Lipstick is a widely used cosmetic product designed to enhance the appearance of the lips by adding colour, shine, and sometimes providing moisturisation or sun protection. The basic formulation of a traditional lipstick consists of an anhydrous (water-free) paste made up primarily of oils and waxes, in which pigments and other colouring agents are finely dispersed. This anhydrous nature is crucial for the product’s solid form and its ability to adhere to the lips, which themselves have a unique structure comprising both mucosa and skin.
Waxes form the structural backbone of the lipstick, typically comprising around 15% of the formulation. These are solid at room temperature and must be melted during the manufacturing process. Waxes provide hardness to the lipstick stick, ensuring it does not break during application, and contribute to the product’s creaminess and matte appearance. A variety of waxes can be used, including those of vegetable (e.g., candelilla wax), animal (e.g., beeswax), and synthetic origin. Modern lipstick manufacturing often utilises specific fractions of waxes with defined fusion points, which are purer and more odourless than traditional natural waxes.
Waxy pastes, often making up about 20% of the formulation, help to lubricate the lipstick upon application, contributing to a smooth glide and even colour distribution.
Oils constitute a significant portion of the lipstick formula, typically around 30%, and serve as the primary medium for dispersing the pigments and other colouring agents. Various types of oils, both natural and synthetic, are used, contributing to the lipstick’s texture, emolliency, and shine.
Texturing agents, usually around 10% of the formulation, are added to further improve the lipstick’s feel and application properties.
Colouring agents, including pigments and/or pearlescent pigments, are essential components, typically making up about 20% of the lipstick. Pigments are solid, insoluble particles that provide the main colour to the lipstick and can offer varying degrees of coverage, capable of hiding the underlying lip colour. International regulations strictly limit the types and concentrations of pigments that can be used in lipsticks due to the risk of ingestion. Pearlescent pigments (or pearls) are used to impart a lustrous, shiny effect to the lipstick. These are often metallic oxides coated with materials like mica. The formulation process involves carefully milling the coloured powders to ensure fine and even dispersion within the oil and wax matrix, resulting in a natural-looking tinted film upon application. Formulators work within the defined scope of permitted colorants to develop a wide range of shades that match diverse skin tones and consumer preferences.
Preserving agents (around 1%) are crucial for stabilising the formulation and preventing microbial contamination, given the organic nature of many lipstick ingredients. Antioxidants (also around 1%) may be included to prevent the degradation of oils and waxes, maintaining the product’s quality and colour over time.
Perfume (around 1%) is added for aesthetic reasons, providing a pleasant scent to the product.
Active ingredients, included as needed, can provide additional benefits. UV filters are often incorporated to protect the lips from sun damage, which can contribute to long-term ageing. Other active ingredients, such as vitamins (e.g., vitamin A, vitamin E, vitamin C), may be included with claims of anti-ageing or moisturising properties, although they must be present at effective concentrations to substantiate these claims.
Lip glosses and lip brilliants are related lip makeup products that generally have lower covering qualities than traditional lipsticks but are formulated to reflect light and give the lips a shiny appearance. These formulations may have a different balance of oils, waxes, and polymers to achieve their characteristic glossy texture.
The development of a lipstick involves careful consideration of the interaction between these various ingredients to achieve the desired colour, texture, application, wear properties, and stability. Before being marketed, lipsticks undergo a battery of tests to confirm their safety and performance, including assessments of ingredient safety and toxicological profiles, stability under various conditions, and microbiological preservation. In conclusion, lipstick is a sophisticated cosmetic product based on an anhydrous paste of oils and waxes that serves as a vehicle for pigments and other colouring agents. The specific blend of waxes provides structure, oils aid in pigment dispersion and emolliency, and pigments impart colour. Preservatives and antioxidants ensure product integrity, while perfume enhances the user experience. Increasingly, active ingredients like UV filters and vitamins are being incorporated for added skincare benefits, reflecting the evolving demands of consumers.