# Nitric Oxide Supplements: What You Need to Know

Published: 2026-03-17

Nitric Oxide Supplements: What You Need to Know | GetMatter Heart Health

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# Nitric Oxide Supplements: What You Need to Know

A practical guide to understanding how these supplements work, what to look for, and how to use them safely.

8 min read
•
[NK
Medically reviewed by Dr. Nouman Kazmi, MBBS FCPS](https://getmatter.co/pages/matter-cardiologist-dr-syed-nouman-kazmi "View reviewer profile")

## Key takeaways

* Nitric oxide supplements don't contain NO directly — they provide precursors that your body converts into NO
* Two main pathways produce NO: dietary nitrates (beetroot, leafy greens) and amino acids (L-citrulline)
* Look for products with beetroot extract and L-citrulline combined for comprehensive support
* Avoid antiseptic mouthwash for 30 minutes after nitrate-rich foods — it can disrupt the conversion process
* Allow 6–8 weeks of consistent use before expecting noticeable changes
* Consult your GP if you're on blood pressure medication or nitrates (GTN) before starting supplements

## What are nitric oxide supplements, really?

Here's the most important thing to understand straight away: nitric oxide supplements don't actually contain nitric oxide. Instead, they contain precursors — compounds your body converts into NO through natural biological pathways.

This distinction matters because it shapes how you use them and what results you can reasonably expect. Your body is doing the heavy lifting, not the pill.

### The two production pathways

Your body makes nitric oxide through two main routes:

**1. The Dietary Nitrate Pathway** is the most common. Nitrates from foods like beetroot, spinach, rocket, and kale travel to your mouth, where oral bacteria convert them into nitrite. This nitrite is swallowed, reaches your stomach, and converts into NO. This is a surprisingly elegant system — your oral microbiome is critical to the process working at all.

**2. The Amino Acid Pathway** works differently. L-citrulline (an amino acid found in foods and supplements) converts to L-arginine in your kidneys and tissues. L-arginine then triggers an enzyme called eNOS (endothelial nitric oxide synthase) to produce NO directly. This pathway is less dependent on your oral bacteria, making it a useful complement to the dietary nitrate route.

How the Two Nitric Oxide Pathways Work

#### Dietary Nitrate Pathway

🥬

Beetroot & Leafy Greens

↓

B

Oral Bacteria Convert to Nitrite

↓

N

Nitrite Becomes Nitric Oxide

Blood Vessels Relax

#### Amino Acid Pathway

C

L-Citrulline Consumed

↓

A

Converts to L-Arginine

↓

E

eNOS Enzyme Produces NO

Improved Circulation

## A Nobel Prize-winning discovery

In 1998, three scientists — Robert Furchgott, Louis Ignarro, and Ferid Murad — won the Nobel Prize in Physiology or Medicine for discovering nitric oxide as a biological signalling molecule. This was landmark research: it was the first time a gas had been identified as playing such a fundamental role in the body.

Their work transformed how we understand circulation and cardiovascular health. Yet many people managing their circulation have never heard the story. Understanding the science behind NO can help you use supplements more intelligently.

~50%

**Decline in nitric oxide production by age 40**. This gradual reduction in NO is associated with changes in how blood vessels function and their flexibility — one reason why circulation support becomes increasingly relevant with age.

## What to look for in a supplement

Not all NO-support products are created equal. Here's what matters when you're evaluating options:

### Beetroot extract with measurable nitrate content

The most evidence-backed approach involves dietary nitrates. Look for products that specify beetroot extract concentration or actual nitrate content (typically 200–500 mg per serving). Whole beetroot powder is less concentrated than extract. If the label doesn't mention either, it's likely underdosed.

### L-citrulline over L-arginine

If the supplement uses amino acids, L-citrulline is more bioavailable than L-arginine. L-arginine is rapidly metabolised in the stomach and intestines, while L-citrulline has better absorption and longer circulation time. Most modern NO-support supplements use citrulline for this reason.

### Supporting cofactors matter

Nitric oxide production benefits from antioxidant support. Look for ingredients like vitamin C or polyphenols, which help protect NO from being broken down too quickly. These cofactors don't make NO directly, but they create better conditions for it to do its job.

### Multi-pathway formulas are more comprehensive

Single-ingredient products (beetroot only, or L-citrulline only) are effective, but combining both pathways is more thorough. This addresses NO production through different mechanisms, making your approach more robust.

## The mouthwash warning you should know

This is a practical detail that trips people up: antiseptic mouthwash kills the oral bacteria responsible for converting nitrates to nitrite. If you rinse vigorously with antiseptic mouthwash immediately after consuming nitrate-rich foods or supplements, you're essentially stopping the process mid-conversion.

If you use nitric oxide-supporting supplements, avoid antiseptic mouthwash for 30 minutes beforehand — or better yet, just skip it that day. This isn't a reason to abandon oral hygiene; it's just about timing. Regular toothbrushing is fine and doesn't interfere.

Pro Tip

If you enjoy beetroot juice or leafy green smoothies as part of your NO-support approach, swish your mouth with plain water after consuming them, then wait 20–30 minutes before using any antiseptic rinse. This preserves the conversion window.

## Safety: When to check with your GP

Nitric oxide supplements are generally well-tolerated by most people. However, they're not for everyone, and certain medications create potential interactions.

### Speak to your GP if you're taking:

* **Blood pressure medication** — Particularly ACE inhibitors or ARBs. NO has blood pressure-regulating properties, and combining it with medication requires medical oversight.
* **Nitrate medications (GTN, isosorbide, etc.)** — Often prescribed for angina. Adding a NO-support supplement on top of nitrate medication could potentiate the effect, which needs professional evaluation.
* **Phosphodiesterase-5 inhibitors** — Medications like sildenafil. These interact with NO metabolism and shouldn't be combined with supplements without medical guidance.

If you're not on any of these medications, NO-support supplements are generally safe. However, a quick check-in with your practice is always sensible before starting something new.

**Important:** Do not start or stop any supplement without consulting your healthcare provider if you have cardiovascular disease, take blood pressure medication, or are on nitrate therapy. Nitric oxide affects blood pressure regulation, and interactions are possible.

## Why consistency matters — the 6 to 8 week timeline

One of the biggest mistakes people make with NO-support supplements is expecting immediate results. They take a supplement for a week or two, feel no difference, and stop.

Here's the reality: just as nitric oxide production declines gradually over years, restoring it takes time. Research suggests that 6–8 weeks of consistent daily use is when most people notice meaningful trends in how they feel — better energy, improved circulation sensation, or reduced fatigue during exertion.

This isn't because the supplement is slow to work; it's because your endothelial function (the health of your blood vessel lining) is gradually improving. That's a real, structural change, not a quick fix.

## A multi-pathway approach for best results

While single-ingredient NO-support products work, combining pathways gives you the most comprehensive approach. This might look like:

* A supplement containing both beetroot extract and L-citrulline (hitting both pathways)
* Regular aerobic exercise (which naturally boosts NO production)
* Consuming nitrate-rich foods like rocket, spinach, and cooked beetroot on most days
* Avoiding antiseptic mouthwash around your nitrate intake
* Good sleep and stress management (both support endothelial health)

Supplements alone aren't the answer — they're one part of a broader strategy to support your circulation.

---

## Supporting your circulation with Heart Beets by GetMatter

If you're ready to take a structured approach to nitric oxide support, [understanding NO basics](https://getmatter.co/blogs/heart-health/nitric-oxide-explained-a-simple-guide-to-circulation-and-vascular-health) is the first step. Our Heart Beets formula combines both pathways — organic beetroot extract (high in nitrates) plus L-citrulline — to support your body's natural NO production.

For more on how NO functions in your cardiovascular system, see [What Does Nitric Oxide Do for You?](https://getmatter.co/blogs/heart-health/what-does-nitric-oxide-do) And if you're curious about circulation broadly, explore [signs of poor circulation](https://getmatter.co/blogs/heart-health/signs-of-poor-circulation) and [the best drink for blood circulation](https://getmatter.co/blogs/heart-health/best-drink-for-blood-circulation).

Science-Backed Support

## Ready to support your circulation?

Heart Beets by GetMatter combines beetroot extract and L-citrulline to support your body's natural nitric oxide production. Two pathways. One formula.

[Heart Beets by GetMatter](https://getmatter.co/products/blood-flow)

[Related article

What Does Nitric Oxide Do for You?](https://getmatter.co/blogs/heart-health/what-does-nitric-oxide-do)
[Related article

Nitric Oxide Explained: A Simple Guide to Circulation and Vascular Health](https://getmatter.co/blogs/heart-health/nitric-oxide-explained-a-simple-guide-to-circulation-and-vascular-health)

**Medically reviewed by [Dr. Syed Nouman Kazmi, MBBS FCPS](https://getmatter.co/pages/matter-cardiologist-dr-syed-nouman-kazmi)**Consultant Cardiologist · PMDC Verified · PSIC Certified
Dr. Kazmi reviews GetMatter health content for clinical accuracy. [View full profile →](https://getmatter.co/pages/matter-cardiologist-dr-syed-nouman-kazmi)

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Source: https://getmatter.co/blogs/heart-health/nitric-oxide-supplements-what-you-need-to-know