Pseudolarix Bark Extract (土荆皮) — Naming, INCI Status and Safety Data

Of the three botanicals in our nail care cream, golden larch bark is the one that makes the formula specific to nails and feet. It is also the one that takes a regulatory reviewer longest, for two reasons: its naming is unsettled in cosmetic databases, and its main constituent is a compound the safety assessor will want measured.

Every ingredient on an EU, UK or US cosmetic label is declared by its INCI name. When we searched CosIng, the European Commission’s ingredient inventory, we found no entry filed under the genus Pseudolarix. The ingredient can still be used. The naming has to be resolved before the dossier is filed.

• First, have your reviewer search CosIng and the Personal Care Products Council dictionary again. Names get assigned, and this page records what we found, not a permanent fact.
• If there is still no entry, the formal route is an INCI name application to the Personal Care Products Council, which runs the international naming system.
• Your responsible person decides how the ingredient is declared in the meantime. Regulation 1223/2009 requires the common ingredient name, and where none exists, a term from a generally accepted nomenclature.

The Larix trap

The second risk is a wrong declaration. Pseudolarix means “false larch”, and several databases file it next to, or under, the true larches. CosIng does contain entries for Larix kaempferi, the Japanese larch, and a reviewer searching on the species epithet “kaempferi” will find them. They describe a different tree in a different genus.

The shared epithet comes from the same 17th-century naturalist, Engelbert Kaempfer, which is why the two get crossed. A declaration under a Larix entry would misdescribe the ingredient on your own label.

The bark’s characteristic constituents are the pseudolaric acids, a family of diterpenoids. Pseudolaric acid B is the main one, and it is well studied: it is cytotoxic in cell studies and has been researched as an anticancer and anti-angiogenic compound. Research has also found that its content differs between parts of the tree, which matters for a specification.

This does not decide the safety question on its own. It sets what the assessor will ask for first:

• Pseudolaric acid B content in the extract, with the analytical method, and a specification limit so batches can be held to it.
• Extract concentration in the finished cream.
• The exposure scenario, which here includes keeping the cream under a wrap for five to seven days. Occlusion raises skin penetration, and an assessment written for an ordinary leave-on cream does not cover it.
• Confirmation that the label carries external-use-only and keep-out-of-reach-of-children wording, consistent with how the herb is treated traditionally.

Sophora flavescens is a general skin herb, and Impatiens balsamina carries a nail-dyeing heritage. 土荆皮 is the herb Chinese practice reaches for specifically for the nails and the skin of the feet. Without it, the formula is a salicylic acid cream with two botanicals added.

For a brand, that specificity is the product story. Start the regulatory work on this ingredient first, with our specification in hand.

Start the regulatory work on this ingredient

Send us your target market and we will issue the extract specification, including the pseudolaric acid figure from the batch documentation, with the full breakdown of the finished cream.

All sourcing guides

Sources and where to check

• European Commission — CosIng cosmetic ingredient database — searched under Pseudolarix and Larix, October 2026
• Regulation (EC) No 1223/2009 on cosmetic products — Article 19(1)(g) on ingredient names
• Pseudolaric acids: isolation, bioactivity and synthetic studies — Natural Product Reports, 2010 review
• Our formulation overview — the keratolytic base and all three botanicals