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Dietary supplement

Immune Shield H Formula Natural Immune Stimulator Ingredients & Drug Interactions

by Douglas Laboratories

Immune Shield H Formula Natural Immune Stimulator label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Immune Shield H Formula Natural Immune Stimulator 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

Immune Shield H Formula Natural Immune Stimulator is a dietary supplement by Douglas Laboratories with 2 active ingredients. Its ingredients are commonly taken for cold sores (herpes labialis), genital herpes outbreaks, supporting protein and collagen formation.Based on those ingredients, 265 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Lysine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories

Ask about any prescription or over-the-counter medication and we check it for interactions with Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories

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 Aug 6, 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 1 of its 3 active ingredients.
  • “L-Lysine” is listed as a grouped ingredient — the label gives one combined amount (250 mg) without saying how much of each component you get.
  • “Proprietary Base” is a proprietary blend — the label gives one combined amount (125 mg) without saying how much of each component you get.

This formula has three active ingredients. Melissa officinalis (lemon balm) is an herbal extract traditionally used for immune support and stress.

L-Lysine is an amino acid, and Nat-Stim is listed without detail in the available product information. The capsules also contain cellulose and silica as inactive ingredients.

Does it work?

Moderate evidence
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

This product doesn't appear to be marketed for a specific use, so we graded Lemon Balm's overall clinical evidence instead.

Moderate

Some clinical evidence supports Lemon Balm for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Herpes labialis (cold sores) — rated "Possibly Effective" (Natural Medicines).
  • On file: Depression — rated "Possibly Effective" (Natural Medicines).
  • On file: Stress — rated "Possibly Effective" (Natural Medicines).

Lemon balm is rated possibly effective for cold sores and possibly effective for stress and depression based on the evidence we have. The effectiveness of L-Lysine and Nat-Stim for immune support is not established in our data.

The evidence, ingredient by ingredient Lysine

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 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Lemon balm is generally well tolerated for short-term use in healthy adults, though long-term safety hasn't been well studied. Side effects like dizziness and sedation have been reported, but they don't appear more common with lemon balm than placebo in clinical trials.

One case of a serious heart rhythm issue was reported with a product containing lemon balm and other ingredients, but it's unclear whether lemon balm alone caused it — the person recovered after stopping the product. During pregnancy, safety data is insufficient, so lemon balm is best avoided unless your doctor advises otherwise.

While breastfeeding, limited safety information exists — talk with your doctor or pharmacist before use.

Side effects, ingredient by ingredient Lysine

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?
  • 1 of the 1 matched ingredient can interact with medications — Lemon Balm.
  • The most serious interaction on file is rated Moderate.
  • For scale: 264 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.

Check before taking if you use thyroid hormone replacement therapy — lemon balm may interfere with how it works. Also double-check if you take CNS depressants (sedating medications, sleep aids, anti-anxiety drugs, or certain painkillers), as lemon balm may add to their drowsiness.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

If you take thyroid medication or CNS depressants (sedating drugs), you'll want to check this with your doctor or pharmacist before starting. Lemon balm appears possibly effective for cold sores and stress, though it's not studied long-term.

Pregnant people should avoid it unless their doctor says otherwise.

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

Assessment coverage: 1 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 1, 2012.

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 Immune Shield H Formula Natural Immune Stimulator, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539012512
Net contents 30 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Jun 1, 2012
DSLD ID 9867
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Dairy Free, Sugar Free
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 Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories, 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:
1 Vegetarian Capsule(s)
Maximum serving Sizes:
2 Vegetarian Capsule(s)
Servings per container
30
UPC/BARCODE
310539012512
IngredientAmount% DV
L-Lysine250 mg--
Nat-Stim25 mg--
Proprietary Base125 mg--
Melissa officinalis0 NP--
Red Marine Algae0 NP--

Other ingredients: Cellulose, Silica

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.
Formulation

This product contains NO yeast, wheat gluten, soy protein, milk/dairy, corn, sodium, sugar, starch, artificial coloring, preservatives or flavoring.

FDA Statement of Identity

A Dietary Supplement

Precautions

Tamper resistant package, do not use if outer seal is missing.

KEEP OUT OF REACH OF CHILDREN.

General

Formula #80440

Storage

For optimal storage conditions, store in a cool, dry place. (59(0)-77(0)F/15(0)-25(0)C) (35-65% relative humidity)

Suggested/Recommended/Usage/Directions

Suggested Usage: Adults take 1-2 capsules daily or as directed by physician.

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

See for yourself

Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories label

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

Immune Shield H Formula Natural Immune Stimulator 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 Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Vegetarian Capsule(s) Dosage formCapsule Servings per container30 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.

L-Lysine

Interacts with
1 drug
250 mg per serving

Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to t...

L-Lysine monograph & interactions
  • › Proprietary Base

Nat-Stim

25 mg per serving Form: L-Mannose, Lactobacillus bulgaricus, lipopolysaccharide, Mannitol, murein, N-Acetyl-D-Glucosamine, n-acetylmuramic acid, Peptidoglycan

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

Interaction report

Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Immune Shield H Formula Natural Immune Stimulator?

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
265Drugs
264 Moderate 1 Minor

Ingredients driving the most interactions

L-Lysine 1

Individual Drug Interactions

The ingredients in Immune Shield H Formula Natural Immune Stimulator interact with 265 drugs. Click any drug to see the details.

1 of the 2 ingredients in Immune Shield H Formula Natural Immune Stimulator interact with drugs. Each result below shows which ingredient is responsible. L-Lysine

Each ingredient & the kinds of drugs it affects

For each ingredient in Immune Shield H Formula Natural Immune Stimulator with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

L-Lysine1 drug type · 1 drug

5-Ht4 Agonists

Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Animal research suggests that L-lysine is a partial serotonin receptor 4 (5-HT4) antagonist and inhibits diarrhea induced by the 5-HT4 agonist, 5-hydroxytryptophane.

Likelihood Unlikely Evidence D
L-Lysine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Immune Shield H Formula Natural Immune Stimulator, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
City
Pittsburgh
State
PA
ZipCode
15205
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories: Common Questions

Does Immune Shield H Formula Natural Immune Stimulator by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Immune Shield H Formula Natural Immune Stimulator has a known interaction with 265 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Immune Shield H Formula Natural Immune Stimulator contains 2 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 this while pregnant?
Safety data for lemon balm in pregnancy is insufficient, so it's best avoided unless your doctor advises otherwise. Talk with your doctor or pharmacist about whether it's right for you.
Can I take this while breastfeeding?
Limited safety information exists for lemon balm during breastfeeding. Use caution and talk to your doctor before using it while nursing.
Does lemon balm really help with cold sores?
Lemon balm is rated possibly effective for cold sores based on available evidence, though it's not proven conclusively.
Will this make me drowsy?
Lemon balm has been reported to cause dizziness and sedation in some cases, though clinical trials show it doesn't occur more often than placebo. If you're sensitive to sedating effects, start cautiously and watch how you feel.
What is L-Lysine and what does it do?
L-Lysine is an amino acid. We don't have effectiveness data on file for its role in this immune formula.
What's in the 'Proprietary Base'?
The proprietary base is listed as a blend container, but its individual component ingredients aren't detailed in the product information we have.

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

Not sure if Immune Shield H Formula Natural Immune Stimulator is safe with your meds?

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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.

Immune Shield H Formula Natural Immune Stimulator label
Go deeper

The Full Monographs Behind Immune Shield H Formula Natural Immune Stimulator’s Ingredients

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

Herb & supplement monograph

Lysine

Interacts with 1 drug

Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to try to prevent or shorten cold sores, but...

Read the full Lysine monograph →
Sources

Sources & How We Checked

Immune Shield H Formula Natural Immune Stimulator'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 19 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.

Lysine 7 references
  1. Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol 1984;58:659-66. PubMed
  2. McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
  3. DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
  4. Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol 1980;60:85-7.
  5. Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica 1987;175:183-90. DOI
  6. Lo JC, Chertow GM, Rennke H, Seifter JL. Fanconi's syndrome and tubulointerstitial nephritis in association with L-lysine ingestion. Am J Kidney Dis 1996;28:614-7. PubMed
  7. Smriga M, Torii K. L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15370-5.

See these in context on the Lysine monograph →

Lemon Balm 12 references
  1. Wolbling RH, Leonhardt K. Local therapy of herpes simplex with dried extract from Melissa officinalis. Phytomedicine 1994;1:25-31.
  2. Akhondzadeh S, Noroozian M, Mohammadi M, et al. Melissa officinalis extract in the treatment of patients with mild to moderate Alzheimer's disease: a double blind, randomised, placebo controlled trial. J Neurol Neurosurg Psychiatry 2003;74:863-6. PubMed
  3. Kennedy DO, Scholey AB, Tildesley NT, et al. Modulation of mood and cognitive performance following acute administration of Melissa officinalis (lemon balm). Pharmacol Biochem Behav 2002;72:953-64. PubMed
  4. Albrecht M, Berger W, Laux P, Schmidt U, et al. Psychopharmaka und Verkehrssicherheit. Der Einfluß von Euvegal® - Dragees forte auf die Fahrtüchtigkeit und Kombinationswirkungen mit Alkohol Z Allg Med 1995;71:1215-25.
  5. Herberg, KW. Nebenwirkungen pflanzlicher Beruhigungsmittel/ Leistung und Befinden nach Einnahme einer Baldrian-Hopfen-Kombination. Z.Allg Med 1996;72:234-240.
  6. Soulimani R, Fleurentin J, Mortier F, et al. Neurotropic action of the hydroalcoholic extract of Melissa officinalis in the mouse. Planta Med. 1991 Apr;57:105-9.
  7. Sourgens H, Winterhoff H, Gumbinger HG, et al. Antihormonal effects of plant extracts. TSH- and prolactin-suppressing properties of Lithospermum officinale and other plants. Planta Med. 1982 Jun;45:78-86. DOI
  8. Auf'mkolk M, Ingbar JC, Amir SM, et al. Inhibition by certain plant extracts of the binding and adenylate cyclase stimulatory effect of bovine thyrotropin in human thyroid membranes. Endocrinology. 1984 Aug;115:527-34. PubMed
  9. Santini F, Vitti P, Ceccarini G, et al. In vitro assay of thyroid disruptors affecting TSH-stimulated adenylate cyclase activity. J Endocrinol Invest. 2003 Oct;26:950-5. PubMed
  10. Alijaniha F, et al. Heart palpitation relief with Melissa officinalis leaf extract: double blind, randomized, placebo controlled trial of efficacy and safety. J Ethnopharmacol. 2015;164:378-384. doi: 10.1016/j.jep.2015.02.007. Epub 2015 Feb 11. PubMed
  11. Araj-Khodaei M, Noorbala AA, Yarani R, et al. A double-blind, randomized pilot study for comparison of Melissa officinalis L. and Lavandula angustifolia Mill. with Fluoxetine for the treatment of depression. BMC Complement Med Ther. 2020;20(1):207. PubMed
  12. Kucuk U, Pham M, Raza Raja MH, Saad Shaukat MH, Clark R. Transient complete atrioventricular block associated with herbal supplement use. S D Med 2023;76(7):311-313.

See these in context on the Lemon Balm 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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