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Dietary supplement

Four Ingredients & Drug Interactions

by Nature's Sunshine

Four label
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Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Four against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Four is a dietary supplement by Nature's Sunshine with 4 active ingredients. Its ingredients are commonly taken for sleep and insomnia, anxiety and stress, digestive upset.Based on those ingredients, 378 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Catnip, Mullein, Blessed Thistle. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Four by Nature's Sunshine

Ask about any prescription or over-the-counter medication and we check it for interactions with Four by Nature's Sunshine — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Four by Nature's Sunshine

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 30, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 4 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (740 mg) without saying how much of each component you get.

Four contains four active ingredients: catnip, blessed thistle, mullein, and yerba santa — each included in a proprietary blend. Catnip is traditionally used for digestive and nervous system support; blessed thistle has been used to support digestion and milk supply; mullein is a traditional respiratory herb; and yerba santa has been used in herbal practice for respiratory health.

The capsule itself is an inactive ingredient.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use.

Why this rating?
  • The label markets this product for: Traditional respiratory support.
  • We looked for evidence on: Asthma, Bronchitis, Common cold, Cough, Influenza, Upper respiratory tract infection (URTI) — and 3 related terms.
  • The closest evidence on file: Mullein is rated "Insufficient Reliable Evidence To Rate" for Bronchitis (Natural Medicines).
  • Also on file: Mullein is rated "Insufficient Reliable Evidence To Rate" for Asthma, Cough, Influenza.
  • Also on file: Catnip is rated "Insufficient Reliable Evidence To Rate" for Common cold, Influenza, Upper respiratory tract infection (URTI).

The evidence we hold on these ingredients is limited. Catnip, blessed thistle, mullein, and yerba santa all carry effectiveness ratings of insufficient reliable evidence for their traditional uses — meaning the data we have doesn't establish whether they work for amenorrhea, anxiety, tension headaches, common cold, digestive upset, cough, asthma, bronchitis, migraine, diarrhea, or weight loss.

That doesn't mean they don't work; it means rigorous studies haven't confirmed it yet.

The evidence, ingredient by ingredient Catnip Blessed Thistle Mullein Yerba Santa

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 3 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Catnip is generally well tolerated in tea amounts, though full safety data in humans are limited. Common side effects in appropriate doses are mild — headache, malaise, and vomiting — though large amounts may cause stomach upset.

Avoid catnip during pregnancy, as it may stimulate the uterus and safety hasn't been established. Blessed thistle is often well tolerated in small amounts but can cause stomach irritation and vomiting at high doses (more than 5 grams per cup of tea).

It's considered likely unsafe in pregnancy. In those breastfeeding, traditional use supports milk supply, but safety hasn't been well studied — check with your doctor first.

Mullein is generally well tolerated for short-term use; avoid it during pregnancy and while breastfeeding due to insufficient safety data. Yerba santa has limited human safety data and should be avoided in medicinal amounts during pregnancy and while nursing.

Side effects, ingredient by ingredient Catnip Blessed Thistle Mullein Yerba Santa

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 4 of the 4 matched ingredients can interact with medications — Blessed Thistle, Yerba Santa, Mullein, Catnip.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; lithium.
  • For scale: 378 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking Four, double-check with your doctor or pharmacist if you take lithium (a mood stabilizer), central nervous system depressants such as sedatives or anti-anxiety medications, blood thinners or antiplatelet drugs, or acid-reducing medications including H2-blockers, antacids, or proton pump inhibitors. The product's ingredients may interact with these drug types and affect how well they work or how high their levels climb in your body.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

This product combines four traditional herbal ingredients with limited human safety data and no established effectiveness for their claimed uses. If you take lithium, a sedative, blood thinners, or any acid-reducing medication for reflux or stomach ulcers, talk to your doctor or pharmacist before starting Four.

Even if you don't take any of these medications, it's worth checking your full prescription list with them first.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 22, 2020.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Four, straight from the product label.

Brand Nature's Sunshine
Barcode (UPC) 099904008922
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD May 22, 2020
DSLD ID 220498
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Kosher
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Four by Nature's Sunshine, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
50
UPC/BARCODE
099904008922
IngredientAmount% DV
Proprietary Blend740 mg--
Catnip0 NP--
Blessed Thistle0 NP--
Mullein0 NP--
Yerba Santa0 NP--

Other ingredients: Capsule

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Bottle made from 100% post consumer recycled material. We are committed to you and our planet. Scan to learn more.

We source the world's purest ingredients, no matter where they are grown, to ensure the active nutrients are delivered just as nature intended.

New look! Same great product

Herbal experts since 1972

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Seals/Symbols

Ko Kosher Service Pareve

Guaranteed Pure

Formula

Ko Kosher Service Pareve

Precautions

Do not use if inner seal is missing or damaged.

Formulation

Traditional respiratory support

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommended use: Take 2 capsules with a meal twice daily.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Four by Nature's Sunshine label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Four label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Four by Nature's Sunshine

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container50 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Blend

740 mg per serving

Other (inactive) ingredients: Capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

Four by Nature's Sunshine Drug Interactions

Want to check YOUR meds against Four?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
378Drugs
248 Moderate 130 Minor

Ingredients driving the most interactions

Catnip 248
Mullein 122
Blessed Thistle 36
Yerba Santa 1

Individual Drug Interactions

The ingredients in Four interact with 378 drugs. Click any drug to see the details.

4 of the 4 ingredients in Four interact with drugs. Each result below shows which ingredient is responsible. Catnip Mullein Blessed Thistle Yerba Santa

Each ingredient & the kinds of drugs it affects

For each ingredient in Four with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Catnip2 drug types · 248 drugs

Cns Depressants

Theoretically, concomitant use with drugs with sedative properties may cause additive effects and side effects.
Clinical and animal research shows that catnip has sedative properties.

Likelihood Possible Evidence D
Lithium

Theoretically, catnip might reduce excretion and increase levels of lithium.
Catnip is thought to have diuretic properties which might reduce lithium excretion. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Catnip full monograph & interactions

Mullein1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Lab tests on extracts from different parts of common and dense-flowered mullein plants show that they do have some blood-thinning effects, as they increase the time it takes for blood to clot. This is likely due to at least one of the known constituents of muellein, triterpenoid saponins. However, the effects appear to be mild and results have been inconsistent. Extracts from different plant parts have been show to have varying anticoagulant strengths, with water-based ones being more potent than alcohol-based extracts.

Likelihood Unlikely Evidence A
Mullein full monograph & interactions

Blessed Thistle3 drug types · 36 drugs

Antacids

Theoretically, blessed thistle might decrease the effectiveness of antacids.
There are reports that blessed thistle increases stomach acid.

Likelihood Possible Evidence D
H2-Blockers

Theoretically, blessed thistle might decrease the effectiveness of H2-blockers.
There are reports that blessed thistle increases stomach acid.

Likelihood Possible Evidence D
Proton Pump Inhibitors (Ppis)

Theoretically, blessed thistle might decrease the effectiveness of PPIs.
There are reports that blessed thistle increases stomach acid.

Likelihood Possible Evidence D
Blessed Thistle full monograph & interactions

Yerba Santa1 drug type · 1 drug

Lithium

Yerba santa is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, yerba santa might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Yerba Santa full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Four, from the product label.

Nature's Sunshine

See all Nature's Sunshine products
Name
Nature's Sunshine Products, Inc.
City
Spanish Fork
State
Utah
ZipCode
84660
Phone Number
1-800-223-8225
Web Address
www.naturessunshine.com
Pharmacist Counseling Corner

Four by Nature's Sunshine: Common Questions

Does Four by Nature's Sunshine interact with any medications?
Yes. Based on its ingredients, Four has a known interaction with 378 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Four contains 4 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take Four if I'm pregnant or breastfeeding?
The data advises against it. Catnip and blessed thistle are considered unsafe during pregnancy because they may stimulate the uterus and lack established safety. Mullein and yerba santa lack enough safety information for pregnancy — avoid medicinal amounts. For breastfeeding, blessed thistle is traditionally used to support milk supply but safety hasn't been well studied, so talk to your doctor first. Mullein and yerba santa haven't been studied in nursing mothers, so they're best avoided. There's no pregnancy or lactation data on file for catnip.
What are the most common side effects?
Catnip is generally well tolerated and the most common side effects — headache, malaise, and vomiting — occur with appropriate amounts. Large amounts may cause stomach upset. Blessed thistle can cause stomach irritation and vomiting at high doses. Mullein side effects from human use aren't well documented, though skin reactions have been reported from direct contact or inhalation of plant dust.
Does Four have fillers or just the active herbs?
The product contains the four active ingredients in a proprietary blend plus a capsule shell as an inactive ingredient.
Is there any evidence Four actually works?
The data we hold shows insufficient reliable evidence for all four ingredients — catnip, blessed thistle, mullein, and yerba santa — for any of their traditional uses. That means rigorous studies haven't confirmed their effectiveness yet, not that they don't work.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Four label
Go deeper

The Full Monographs Behind Four’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Catnip

Interacts with 248 drugs

Catnip is a mint-family herb most often used as a calming tea for sleep, anxiety, and minor digestive upset, but solid human research supporting these uses is lacking. It is generally consid...

Read the full Catnip monograph → Herb & supplement monograph

Blessed Thistle

Interacts with 36 drugs

Blessed thistle is a bitter herb traditionally used to stimulate appetite and ease mild digestive complaints. High-quality human studies are lacking, so its benefits are not well proven. It...

Read the full Blessed Thistle monograph → Herb & supplement monograph

Mullein

Interacts with 122 drugs

Mullein is a traditional herbal remedy most often used as a tea or syrup to soothe coughs, sore throats, and respiratory irritation. High-quality human studies are lacking, so its benefits a...

Read the full Mullein monograph → Herb & supplement monograph

Yerba Santa

Interacts with 1 drug

Yerba Santa is an aromatic shrub from the western United States and Mexico that has long been used in folk medicine for coughs, congestion, and other respiratory complaints. Modern scientifi...

Read the full Yerba Santa monograph →
Sources

Sources & How We Checked

Four's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 11 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Catnip 7 references
  1. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Osterhoudt KC, Lee SK, Callahan JM, Henretig FM. Catnip and the alteration of human consciousness. Vet Hum Toxicol 1997;39:373-5.
  5. Sherry, C. J. and Hunter, P. S. The effect of an ethanol extract of catnip (Nepeta cataria) on the behavior of the young chick. Experientia 2-15-1979;35(2):237-238. PubMed
  6. Harney, J. W., Barofsky, I. M., and Leary, J. D. Behavioral and toxicological studies of cyclopentanoid monoterpenes from Nepeta cataria. Lloydia. 1978;41(4):367-374.
  7. Massoco, C. O., Silva, M. R., Gorniak, S. L., Spinosa, M. S., and Bernardi, M. M. Behavioral effects of acute and long-term administration of catnip (Nepeta cataria) in mice. Vet.Hum.Toxicol 1995;37(6):530-533.

See these in context on the Catnip monograph →

Blessed Thistle 2 references
  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.

See these in context on the Blessed Thistle monograph →

Mullein 2 references
  1. Castro AI, Carmona JB, Gonzales FG, Nestar OB. Occupational airborne dermatitis from gordolobo (Verbascum densiflorum). Contact Dermatitis 2006;55(5):301.
  2. Flores Echaiz C, Al Ali A, Cao AQ, Sasseville D. Simultaneous contact dermatitis caused by Asteraceae and Verbascum thapsus. Contact Dermatitis 2017;76(5):316-8.

See these in context on the Mullein monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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