The composition of cosmetics is very complex and varies with different types. Most cosmetics are processed from the cosmetic matrix (base) plus some other necessary ingredients (additives). Cosmetic substrates are the basic raw materials of cosmetics. They are mainly oily raw materials, including oils, waxes, hydrocarbons, and higher fatty acids and higher alcohols that make up these ingredients.

Salicylic acid

Also known as β-hydroxy acid (BHA, beta hydroxy acid), salicylic acid has multiple functions and can solve various problems that cause acne. Dermatologists have used salicylic acid to exfoliate skin for decades, but it's also an anti-irritant ingredient. Salicylic acid is similar in structure to aspirin (they are both salicylates, and aspirin is also named acetylsalicylic acid), so it also has anti-inflammatory properties. Salicylic acid is also antiseptic, which is a big reason to use it to treat acne. In addition, studies have found that it can increase skin thickness, improve skin barrier function, and promote collagen synthesis. In addition, salicylic acid at a concentration of 8% to 12% is an effective exfoliating treatment, and salicylic acid at a concentration of 0.5% to 2% is milder in nature, similar to AHAs. In addition, salicylic acid can penetrate deep into the pores (AHAs cannot) and remove the aging keratinocytes on the surface of the skin and in the pores, so it can be used to effectively fight acne.

AHA

Also named alpha hydroxy acid, AHAs can be extracted from various plants or milk, but 99% of AHAs in cosmetics are synthetic. AHAs in low concentrations (less than 3%) can act as water retainers. AHAs have an exfoliating effect when the concentration is above 4% and the pH is between 3 and 4. The most effective and most researched AHAs are glycolic and lactic acids. Malic acid, citric acid, and tartaric acid are also effective, but they are comparatively less stable and not suitable for use on the skin; and there are few studies to prove that they are beneficial to the skin. AHAs can irritate the mucous membranes and cause inflammation. After using AHAs, the living epidermal cells in the epidermis and the glucosaminoglycan in the dermis will increase. Numerous studies report the anti-aging benefits of using AHAs (including glycolic acid and lactic acid) on the skin. AHAs can remove sun-damaged keratinocytes on the surface of the skin, but this layer of keratinocytes has a certain sun protection effect, so the skin is more likely to be sunburned after using AHAs. However, this problem does not occur with sunscreen products.

Retinol

If the weakening of the deep skin connective tissue of the thighs is the main cause of cellulite (and the excess accumulation of fat), then improving the structure of the skin connective tissue will naturally improve cellulite, and now more and more research supports this idea. Retinol is one of the substances known to improve skin structure. Of all the anti-cellulite products, those fortified with retinol should be the first choice. However, most related products contain very little retinol, and retinol is easily decomposed in the air, but the packaging of most products cannot ensure the stability of retinol.

Avobenzone

Avobenzone is a synthetic sunscreen ingredient (full name Butyl Methoxydibenzoylmethane), which can protect against full-wavelength UVA rays.

Titanium dioxide

Titanium dioxide is an inert mineral used in cosmetics as a thickener, whitener, lubricant, and sunscreen. It protects the skin from UVA and UVB rays and is non-irritating to the skin.