No known drug interactions for the matched ingredients — not a guarantee none exist. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

L-Ornithine 667 mg Ingredients & Drug Interactions

by Source Naturals

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

L-Ornithine 667 mg is a dietary supplement by Source Naturals with 2 active ingredients. 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 667 mg by Source Naturals

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, at 667 mg per capsule. The capsule itself is made from gelatin, with silica and magnesium stearate added as inactive ingredients to help with manufacturing and consistency.

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 energy and muscle support.
  • We looked for evidence on: Athletic performance, Wound healing, muscle recovery, fatigue reduction.
  • 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 dry skin, insomnia, and periodontitis (gum disease), the evidence we hold is insufficient to rate whether it works.

That means the research isn't settled yet — you may see claims out there, but we don't have reliable data backing those uses.

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, though long-term safety hasn't been well studied. The safety data advises against use during pregnancy and while breastfeeding — there isn't enough information to know it's safe in those situations.

Talk with your doctor or pharmacist if you're pregnant, planning to become pregnant, or nursing before starting this supplement.

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 said, always confirm with your own doctor or pharmacist before adding any new supplement to your medications.

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.

If you're an athlete looking at L-ornithine for performance, it's worth a conversation with your doctor or pharmacist first — especially if you take any regular medications or have kidney or liver concerns. Anyone pregnant or breastfeeding should avoid it until they've checked with their healthcare provider.

No documented interactions appear in our data, but that's not a blanket green light to mix with every drug.

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, 2023.

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 667 mg, straight from the product label.

Brand Source Naturals
Barcode (UPC) 021078016427
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2023
DSLD ID 295949
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, 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 L-Ornithine 667 mg by Source Naturals, 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:
3 Capsule(s)
Servings per container
33
UPC/BARCODE
021078016427
IngredientAmount% DV
Calories10 Calorie(s)--
Protein2 Gram(s)4%
L-Ornithine2 Gram(s)--

Other ingredients: Gelatin, Silica, 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.
FDA Statement of Identity

Amino Acid Supplement

Formulation

Free-Form

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat.

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.

Formula

L-Ornithine, a free-form crystalline amino acid is a precursor of arginine, which is necessary for the synthesis of creatine, an important energy provider for muscles. In addition, L-ornithine is a key compound in the urea cycle, one of the body's main processes for eliminating ammonia.

Suggested/Recommended/Usage/Directions

Suggested Use: 1 to 3 capsules 1 to 2 times daily. Use before exercise or at bedtime with plenty of water.

Precautions

Note: If you are pregnant, may become pregnant, or breastfeeding, consult your health care professional before using this product.

Do not use if either tamper-evident seal is broken or missing.

Keep out of the reach of children.

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.

Brand IP Statement(s)

Copyright Source Naturals, Inc

See for yourself

L-Ornithine 667 mg by Source Naturals label

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

What’s inside

The Ingredients in L-Ornithine 667 mg by Source Naturals

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container33 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.

Protein

2 Gram(s) per serving

L-Ornithine

No known
interactions
2 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: Gelatin, Silica, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Ornithine 667 mg by Source Naturals Drug Interactions

We don’t currently list any known drug interactions for the mapped ingredients in L-Ornithine 667 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 667 mg, from the product label.

Source Naturals

Name
Source Naturals, Inc.
Street Address
P. O. Box 2118
City
Santa Cruz
State
CA
ZipCode
95062
Web Address
www.sourcenaturals.com
Pharmacist Counseling Corner

L-Ornithine 667 mg by Source Naturals: Common Questions

Does L-Ornithine 667 mg by Source Naturals interact with any medications?
We do not currently list a known interaction for the mapped ingredients in L-Ornithine 667 mg. This does not guarantee none exist, so confirm with your pharmacist.
How can one product interact with so many drugs?
L-Ornithine 667 mg 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.
What is L-ornithine and what does it do?
L-ornithine is an amino acid — one of the building blocks your body uses to make proteins. This product is possibly effective for athletic performance, though we don't yet have reliable evidence for uses like dry skin, insomnia, or gum disease.
Is L-ornithine safe to take while I'm pregnant or breastfeeding?
The safety data advises against use during pregnancy and while breastfeeding because there isn't enough information to know it's safe. Talk with your doctor or pharmacist before taking it if you're pregnant, planning to become pregnant, or nursing.
Are there any side effects I should know about?
We don't have adverse effects documented in our data for L-ornithine. It's generally well tolerated in the short term, though long-term safety hasn't been well studied.
How long can I safely take L-ornithine?
L-ornithine is generally well tolerated in the short term, but long-term safety is not well studied. If you're planning to take it regularly, check with your doctor or pharmacist for personalized guidance.
Does it interact with medications?
No interactions are documented in our data for L-ornithine. That doesn't guarantee none exist — use the interaction checker on this page with your specific medications, and confirm with your doctor or pharmacist before starting.

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

Not sure if L-Ornithine 667 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 667 mg label
Go deeper

The Full Monographs Behind L-Ornithine 667 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 667 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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