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Dietary supplement

Extra Strength Phosphatidyl Serine 300 mg Ingredients & Drug Interactions

by NOW

Extra Strength Phosphatidyl Serine 300 mg label
See full label image
Softgel Capsule Category: Fat/fatty Acid
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 Extra Strength Phosphatidyl Serine 300 mg 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

Extra Strength Phosphatidyl Serine 300 mg is a dietary supplement by NOW with 1 active ingredient. Its ingredients are commonly taken for memory and cognitive support, age-related cognitive decline, attention and focus (adhd).Based on those ingredients, 219 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Phosphatidyl Serine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Extra Strength Phosphatidyl Serine 300 mg by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Extra Strength Phosphatidyl Serine 300 mg by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Extra Strength Phosphatidyl Serine 300 mg by NOW

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

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This softgel contains one active ingredient: phosphatidylserine 300 mg per capsule. Phosphatidylserine is a naturally occurring compound found in cell membranes.

The softgel also holds inactive ingredients — MCT oil, sunflower lecithin, silica, and the capsule shell itself — that serve as the carrier and help deliver the active ingredient.

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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: memory, learning, mood and brain health.
  • We looked for evidence on: Age-related cognitive decline, Alzheimer disease, Cognitive function, Dementia, Depression, Attention deficit-hyperactivity disorder (ADHD) — and 2 related terms.
  • The strongest evidence on file: Phosphatidylserine is rated "Possibly Effective" for Age-related cognitive decline (Natural Medicines).
  • Also on file: Phosphatidylserine is rated "Possibly Effective" for Alzheimer disease.
  • Also on file: Phosphatidylserine is rated "Insufficient Reliable Evidence To Rate" for Attention deficit-hyperactivity disorder (ADHD), Cognitive function, Dementia, Depression.

Phosphatidylserine is possibly effective for age-related cognitive decline and Alzheimer disease based on the data we hold. For athletic performance, attention deficit-hyperactivity disorder (ADHD), general cognitive function, and dementia, the evidence available isn't reliable enough to rate whether it works.

If you're taking this for one of those latter uses, the science hasn't established it yet.

The evidence, ingredient by ingredient Phosphatidylserine

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.

Phosphatidylserine is generally well tolerated in studies, though long-term safety data is limited. The most common side effects are flatulence, gastrointestinal upset, headache, insomnia, and nausea — and gastrointestinal symptoms can occur even at the 300 mg dose in this product.

Insomnia is more likely at higher doses (600 mg), but headache has also been reported. There isn't enough safety information to know whether this supplement is safe during pregnancy, so avoidance is advised.

Safety while breastfeeding is also unknown, so it's best to avoid it then too. Talk with your doctor or pharmacist about your individual situation if you're pregnant, planning to become pregnant, or breastfeeding.

Side effects, ingredient by ingredient Phosphatidylserine

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 — Phosphatidylserine.
  • The most serious interaction on file is rated Moderate.
  • For scale: 219 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 this product, check with your doctor or pharmacist if you use anticholinergic drugs (such as medications for overactive bladder, certain motion sickness treatments, or some antihistamines) or cholinergic drugs (used for conditions like myasthenia gravis or Alzheimer disease) — both carry Moderate interaction risk with phosphatidylserine.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product may help with age-related cognitive decline or Alzheimer disease based on current evidence. However, if you take anticholinergic or cholinergic medications, check your exact drugs with your doctor or pharmacist before starting — the interaction risk is real.

It's not recommended during pregnancy or breastfeeding. Side effects like nausea and insomnia are possible, especially at higher doses.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Mar 24, 2017.

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 Extra Strength Phosphatidyl Serine 300 mg, straight from the product label.

Brand NOW
Barcode (UPC) 733739023926
Net contents 50 Softgel(s)
Market status On market
Date entered into DSLD Mar 24, 2017
DSLD ID 72424
Product type Fat/fatty Acid
Supplement form Softgel Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy 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 Extra Strength Phosphatidyl Serine 300 mg by NOW, 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 Softgel(s)
Maximum serving Sizes:
1 Softgel(s)
UPC/BARCODE
733739023926
IngredientAmount% DV
Calories10 Calorie(s)--
Total Fat1 Gram(s)1%
Phosphatidyl Serine300 mg--

Other ingredients: MCT Oil, Softgel Capsule, Sunflower Lecithin, 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.
Precautions

Keep out of reach of children.

Do not eat freshness packet. Keep in bottle.

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition.

Keep out of reach of children.

Not manufactured with yeast, wheat, gluten, corn, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

General Statements

Natural color variation may occur in this product.

Phosphatidyl Serine is a major structural component of neural membranes where it assists in the conduction of electrical impulses and facilitates the activity of neurotransmitters involved in learning, memory, and mood.*

Cognitive health*

~ Supports memory and brain function* ~ Promotes intercellular communication*

General Health

Family owned since 1968.

Formula

This extra strength product has three times the phosphatidyl serine (300 mg per softgel) than our regular strength product (100 mg per softgel).

Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 softgel daily with a meal.

Brand IP Statement(s)

NOW Phosphatidyl Serine is a phospholipid compound derived from soy lecithin that plays an essential role in cell membrane composition and intercellular communication.*

These properties make NOW Phosphatidyl Serine an ideal supplement for the support of cognitive function.

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.

General

CODE 2392 V1

FDA Statement of Identity

A Dietary Supplement

Formulation

Not manufactured with yeast, wheat, gluten, corn, milk, egg, fish, shellfish or tree nut ingredients.

Storage

Store in a cool, dry place after opening.

Seals/Symbols

GMP Quality Assured

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

See for yourself

Extra Strength Phosphatidyl Serine 300 mg by NOW label

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

Extra Strength Phosphatidyl Serine 300 mg 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 Extra Strength Phosphatidyl Serine 300 mg by NOW

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Softgel(s) Dosage formSoftgel Capsule Amounts shown are per serving.

Phosphatidyl Serine

Interacts with
219 drugs
300 mg per serving Form: Soy

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinki...

Phosphatidyl Serine monograph & interactions

Other (inactive) ingredients: MCT Oil, Softgel Capsule, Sunflower Lecithin, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Extra Strength Phosphatidyl Serine 300 mg by NOW Drug Interactions

Want to check YOUR meds against Extra Strength Phosphatidyl Serine 300 mg?

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
219Drugs
219 Moderate

Ingredients driving the most interactions

Phosphatidyl Serine 219

Individual Drug Interactions

The ingredients in Extra Strength Phosphatidyl Serine 300 mg interact with 219 drugs. Click any drug to see the details.

1 of the 1 ingredient in Extra Strength Phosphatidyl Serine 300 mg interact with drugs. Each result below shows which ingredient is responsible. Phosphatidyl Serine

Each ingredient & the kinds of drugs it affects

For each ingredient in Extra Strength Phosphatidyl Serine 300 mg 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.

Phosphatidyl Serine2 drug types · 219 drugs

Anticholinergic Drugs

Theoretically, phosphatidylserine might decrease the effectiveness anticholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically interfere with the activity of anticholinergic agents.

Likelihood Possible Evidence B
Cholinergic Drugs

Theoretically, phosphatidylserine might have additive effects with cholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically lead to additive cholinergic effects when used with cholinergic drugs.

Likelihood Possible Evidence B
Phosphatidyl Serine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Extra Strength Phosphatidyl Serine 300 mg, from the product label.

NOW

See all NOW products
Name
NOW Foods
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

Extra Strength Phosphatidyl Serine 300 mg by NOW: Common Questions

Does Extra Strength Phosphatidyl Serine 300 mg by NOW interact with any medications?
Yes. Based on its ingredients, Extra Strength Phosphatidyl Serine 300 mg has a known interaction with 219 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Extra Strength Phosphatidyl Serine 300 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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 if I'm pregnant or breastfeeding?
No — there isn't enough safety information. Avoidance is recommended during pregnancy and while breastfeeding. Talk with your doctor or pharmacist if you have questions about your specific situation.
What's the most common side effect?
Gastrointestinal upset — flatulence and nausea — can happen even at the 300 mg dose in this product. Headache and insomnia are also possible. Most people tolerate it well, but these effects have been reported in studies.
Does phosphatidylserine really help with memory or thinking?
It's possibly effective for age-related cognitive decline and Alzheimer disease based on available evidence. For general cognitive function, ADHD, and dementia, the science isn't clear enough to say whether it works.
What is phosphatidylserine?
It's a naturally occurring compound found in cell membranes throughout your body. Your body makes it, and you also get small amounts from foods, especially soy and meat products.
Are there any fillers in this softgel?
Besides the active ingredient, the capsule contains MCT oil, sunflower lecithin, and silica as inactive ingredients that help formulate and deliver the phosphatidylserine.

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

Not sure if Extra Strength Phosphatidyl Serine 300 mg 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.

Extra Strength Phosphatidyl Serine 300 mg label
Go deeper

The Full Monographs Behind Extra Strength Phosphatidyl Serine 300 mg’s Ingredients

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

Herb & supplement monograph

Phosphatidylserine

Interacts with 219 drugs

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinking. Some research suggests possible bene...

Read the full Phosphatidylserine monograph →
Sources

Sources & How We Checked

Extra Strength Phosphatidyl Serine 300 mg'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 9 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.

Phosphatidylserine 9 references
  1. Crook T, Petrie W, Wells C, Massari DC. Effects of phosphatidylserine in Alzheimer's disease. Psychopharmacol Bull 1992;28:61-6.
  2. Pepping J. Phosphatidylserine. Am J Health-Syst Pharm 1999;56:2038,2043-4.
  3. Kidd PM. Phosphatidylserine; Membrane nutrient for memory. A clinical and mechanistic assessment. Altern Med Rev 1996;1:70-84.
  4. Kim HY, Akbar M, Lau A, et al. Inhibition of neuronal apoptosis by docosahexaenoic acid (22:6n-3). Role of phosphatidylserine in antiapoptotic effect. J Biol Chem 2000;275:35215-23.. PubMed
  5. Zanotti A, Valzelli L, Toffano G. Chronic phosphatidylserine treatment improves spatial memory and passive avoidance in aged rats. Psychopharmacology (Berl) 1989;99:316-21.. PubMed
  6. Schreiber S, Kampf-Sherf O, Gorfine M, et al. An open trial of plant-source derived phosphatydilserine for treatment of age-related cognitive decline. Isr J Psychiatry Relat Sci 2000;37:302-7.
  7. Pepping, J. Phosphatidylserine. Am J Health Syst.Pharm. 10-15-1999;56(20):2038, 2043-2038, 2044.
  8. Monteverde, A., Gnemmi, P., Rossi, F., Monteverde, A., and Finali, G. C. Selegiline in the treatment of mild to moderate Alzheimer-type dementia. Clin.Ther 1990;12(4):315-322.
  9. Vakhapova V, Cohen T, Richter Y, Herzog Y, Kam Y, Korczyn AD. Phosphatidylserine containing omega-3 Fatty acids may improve memory abilities in nondemented elderly individuals with memory complaints: results from an open-label extension study. Dement Geri PubMed

See these in context on the Phosphatidylserine 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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