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 Douglas Laboratories

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

L-Ornithine 500 mg is a dietary supplement by Douglas Laboratories 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 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

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 Hydrochloride, an amino acid. The capsule also holds inactive ingredients — gelatin, microcrystalline cellulose, magnesium silicate, and vegetable stearate — which are the capsule shell and fillers that help hold everything 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

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

Moderate

Some clinical evidence supports Ornithine 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: Athletic performance — rated "Possibly Effective" (Natural Medicines).

L-Ornithine is rated possibly effective for athletic performance. For dry skin, insomnia, and periodontitis (gum inflammation), the evidence we have isn't strong enough yet to say one way or the other — the data is insufficient.

If you're thinking about L-Ornithine for one of those conditions, talk it over with your doctor or pharmacist to see if it makes sense for you.

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 over the short term, but we don't have much data on long-term use, so that's something to keep in mind. During pregnancy, there isn't enough safety information — the data advises against it.

The same goes for breastfeeding. If you're pregnant, planning to become pregnant, or breastfeeding, talk with your doctor or pharmacist before taking L-Ornithine.

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 L-Ornithine. That doesn't mean none exist, so if you're on any medications, especially those that affect your liver or kidneys, it's worth confirming with your doctor or pharmacist before you begin.

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. No medication interactions are currently documented, and some safety-information gaps remain.

L-Ornithine may be worth considering if you're looking for a supplement to support athletic performance. The safety data is solid for short-term use, but we don't know much about taking it long-term.

If you're pregnant, breastfeeding, or on any medications, check with your own doctor or pharmacist before you start.

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 Aug 23, 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 L-Ornithine 500 mg, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539006412
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232442
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
310539006412
IngredientAmount% DV
L-Ornithine Hydrochloride500 mg--

Other ingredients: Gelatin, Microcrystalline Cellulose, Magnesium Silicate, Vegetable 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: As a dietary supplement, adults take 1 capsule daily or as directed by your health professional.

Precautions

Warning: If you are pregnant, nursing, have any health condition or taking any medication, consult your health professional before using this product.

Keep out of the reach of children.

Use only if safety seal is intact.

Storage

Store in a cool, dry place.

Formulation

Gluten-free, Non-GMO

FDA Disclaimer Statement

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

General Statements

Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.

FDA Statement of Identity

Dietary Supplement

See for yourself

L-Ornithine 500 mg by Douglas Laboratories 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 Douglas Laboratories

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

L-Ornithine Hydrochloride

No known
interactions
500 mg per serving

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 Hydrochloride monograph & interactions

Other (inactive) ingredients: Gelatin, Microcrystalline Cellulose, Magnesium Silicate, Vegetable Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Ornithine 500 mg by Douglas Laboratories 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.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Phone Number
1.800.245.4440
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

L-Ornithine 500 mg by Douglas Laboratories: Common Questions

Does L-Ornithine 500 mg by Douglas Laboratories 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 while I'm pregnant?
No — there isn't enough safety data during pregnancy, and the available information advises against it. Talk with your doctor or pharmacist about what's right for you.
Is it safe while breastfeeding?
There isn't enough safety data while breastfeeding either, so it's best to avoid it. Check with your doctor or pharmacist for personalized advice.
Does L-Ornithine actually help with athletic performance?
The evidence says it's possibly effective for athletic performance — so there's some support, but the data isn't overwhelming. Whether it'll help you is an individual question worth discussing with your doctor.
Is it safe to take long-term?
We have good safety data for short-term use, but long-term safety hasn't been well studied. If you're thinking about taking it for months on end, bring that up with your doctor or pharmacist.
What does L-Ornithine do in the body?
L-Ornithine is an amino acid — a building block your body uses to make protein and support various functions. It's been studied mainly for athletic performance and a few other conditions, but the strongest evidence is for workouts.

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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