Formulating for sensitive skin means designing out likely irritants and allergens from the start, then proving the result on real skin. "Hypoallergenic" has no legal definition in New Zealand or Australia, so the claim is only as strong as the evidence behind it. A sensible plan combines a lean ingredient list, preservative efficacy testing and a dermatologist-supervised patch test or HRIPT.
Sensitive skin is one of the most requested briefs we see from indie founders, and one of the easiest to get wrong. A short ingredient list is a good start, but it is not the same thing as a product that is gentle, stable and defensible on the label. This guide walks through what formulators actually do, what the claims mean, and what to budget for.
What does "formulating for sensitive skin" actually involve?
There is no single "sensitive skin" ingredient list. Instead, a chemist works through four levers:
- Fewer, better-chosen ingredients. Every extra ingredient is another chance for a reaction. We justify each one by its job in the formula.
- Gentle surfactants and emulsifiers. Cleansers and emulsions are where much of the irritation risk sits, so system choice matters as much as actives.
- Controlled pH and active levels. Even a well-tolerated active can sting if pH or concentration is off.
- A deliberate fragrance decision. Many sensitive-skin brands go fragrance-free, which removes a major source of known allergens.
Botanical extracts and essential oils are worth a particular look. "Natural" is not a synonym for "gentle", and several plant materials are recognised contact allergens.
Is "hypoallergenic" a regulated claim in NZ and Australia?
No. We are not aware of any legal definition of "hypoallergenic" in NZ or Australia, and the same is true in the US, where brands can use the word without submitting evidence first. That does not make it a free-for-all. In Australia, claims fall under the Australian Consumer Law, and in New Zealand under the Fair Trading Act, both of which prohibit misleading claims. If a regulator or competitor challenges you, you need evidence on file.
Our guide to cosmetic claims substantiation covers the wider rules. For sensitive-skin claims specifically, the practical standard is a test report you could hand to a regulator.
What is the difference between "dermatologically tested" and "hypoallergenic"?
They sound similar but rest on different evidence:
- Dermatologically tested is typically supported by a patch test on a panel of volunteers, with a dermatologist grading skin reactions after a set exposure period. Providers describe panels of roughly 10 to 100 people.
- Hypoallergenic is usually supported by a Human Repeat Insult Patch Test (HRIPT), which repeats applications over several weeks to assess both irritation and sensitisation. Panels commonly run from 50 to 200 participants.
A report signed by a dermatologist is the document that makes either claim defensible. Because the claim attaches to the finished product, the test is run on your final formula, not on the raw materials.
Which ingredients should sensitive-skin brands be careful with?
Rather than a banned list, we think in terms of risk and dose:
- Fragrance and essential oils. Under EU rules, the list of fragrance allergens that must be declared has expanded to more than 80 substances (Regulation (EU) 2023/1545). New products placed on the EU market after 31 July 2026 need to comply, and existing products have until 31 July 2028. If you plan to export, a fragrance-free or low-allergen approach keeps labelling simpler.
- Strong actives. Acids and retinoids need careful pH, dose and delivery. See our guides to exfoliating acids and retinol.
- Preservatives. You cannot skip them, because an unpreserved water-based product is a microbial risk. The goal is the lowest effective system, proven by preservative efficacy testing.
- Botanical extracts. Include them for a reason, at a sensible level, and check their allergen profile.
How do you build a sensitive-skin product with The INCI Lab?
It depends on how much you want to own and how fast you want to move:
- Ask The Chemist (30 minutes, NZ$150) is a quick way to sense-check an existing formula or ingredient list.
- The Accelerator (4 to 6 months, starting from NZ$2,000 to NZ$5,000) suits a semi-custom, gentle-skincare launch.
- The Visionary (9 to 12 months, starting from NZ$4,000) is for a bespoke formula where you own the IP in full.
- Ready-to-Go offers pre-formulated, stability-tested bases for the quickest route to market.
Across all routes, minimum order quantities start at 100 to 500 units, and we prepare compliance documentation for NZ, Australia, the EU and the US, including AICIS considerations for Australian markets. Fragrance-free, vegan and cruelty-free formulas are all well within our capability. Preservative efficacy testing is NZ$1,200 per formula. Clinical patch testing is run by an external provider, so we help you scope it and interpret the results. Get in touch to talk through your brief.
Frequently asked questions
Can I call my skincare "hypoallergenic" in New Zealand or Australia?
You can, but there is no official definition, so you carry the burden of proof. Consumer law prohibits misleading claims, so keep a test report, ideally an HRIPT, on file before the word goes on your label.
Is fragrance-free the same as hypoallergenic?
No. Removing fragrance lowers one common risk, but other ingredients can still cause reactions. Hypoallergenic is a claim about the finished product, backed by testing.
What is an HRIPT?
A Human Repeat Insult Patch Test applies a product repeatedly to volunteers' skin over several weeks to check for irritation and sensitisation. It is commonly used to support hypoallergenic claims.
Do natural ingredients suit sensitive skin better?
Not automatically. Some plant extracts and essential oils are known allergens. We choose ingredients on evidence and dose, not on whether they are natural.
Does a sensitive-skin product still need preservatives?
Yes, if it contains water. The aim is the gentlest system that passes preservative efficacy testing, not no preservative at all.
How low can my first batch be?
Minimum order quantities start at 100 to 500 units depending on the route, so you can validate a sensitive-skin range without a large upfront inventory.