Koyu Science

What wecan prove

Every Koyu formula is built on the same ingredient, from the same farm. Wagyu tallow works because of what it is made of, not because of how it sounds — and this page sets out the composition, the testing and the sourcing behind all of it.

It also sets out what we don’t claim. A brand that only publishes its best numbers isn’t publishing evidence.

Provenance over promises

What skin already makes

One ingredient,every formula

Our Formula

Built like skin.

Saturated and monounsaturated — the same character as the lipid you already make.

Our Formula

Clean ingredients, visible results

Every formula is dermatologist-tested and free from parabens, sulfates, and synthetic fragrance.

Ingredients

Short lists, on purpose.

Every ingredient earns its place, or it isn't in the jar.

01 Provenance over promises

We don’t ask you to take our word for it.

Every product traces back to a single origin, a traceable source and a process we can stand behind, start to finish. Commodity tallow is blended from countless sources nobody can name. Ours has an address.

From the farm

One lineage, one origin farm, traceable start to finish — raised under welfare standards Japan has spent generations writing down.

Single origin, by choice and by paperwork.

From the farm

Paired with actives chosen for a specific purpose — peptides, hyaluronic acid, ceramides. Nothing rushed, nothing cut, nothing added to pad a label.

Formulated and finished in London.

To the skin

It melts at skin temperature and works with your skin’s own chemistry, rather than sitting on top of it waiting to be absorbed.

Recognised, not resisted.

What skin already makes

Your skin produces its own lipid layer every day. Roughly a third of it is triglycerides, and almost a quarter is wax esters — the same class of molecule as jojoba.

That matters, because the case for any facial oil or balm rests on how close it sits to this. Skin surface lipid is mainly long-chain, mainly saturated and monounsaturated. It is not a polyunsaturated system.

Human skin surface lipid, by class

% of total · healthy adults · mean ± SD

Triglycerides

34± 6.5

Free fatty acids

24± 6.1

Wax mono-esters

24± 2.1

Squalene

120.6

Cholesterol & esters

010203040

Source: Koyu Science research

Where our tallow sits

Tallow is not one material. The difference between Koyu’s and the commodity version is not a matter of grade — it is a matter of whether anyone can tell you where it came from.

Koyu Wagyu tallow

Commodity tallow

Botanical oils

Origin

One farm, one lineage

Pooled, multiple abattoirs

Varies by crop and season

Traceable to source

Yes, by batch

Sometimes

Lipid character

Saturated and monounsaturated

Often polyunsaturated-led

Welfare standards

Japanese Wagyu husbandry

Unspecified

Not applicable

Batch analysis published

Yes — per batch

Rarely

By-product of an existing system

No — grown for purpose

03

One ingredient,every formula

There is no “tallow range” and a separate everything else. The same single-origin tallow sits at the base of every Koyu product. What changes around it is what each one has to do.

The constant

One lineage, one origin farm, one rendering process — identical in the hand cream and the night cream. Saturated and monounsaturated, in the same character as the lipid your skin makes for itself.

It is the only ingredient that appears in everything we sell. If it ever isn’t traceable, there is no product.