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 your body makes naturally. The capsule also holds inactive ingredients (cellulose, rice flour, and magnesium stearate) that help hold it together and make it easier to swallow.

Does it work?

Couldn't assess
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 assessable

We hold no graded evidence for this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: ammonia metabolism and protein byproduct removal.
  • We looked for evidence on: urea cycle function, nitrogen metabolism.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

L-ornithine appears possibly effective for athletic performance based on the evidence we have. For dry skin, insomnia, and periodontitis (gum disease), the evidence isn't strong enough to say whether it works — the data rates these uses as having insufficient reliable evidence.

You'd be using this product in an area where proof is still limited.

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 know how it holds up over months or years. The safety data advises against use during pregnancy and while breastfeeding because there isn't enough evidence to know it's safe in those situations.

Talk with your doctor or pharmacist before using it 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 for L-ornithine in our data.

The bottom line

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

L-ornithine might appeal to you if you're looking to support athletic performance, since there's some evidence for that. Just know the data on other uses is thin, and we don't have long-term safety information.

If you're pregnant, breastfeeding, or on medications, check in with your doctor or pharmacist before starting.

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 Nov 24, 2015.

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) 733739001207
Net contents 60 Veg Capsule(s)
Market status On market
Date entered into DSLD Nov 24, 2015
DSLD ID 53383
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, 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 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
20
UPC/BARCODE
733739001207
IngredientAmount% DV
L-Ornithine1.5 Gram(s)--

Other ingredients: Cellulose, Rice Flour, Magnesium Stearate

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.

General Statements

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 byproduct 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.*

CAPSULE SIZE

Fitness Amino Acid*

Healthy Protein Metabolism*

Amino Acids

Family owned since 1968.

Natural color variation may occur in this product.

Please Recycle.

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.

Precautions

Caution: For adults only.

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

Keep out of reach of children.

Do Not Eat Freshness Packet. Keep in Bottle.

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

FDA Statement of Identity

A Dietary Supplement

Formulation

Vegetarian/Vegan

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

Seals/Symbols

Non-GMO

GMP QUALITY ASSURED

Storage

Store in a cool, dry place after opening.

General

CODE 0120B V4

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 container20 Amounts shown are per serving.

L-Ornithine

No known
interactions
1.5 Gram(s) 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: Cellulose, Rice Flour, Magnesium Stearate. 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.
Does L-ornithine actually help with workouts or athletic performance?
The evidence rates it as possibly effective for athletic performance, which means there's some support for it but it's not a slam-dunk. Your results may vary, and it's not a substitute for training and good nutrition.
Can I take this if I'm pregnant or breastfeeding?
The safety data advises against it — there isn't enough information to know it's safe during pregnancy or while nursing. Talk with your doctor or pharmacist about whether it's right for you in those situations.
Will L-ornithine help my insomnia or dry skin?
We don't have enough reliable evidence to say whether it works for either of those. The data on both is rated insufficient, so you'd essentially be experimenting.
Is this safe to take long-term?
Short-term use appears generally well tolerated, but the long-term safety hasn't been well studied. If you're thinking about taking it regularly for months, that's a conversation to have with your pharmacist or doctor.

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

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

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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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