No known drug interactions for the matched ingredients — not a guarantee none exist. Check your meds →
Dietary supplement

L-Ornithine 500 mg Ingredients & Drug Interactions

by NOW

Capsule Category: Amino Acid/protein
No known interaction
The interaction bottom line No known interaction

L-Ornithine 500 mg is a dietary supplement by NOW with 1 active ingredient. Its ingredients are commonly taken for athletic performance and recovery, reducing fatigue, sleep and stress support.We don’t currently list a known drug interaction for its mapped ingredients — but that doesn’t guarantee none exist, so always confirm with your pharmacist.

HelloPharmacist Scorecard of L-Ornithine 500 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

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 product contains one active ingredient: L-ornithine, an amino acid (a building block your body uses to make proteins). The capsule also holds inactive ingredients — hypromellose, microcrystalline cellulose, and stearic acid — which are standard fillers and binders that help hold the supplement together.

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: amino acid for protein metabolism and athletic performance.
  • We looked for evidence on: Athletic performance, Wound healing, Ammonia metabolism, Muscle recovery.
  • The strongest evidence on file: Ornithine is rated "Possibly Effective" for Athletic performance (Natural Medicines).
  • Also on file: Ornithine is rated "Insufficient Reliable Evidence To Rate" for Wound healing.

L-ornithine is possibly effective for athletic performance. For other uses listed — dry skin, insomnia, and periodontitis (gum inflammation) — the evidence we hold is insufficient to rate whether it works.

That doesn't mean it won't help, just that we don't have solid trial data backing those claims yet.

The evidence, ingredient by ingredient Ornithine

How safe is it?

Some data gaps
Safety Information · database check
Some gaps

Safety data exists for these ingredients, but with some important gaps.

Why this rating?
  • We hold adverse-effect (side-effect) data for 0 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.

L-ornithine is generally well tolerated in the short term, but long-term safety hasn't been well studied, so we don't have a lot of data on what happens if you take it for months or years. The safety data advises against use during pregnancy and while breastfeeding due to insufficient information — talk with your doctor or pharmacist about your individual situation if you're pregnant, planning to become pregnant, or nursing.

Side effects, ingredient by ingredient Ornithine

Meds to double-check

No known interactions
Known Interaction Concern · database check
No known interactions

No medication interactions are currently documented for the matched ingredients — that isn't a guarantee none exist.

Why this rating?
  • None of the 1 matched ingredient has a documented medication interaction on file.

No interactions are documented in our data for the ingredients we checked. Still, run your specific medications through the search tool on this page, and ask your doctor or pharmacist to review your full list before you start.

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. No medication interactions are currently documented, and some safety-information gaps remain.

L-ornithine may be worth considering if you're interested in supporting athletic performance, though the evidence is modest. If you're pregnant, breastfeeding, or taking any medications, check with your doctor or pharmacist first.

Long-term use hasn't been well studied, so it's best suited to short-term use.

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 Jun 20, 2024.

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 L-Ornithine 500 mg, straight from the product label.

Brand NOW
Barcode (UPC) 733739001221
Net contents 120 Veg Capsule(s)
Market status On market
Date entered into DSLD Jun 20, 2024
DSLD ID 314452
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, 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 L-Ornithine 500 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:
3 Veg Capsule(s)
Maximum serving Sizes:
3 Veg Capsule(s)
Servings per container
40
UPC/BARCODE
733739001221
IngredientAmount% DV
L-Ornithine1500 mg--

Other ingredients: Hypromellose, Microcrystalline Cellulose, Stearic Acid

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.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 3 capsules daily with juice or water on an empty stomach.

Formula

Ornithine is a non-essential amino acid that plays a central role in the urea cycle, functioning along with arginine and citrulline to rid the body of ammonia, a by-product of protein metabolism. Because ornithine is converted into Arginine, it can help to maintain healthy Arginine levels in the body. Ornithine can also be converted into other amino acids, such as citrulline, proline, and glutamate, as well as creatine, an important muscular energy source.

Triangle K (Kosher)

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

GMP Quality Assured

Triangle K (Kosher)

Formulation

Fitness amino acid Healthy protein metabolism

Non-GMO

Vegetarian/Vegan

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

Made and quality in the USA with globally sourced ingredients. Natural color variation may occur in this product.

FDA Statement of Identity

A Dietary Supplement

General Statements

Amino acids Family owned since 1968.

Precautions

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

Caution: For adults only.

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

Keep out of reach of children.

Storage

Store in a cool, dry place after opening.

See for yourself

L-Ornithine 500 mg by NOW label

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

What’s inside

The Ingredients in L-Ornithine 500 mg by NOW

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

Serving size3 Veg Capsule(s) Dosage formCapsule Servings per container40 Amounts shown are per serving.

L-Ornithine

No known
interactions
1500 mg per serving Form: L-Ornithine Hydrochloride

Ornithine is a non-essential amino acid your body makes naturally as part of the urea cycle, which helps remove ammonia. It is sold as a supplement fo...

L-Ornithine monograph & interactions

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

Interaction report

L-Ornithine 500 mg by NOW Drug Interactions

We don’t currently list any known drug interactions for the mapped ingredients in L-Ornithine 500 mg. This doesn’t guarantee none exist — always confirm with your pharmacist before combining a supplement with your medications.

The maker

Brand information

Manufacturer and brand details for L-Ornithine 500 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

L-Ornithine 500 mg by NOW: Common Questions

Does L-Ornithine 500 mg by NOW interact with any medications?
We do not currently list a known interaction for the mapped ingredients in L-Ornithine 500 mg. This does not guarantee none exist, so confirm with your pharmacist.
How can one product interact with so many drugs?
L-Ornithine 500 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 L-ornithine if I'm pregnant?
The safety data we hold advises against it — there isn't enough information to know it's safe during pregnancy. Talk with your doctor or pharmacist about your individual situation before taking it.
Is L-ornithine safe to take long-term?
It's generally well tolerated in the short term, but long-term safety hasn't been well studied. Your doctor or pharmacist can help you decide whether longer use is right for you.
Does L-ornithine really help with athletic performance?
The evidence suggests it's possibly effective for athletic performance, but the data isn't rock-solid. Results can vary from person to person.
Can I take L-ornithine if I'm breastfeeding?
The safety data advises against it due to insufficient information. Talk with your doctor or pharmacist about what's safe for you and your baby.
What is L-ornithine?
It's an amino acid — one of the building blocks your body uses to make proteins. Your body produces some on its own, and you can also get it from foods and supplements.

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

Not sure if L-Ornithine 500 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

L-Ornithine 500 mg label
Go deeper

The Full Monographs Behind L-Ornithine 500 mg’s Ingredients

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

Sources

Sources & How We Checked

L-Ornithine 500 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 1 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.

Ornithine 1 reference
  1. Dietary Supplements: What You Need to Know — NIH Office of Dietary Supplements Source

See these in context on the Ornithine 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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