Reserve
It starts as rambutan peel — the red, hairy shell of a tropical fruit that the food industry throws away at a rate of roughly a million tons a year. We buy it, and we pull the good part out.
Most botanical extraction runs on methanol or ethanol. Ours uses a natural deep eutectic solvent — a solvent built from things you could eat. The method was published in Food Chemistry in 2025.
The compounds are geraniin, corilagin and gallic acid, tested against four stressors: infrared heat, ultraviolet light, a surfactant, and retinol.
Every ingredient, and why it's there.
Rambutan Reserve is the signature of the formula. The ingredients around it are grouped by what each does for how skin looks and feels.
Cool-down botanicals
Five roots and barks that Korean herbal tradition groups as cooling. Here, they are for comfort on skin that runs warm.
Bupleurum RootBupleurum Falcatum Root ExtractHelps skin that feels tight and easily bothered feel calmer.
Coptis RootCoptis Chinensis Root ExtractHelps keep skin looking balanced and less shiny.
Phellodendron BarkPhellodendron Amurense Bark ExtractHelps skin look calmer and feel smoother.
Angelica RootAngelica Dahurica Root ExtractHelps skin look brighter and more even in tone.
GallnutRhus Semialata Gall ExtractA natural tannin with a light astringent feel. Helps texture look refined and pores look smaller.
Comfort and redness
Well-studied skincare staples for skin that turns pink and warm.
AloeAloe Barbadensis Leaf JuiceFeels cool on contact and soothes skin that feels warm.
NiacinamideNiacinamide (vitamin B3)Helps reduce the look of redness and blotchiness, and helps skin hold on to moisture.
PanthenolPanthenol (provitamin B5)Soothes skin that feels dry and rough, and leaves it softer.
Vitamin ETocopheryl AcetateAn antioxidant that helps defend skin against the look of everyday environmental stress.
Water and bounce
For skin that loses water faster than it used to.
Hyaluronic acid, two sizesHigh and low molecular weightLarger molecules hold water at the surface; smaller ones reach the upper layers of skin. Plumps the look of fine lines.
Rehmannia RootRehmannia Glutinosa Root ExtractA root long valued in Korean herbal tradition. Helps skin look smoother and more supple.
Cuscuta SeedCuscuta Chinensis Seed ExtractA seed extract from the same tradition. Helps skin look brighter and more radiant.
Rambutan PeelNephelium Lappaceum Peel ExtractThe source of Rambutan Reserve. Rich in polyphenols; helps skin look firmer and more resilient.
These notes describe why each ingredient is in the routine. Only the figures under Clinical results come from testing Kestia itself. Kestia is a cosmetic, intended to affect the appearance and feel of skin only.