Cuticle oil is a light blend of plant oils, usually built on jojoba, sweet almond or vitamin E, that is applied daily to the skin around the nail and to the nail plate so both stay flexible and the nail bends before it chips.
Also known as: nail oil, cuticle serum, nagelriemolie, jojoba nail oil
Cuticle oil is the simplest nail treatment and the one manicurists rate highest. A drop is massaged into the eponychium, the skin fold at the base of the nail, the side walls and the plate itself. Jojoba is the classic base because its structure is close to the skin's own sebum and its small molecule penetrates well; sweet almond oil and vitamin E are the usual partners (Wallpaper).
The oil does two jobs. It keeps the nail plate supple so it bends under a knock, which is why oiled nails chip less than dry ones; Manucurist puts daily oil in its standard routine for making polish last (Manucurist). It also keeps the skin around the nail intact. Dermatologist Dr Hadley King advises keeping that skin moisturised so bacteria and other pathogens are less likely to get in (Today).
Use it once or twice a day, on bare nails and over polish alike, since the oil feeds the skin and the exposed plate and does no harm to a dried lacquer. Wait a few minutes after applying polish before the first drop. In winter, or for anyone who washes their hands often, an occlusive balm over the oil at night traps the moisture in.
Formats range from a chemist's dropper to a pen with a brush tip, and from a few euros to the 100 percent natural cuticle oil Hermès sells at $70. The ingredient list matters more than the price: a short list of plant oils with tocopherol (vitamin E) and no water is the sign of a proper cuticle oil.