Many oral care products use “aroma” or artificial flavour systems — proprietary blends designed primarily for taste and sensory impact.

We take a different approach.

At Truthpaste, our flavours aren't just flavours, they're functional.

Our citrus flavour comes from sweet orange and lemon essential oils, selected not only for their clean, fresh profiles, but also for oral health benefits.

Because every ingredient in our formulas has to earn its place.

Citrus in Toothpaste: More Than Just Flavour

When people hear “citrus” and “teeth” in the same sentence, they think one thing:

Acid.

But citrus essential oil in toothpaste is not the same thing as drinking orange juice.

And when formulated correctly, citrus isn’t just safe — it can actually contribute to oral health in several ways.

Let’s break it down simply.

1. Citrus Oil Is Not Citrus Juice

First, the important distinction.

Orange juice is acidic because it contains citric acid dissolved in water.

Sweet orange essential oil is completely different.

It’s extracted from the peel and contains aromatic compounds — primarily limonene — not citric acid.

When used in small, controlled amounts in a balanced toothpaste formula, it does not make the product acidic.

Flavour does not equal pH.

2. Citrus Contains Limonene — A Biologically Active Compound

Sweet orange and lemon oils are rich in limonene. 

Limonene has been studied for several properties relevant to oral health:

• Antimicrobial activity against certain bacteria

• Anti-inflammatory potential

• Ability to interact with lipid layers and biofilms 

It’s not just fragrance — it’s biologically active.

3. Supporting the Surface Environment of the Tooth

A 2020 in-vitro study (Ma et al.) examined limonene on demineralised dentin surfaces.

Researchers observed that limonene:

• Modestly increased calcium and phosphate presence on demineralised surfaces

• Helped protect dentin collagen from breakdown
  

a 2025 study (Chopra et al.) found that a lemon essential oil toothpaste showed remineralisation performance comparable to a calcium/phosphate toothpaste (measured by surface microhardness).

This suggests citrus essential oil dentifrices can play a supportive role in enamel/dentin repair systems — though human clinical trials are still needed

It’s important to note that these studies were conducted in a laboratory setting, and limonene is not a primary remineralising agent.

However, dentin collagen acts as a structural scaffold beneath enamel. Preserving that framework helps maintain surface integrity and may support mineral attachment.

In our formulation, hydroxyapatite provides the mineral.
Citrus contributes supportive activity around that process.

4. Mild Antimicrobial Activity

Oral health isn’t about killing everything.

It’s about balance.

Limonene has shown antimicrobial activity in laboratory studies against certain bacteria and fungi. It may help disrupt biofilm formation and interfere with bacterial adhesion.

This doesn’t mean it replaces brushing.
And it doesn’t mean it sterilises the mouth.

But it may contribute to a cleaner surface environment.

5. Biofilm Interaction

Oral health depends on managing biofilm (plaque) — the structured community of bacteria that forms on tooth surfaces.

Laboratory studies suggest limonene can:

• Interact with lipid components of bacterial membranes

• Disrupt biofilm formation in certain strains

This does not replace brushing.
But it may contribute to a healthier surface environment when combined with mechanical cleaning.

6. Potential Anti-Inflammatory Support

Inflammation is central to gum discomfort and periodontal issues.

Limonene has demonstrated anti-inflammatory effects in various biological models. While oral-specific clinical trials are limited, the mechanism suggests it may contribute to overall gum comfort when incorporated into a well-balanced formulation.

7. Behavioural Benefits

There is also a practical consideration.

Long-term enamel support depends on consistent brushing and repeated exposure to remineralising ingredients.

If flavour improves brushing experience, it supports compliance. 

Consistency is one of the most underrated drivers of oral health outcomes.

The Role of Citrus in our Remineralising Formula 

Citrus does not replace remineralising minerals.

In our toothpaste:

• Hydroxyapatite supplies calcium and phosphate to support enamel surface repair.

• Citrus oils provides limonene — contributing mild antimicrobial, collagen-supportive, and anti-inflammatory properties.

It’s a complementary relationship.

At Truthpaste, flavour is never an afterthought.

If an ingredient is included, it must contribute — either structurally, biologically, or behaviourally.

Citrus does all three.

Sources

Ma, Y., et al. (2020). Effects of lemon essential oil and limonene on the progress of dentin early caries. Archives of Oral Biology, 115, 104744.

Chopra, V., Pathak, R., Samir, P.V., Gupta, K., Mahesh, D.R. and Rao, V. (2025). Evaluating the Remineralizing Potential of Dentifrices Containing Lemon Essential Oil. Journal of Pharmacy and Bioallied Sciences

Burt, S. (2004). Essential oils: their antibacterial properties and potential applications. International Journal of Food Microbiology, 94(3), pp.223–253.