Can a Serum Be 97% Natural-Origin and Still Contain a Synthetic Peptide?
At 28N, natural-origin percentages are calculated against ISO 16128 — and the remaining few percent are chosen with intention, not hidden.
Natural-origin claims in skincare can sound simple.
In reality, they are often misunderstood.
At 28N Skincare, our A⁶ Anti-Ageing Formula is calculated at 97.43% natural origin. Our B⁶ Brightening Formula is calculated at 96.48% natural origin.
Both percentages are calculated against ISO 16128, the international framework used to define and calculate natural and natural-origin cosmetic ingredients and finished products.
But here is the part that matters:
A formula can be over 97% natural origin and still contain a carefully chosen synthetic ingredient.
That does not make the formula less honest.
It makes the calculation more important.
“Natural” Is Not Always as Simple as It Sounds
In beauty, the word “natural” is used often.
Sometimes it means plant-based. Sometimes it means naturally derived. Sometimes it means a formula contains a few botanical ingredients. And sometimes, it is used more as a feeling than a measurable standard.
That is why we prefer to be specific.
When we say A⁶ Anti-Ageing Formula is 97.43% natural origin, or B⁶ Brightening Formula is 96.48% natural origin, we are not using a vague marketing description.
We are referring to a calculation.
ISO 16128 provides a framework for classifying cosmetic ingredients as natural, natural-derived, organic, organic-derived, or synthetic, and for calculating the natural-origin content of a finished cosmetic formula.
It is not about making the formula sound cleaner.
It is about showing the method behind the number.
How Natural-Origin Percentage Is Calculated
The number on a formula is not based on how many ingredients sound natural.
It is based on weight.
Each ingredient in a formula is assigned a Natural Origin Index. This index reflects how much of that ingredient is considered natural or natural-derived under the ISO 16128 framework.
Then, that index is multiplied by how much of the total formula that ingredient represents by weight.
The contributions are added together.
That final number becomes the natural-origin percentage of the finished product.
So, if an ingredient is 100% natural origin and makes up a large part of the formula, it contributes strongly to the final percentage.
If an ingredient is synthetic and used at a very low level, it only reduces the final percentage by that same small amount.
This is the part that is often missed:
Natural-origin percentage is a weighted calculation, not a popularity vote between ingredients.
A formula can contain one or two synthetic ingredients and still be very high in natural-origin content if the majority of the formula, by weight, comes from natural or natural-derived sources.
Why A⁶ Is 97.43% Natural Origin — And Still Contains a Synthetic Peptide
A⁶ Anti-Ageing Formula contains Amplified Argireline®, a peptide used to help improve the appearance of expression lines.
Amplified Argireline® is not a botanical extract.
It is a lab-synthesised peptide.
And we are comfortable saying that clearly.
Why?
Because for this particular function, the synthetic option offers a level of precision and consistency that cannot simply be replaced by a plant extract.
Peptides are built from amino acids in a specific sequence. In the case of Amplified Argireline®, that sequence is designed for targeted cosmetic performance in the appearance of expression lines.
Under ISO 16128-style thinking, this type of ingredient does not become “natural” simply because amino acids exist in nature. The final peptide is assembled through a controlled synthesis process. For natural-origin calculation purposes, it is treated as synthetic.
That means it does not receive natural-origin credit in our calculation.
We could have used softer language.
We could have made it sound more natural.
But that would miss the point.
A⁶ is 97.43% natural origin because the full formula, by weight, is overwhelmingly made from natural or natural-derived ingredients.
The remaining portion includes selected synthetic ingredients we chose for a reason.
Not by accident.
Not for marketing.
For performance.
Synthetic Does Not Automatically Mean Bad
One of the biggest misconceptions in skincare is that “natural” means safe and “synthetic” means harsh.
Skin does not read marketing categories that way.
A natural essential oil can be irritating for some people.
A synthetic peptide can be well tolerated and highly targeted.
What matters is not whether an ingredient sounds natural.
What matters is:
- what it is designed to do
- how it is used
- at what concentration
- how it fits into the full formula
- whether the claim is supported by evidence
That is the way we formulate.
Natural-origin where it makes sense.
Synthetic where the data makes a stronger case.
Always with transparency.
Where Natural Ingredients Do Make Sense: Bakuchiol
A⁶ Anti-Ageing Formula also contains bakuchiol, one of the best-known plant-based alternatives to retinol.
This is an example where the natural option has a strong evidence story.
Bakuchiol is extracted from the seeds of Psoralea corylifolia. It is not a retinoid, and it does not have the same chemical structure as retinol, but research has shown that it can support visible improvements in photoageing concerns.
In a 2019 prospective, randomized, double-blind study published in the British Journal of Dermatology, bakuchiol 0.5% cream used twice daily was compared with retinol 0.5% cream used once daily over 12 weeks.
Both groups showed significant improvements in wrinkle surface area and hyperpigmentation, with no statistically significant difference between bakuchiol and retinol for those measured outcomes.
The retinol group, however, reported more facial scaling and stinging.
That is the kind of natural-alternative story we can support.
Not because “plant-based” sounds better.
Because the research gives the ingredient a real reason to be there.
CycloRetin™: A Natural Active With a Different Retinol-Alternative Story
A⁶ also contains CycloRetin™, a natural active derived from Prince ginseng.
CycloRetin™ is based on heterophyllin B, a cyclic peptide found in Pseudostellaria heterophylla.
Its positioning is different from bakuchiol.
Instead of being another botanical ingredient added for label appeal, CycloRetin™ is designed to support retinol-related pathways already present in the skin.
According to supplier data from Clariant, CycloRetin™ is positioned as a natural alternative to retinol that helps improve the appearance of wrinkles, firmness, luminosity, and skin sagging.
That distinction matters.
The bakuchiol evidence story includes independent peer-reviewed research.
CycloRetin™ is currently supported by supplier-led in-vitro, ex-vivo, and clinical data.
Supplier data can still be useful.
But it should be identified clearly, not presented as independent academic research.
That is why we talk about CycloRetin™ carefully: as a promising natural active with supplier-backed data, used as part of a broader anti-ageing formula rather than as a single miracle ingredient.
Why We Do Not Formulate for “100% Natural” at Any Cost
Could we make a formula that is 100% natural origin?
Yes.
But that is not always the best goal.
A formula can be 100% natural and still be poorly designed.
It can be too fragrant, too active, too unstable, too weak, or simply not right for sensitive skin.
At 28N, we do not formulate for purity theatre.
We formulate for skin.
That means we look at the full formula: natural-origin content, evidence, tolerance, stability, texture, skin feel, and visible results.
For A⁶, that meant combining natural and natural-derived ingredients with selected synthetic peptides that support the appearance of expression lines.
For B⁶, that meant creating a 96.48% natural-origin brightening formula designed to support a brighter, clearer-looking, more even-looking complexion while staying compatible with daily use.
Different formulas.
Different functions.
Same philosophy.
Evidence over ideology.
The Results Matter Too
Natural-origin percentage tells you something about where a formula comes from.
It does not tell you everything about what the formula can do.
That is why we also test.
In our independent 28-day in-vivo study, A⁶ Anti-Ageing Formula was measured using precision skin imaging tools.
When paired with Vitamin C Booster, the study showed visible improvements in wrinkle volume, wrinkle area ratio, and wrinkle depth by Day 28.
In our independent 28-day in-vivo study, B⁶ Brightening Formula was measured across visible brightness, gloss, dark spot appearance, and redness.
The study showed:
Skin brightness increased by 16.39%.
Skin gloss increased by 20.00%.
Visible dark spots decreased by 34.56%.
Visible redness decreased by 34.05%.
When B⁶ Brightening Formula was paired with Vitamin C Booster, skin gloss increased by 40.69%.
That is the 28N approach:
Do not stop at the ingredient story.
Do not stop at the natural-origin percentage.
Look at the formula.
Look at the method.
Look at the visible results.
What 97.43% and 96.48% Actually Mean
A⁶ Anti-Ageing Formula: 97.43% natural origin.
B⁶ Brightening Formula: 96.48% natural origin.
These numbers do not mean every ingredient is natural.
They do not mean there are no synthetic ingredients.
They mean the finished formula has been calculated by weight using the ISO 16128 framework, and that the vast majority of the formula’s content comes from natural or natural-derived sources.
The remaining percentage is not something we hide.
It is where carefully selected performance ingredients can sit.
For us, that is a more honest version of “natural.”
Not perfect-sounding.
Not simplified.
Just transparent.
FAQ
Does 97.43% natural origin mean only 2.57% of the ingredients are synthetic?
Not exactly.
It means that, by weighted formula contribution, 97.43% of the finished product is natural or natural-derived under the calculation method used.
It is not based on the number of ingredients.
A low-level synthetic ingredient may only reduce the final natural-origin percentage by a small amount because it is present at a small percentage of the total formula.
Why does A⁶ include a synthetic peptide?
Because some cosmetic functions are better supported by precise, lab-designed ingredients.
Amplified Argireline® is used in A⁶ to help improve the appearance of expression lines. It is included because of its targeted cosmetic function, not because it helps the natural-origin percentage.
Is synthetic bad for sensitive skin?
Not automatically.
Sensitive-skin suitability depends on the full formula, concentration, supporting ingredients, fragrance profile, pH, texture, and overall design.
Natural ingredients can irritate some skin types.
Synthetic ingredients can be gentle and targeted.
The category alone does not tell the whole story.
Why not make everything 100% natural?
Because 100% natural origin is not always the same as better skincare.
Our priority is to create formulas that are evidence-led, well balanced, and suitable for daily use.
Sometimes that means using natural-origin ingredients.
Sometimes that means using selected synthetic ingredients.
The goal is not to chase a perfect-sounding number.
The goal is to create a better formula.
Is bakuchiol really comparable to retinol?
In a 2019 randomized, double-blind study, bakuchiol 0.5% used twice daily was compared with retinol 0.5% used once daily over 12 weeks.
Both groups showed significant improvements in wrinkle surface area and hyperpigmentation, with no statistically significant difference between the two groups for those outcomes.
The retinol group reported more scaling and stinging.
That is why bakuchiol is one of the natural-origin actives we chose for A⁶.
What is the difference between bakuchiol and CycloRetin™?
Bakuchiol is a plant-derived retinol alternative supported by independent peer-reviewed research.
CycloRetin™ is a Prince ginseng-derived natural active with supplier-backed data, designed to support retinol-related pathways in the skin in a different way.
In A⁶, they are used together as part of a multi-active anti-ageing approach.
The Takeaway
- “Natural” should not be a vague promise.
- It should be something you can explain.
- At 28N, our natural-origin percentages are calculated, not guessed.
- A⁶ Anti-Ageing Formula is 97.43% natural origin.
- B⁶ Brightening Formula is 96.48% natural origin.
- And where we use synthetic ingredients, we say so.
- Because the goal is not to look natural on a label.
- The goal is to formulate with intention.
- Natural-origin where it makes sense.
- Synthetic where the evidence supports it.
- Visible results, measured carefully.
- Powered by knowledge, not hype.
- Patch test before use. For external use only.
The Evidence Behind This Article
For readers who want to go deeper, these are the key standards, studies, supplier references, and 28N research pages behind this article.
- ISO 16128-1:2016 — Cosmetics — Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products, Part 1: Definitions for ingredients.
https://www.iso.org/standard/62503.html - ISO 16128-2:2017 — Cosmetics — Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products, Part 2: Criteria for ingredients and products.
https://www.iso.org/standard/65197.html - ISO/TR 23750:2021 — Cosmetics — Answers to frequently asked questions on ingredient and product characterization according to ISO 16128-1 and ISO 16128-2.
https://www.iso.org/standard/76832.html - Dhaliwal et al., 2019 — “Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing.” British Journal of Dermatology, 180(2), 289–296.
https://pubmed.ncbi.nlm.nih.gov/29947134/ - FDA — “Organic” Cosmetics — FDA guidance on cosmetic organic labeling and the distinction between USDA organic requirements and FDA cosmetic labeling requirements.
https://www.fda.gov/cosmetics/cosmetics-labeling-claims/organic-cosmetics - FDA — Cosmetics Labeling Claims — General FDA guidance on cosmetic labeling claims.
https://www.fda.gov/cosmetics/cosmetics-labeling/cosmetics-labeling-claims - UK ASA/CAP — Beauty and Cosmetics: General — Advertising Standards Authority guidance on substantiating cosmetic claims, including natural, organic, and performance-related claims.
https://www.asa.org.uk/advice-online/beauty-and-cosmetics-general.html - CTPA — ASA Ruling on Misleading and Unsubstantiated Claims — Industry summary of an ASA ruling relating to misleading and unsubstantiated natural and physiological cosmetic claims.
https://www.ctpa.org.uk/news/asa-ruling-on-misleading-and-unsubstantiated-claims-7394 - Clariant — CycloRetin™ Natural Active — Manufacturer product page for CycloRetin™, the Prince ginseng-derived natural active used in A⁶ Anti-Ageing Formula.
https://www.clariant.com/en/Business-Units/Care-Chemicals/Personal-Care/Actives-and-Natural-Origins/Active-Ingredients/Natural-Actives/CycloRetin - SGS / Beta Analytic — ASTM D6866 Explainer — Background on radiocarbon-based biobased-content testing.
https://www.betalabservices.com/biobased/astm-d6866.html - 28N Skincare — A⁶ Anti-Ageing Formula — Product page citing 97.43% natural origin under ISO 16128 and the use of CycloRetin™, Bakuchiol, and Amplified Argireline®.
https://www.28nskincare.com.au/products/anti-aging-serum - 28N Skincare — B⁶ Brightening Formula — Product page citing 96.48% natural origin under ISO 16128.
https://www.28nskincare.com.au/products/brightening-serum - 28N Skincare — About Us — Brand page supporting the over 95% natural-origin and science-led positioning.
https://www.28nskincare.com.au/pages/about-us - 28N Skincare — Amplified Argireline® — 28N research page summarising supplier data on Amplified Argireline®, including potency and SNARE-complex binding claims.
https://www.28nskincare.com.au/blogs/ingredients-glossary/amplified-argireline%C2%AE-the-botox-alternative-for-firmer-wrinkle-free-skin - 28N Skincare — Bakuchiol vs Retinol — 28N research page explaining bakuchiol as a plant-derived retinol alternative and summarising the Dhaliwal et al. study.
https://www.28nskincare.com.au/blogs/ingredients-glossary/bakuchiol-vs-retinol - 28N Skincare — CycloRetin™ Prince Ginseng — 28N research page explaining CycloRetin™ as a Prince ginseng-derived natural active.
https://www.28nskincare.com.au/blogs/ingredients-glossary/blogs-news-cycloretin-prince-ginseng - 28N Skincare — 28 Days to Youth — A⁶ Anti-Ageing Formula research page summarising the 28-day in-vivo wrinkle imaging results.
https://www.28nskincare.com.au/blogs/news/28-days-to-youth - 28N Skincare — B⁶ Brightening Formula Study — B⁶ research page summarising the 28-day in-vivo results for brightness, gloss, visible dark spots, redness, and the B⁶ + Vitamin C Booster gloss result.
https://www.28nskincare.com.au/blogs/news/b6-brightening-formula-study