indigo is not one of them. The Phenylephrine 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

Wild Indigo monograph Uses, safety profile, and every drug interaction in one place Phenylephrine drug information The full plain-English guide to this medication Phenylephrine supplement interactions Every supplement checked against Phenylephrine, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Phenylephrine and Wild Indigo?

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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.