Skin Care & Cosmetic Ingredient Glossary (L – O)

Lactic Acid 

Lactic acid, derived from fermented milk, is one of the most researched alpha hydroxy acids (AHAs), which breaks down the bonds between skin cells so that dead skin cells can be sloughed away to reveal brighter, more even-toned skin.

It is part of the skin's natural moisturizing factors (NMFs), which occur naturally in our skin and keep the outer layer hydrated and protected.

Korean skin care products with lactic acid are Some By Mi AHA BHA PHA 30 Days Miracle Bar and Cosrx AC Collection Calming Liquid Intensive.

*Syn: Sodium Lactate 

Lanolin

Lanolin is a waxy substance secreted by the sebaceous glands of sheep and is also known as lanolin or wool fat. Lanolin acts as an effective emollient - a lubricant on the skin that helps lock in moisture and soften dry, rough, flaky and irritated skin.

Lavender Flower Oil and Extract 

Lavender oil is commonly known for its fragrance and therapeutic components, and works wonders on inflammation and kills bacteria due to its antiseptic and anti-inflammatory properties.

The flower extract is less potent than the essential oil and is made from dried flowers and oils of the lavender plant. 

*Syn: Lavandula Angustifolia, Lavandula Officinalis

Licorice Root Extract 

Licorice is derived from the plant Glycyrrhiza Glabra, which means "sweet root" in Greek, and has a soothing and skin-brightening effect on dull, lackluster, sensitive and reddened skin. 

Liquorice root contains powerful active ingredients - antioxidants to neutralize free radicals and glycyrrhizin to relieve redness and swelling due to anti-inflammatory properties.

Glabridin and liquiritin help lighten sun spots and dark circles by interrupting the enzyme tyrosinase, which is responsible for the formation of pigment in response to sun exposure. This, in turn, reduces hyperpigmentation. Licochalcone, found in licorice root, has been shown to control the oil content of the skin.

For products containing licorice extract, check out Pyunkang Yul Acne Cream or The Saem Natural Rice Mask Sheet.

*Syn: Liquorice, Glycyrrhiza Glabra

Linoleic Acid

Linoleic acid is an omega-6 plant-based essential fatty acid (EFA) - it is essential for human health, but is not produced by the body, making it different from oleic acid.

Found in seeds, nuts and other vegetable oils such as safflower, rosehip, evening primrose and hemp seeds. It helps restore the natural barrier function and acts as an essential building block for ceramides - one of the moisturizing agents.

The polyunsaturated oil is lightweight and easily absorbed by the skin without clogging pores, making it suitable for combination, oily and congested skin.

*Syn: Alpha-linolenic Acid

Lentil Seed Extract  

Lentil extract is a natural active ingredient that has nice moisturizing benefits and works as a skin conditioning and a protecting agent.

Lentil seed is rich in vitamin B5 and oligosaccharides — which help reduce the appearance of dilated pores, shininess, and refines the look of skin’s texture.

*Syn: Lens Esculenta

Mandelic Acid 

Mandelic acid, derived from bitter almonds, is an Alpha Hydroxyl Acid (AHA) that works to accelerate cell turnover by gently lifting off dead skin cells; however, its large molecular size makes it gentler than other AHAs, such as glycolic acid.

The chemical exfoliant helps brighten skin tone, fade unwanted acne scars and dark spots, and minimize the appearance of pores, fine lines and wrinkles. 

Marula Oil 

Naturally rich in antioxidants, essential fatty acids, amino acids, vitamin C and E, Marula oil has been hailed for its anti-aging, emollients, and anti-inflammatory and antibacterial properties.

It is derived from either the nut or the soft kernel seeds of the fruits of the African Marula trees. Marula oil is lightweight and absorbed quickly into the skin, creating a light layer on top of the skin to lock in moisture.

*Syn:  Sclerocarya Birrea

Menthol 

Typically derived from plants such as peppermint and eucalyptus, menthol is found in facial toners, shaving gels, and moisturizers, but usually in synthetic form.

Menthol provides a cooling and fresh sensation while functioning as a topical analgesic (pain reliever), antifungal agent, and penetration enhancer.

One thing to keep in mind is that menthol can cause eye and skin irritation and/or be sensitizing, especially for sensitive, rosacea and acne-prone skin. 

Mexoryl 

Mexoryl is widely used in sun creams and lotions due to its excellent UV-absorbing and photostable capabilities. There are two types of Mexoryl and both are L'Oréal Group exclusive sunscreen agents- Mexoryl SX is water soluble and protects the skin from UVA rays, while Mexoryl XL is lipid soluble and protects the skin from both UVA and UVB rays.

*Syn: Mexoryl XL: Drometrizole Trisiloxane / Mexoryl SX: Ecamsule, Terephthalylidene Dicamphor Sulfonic Acid

Micellar Water 

Made up of a mix of purified water, hydrating agents and micelles — tiny particles of cleansing oils that are attracted to dirt, makeup, and grime and cleanse the skin without drying out the skin.

Mineral Oil

Like petroleum jelly, mineral oil is a byproduct of the petroleum distillation and both are considered petrochemicals.

As an effective emollient and an occlusive agent, mineral oil has been shown to improve skin softness and barrier function by forming a film on the skin’s surface.

Moringa Seed Oil and Extract

Extracted from the seeds of Moringa tree, which is beginning to gain more popularity as “the miracle tree”. Moringa oil is a powerhouse of antioxidants, omega fatty acids, and amino acids that restore the skin’s barrier and seal in hydration.     

Morniga oil is similar to the oil our body produces, making it easily absorbed and keeping the skin nourished and balanced. It is also high in cytokinins, vitamins (A, C, E), and zeatin which helps in promoting cellular growth and delaying signs of aging. 

E Nature Moringa Cleansing Balm is a great face cleanser/makeup remover for the first step of double cleansing method.

*Syn: Moringa Oleifera

Niacinamide

Niacinamide, a form of water-soluble vitamin B3, works to diminish the appearance of aging, enlarged pores, hyperpigmentation, and improves uneven skin tone and texture, as well as the skin's barrier function.

Vitamin B3 is rich in antioxidants and anti-inflammatory properties that help protect skin from environmental damage, boost hydration levels and cell turnover, while soothing redness and irritation.

Korean products with niacinamde are Missha Time Revolution Night Repair Probio Ampoule, Pyunkang Yul Black Tea Time Reverse Eye Cream, Benton Snail Bee High Content Skin Lotion, and Cosrx BHA Blackhead Power Liquid.

*Syn: Nicotinamide, Nicotinic Acid Amide, Myristyl Nicotinate

(Related blog post: 9 Best Ingredients To Brighten Dull, Tired Skin)

Olive Oil

Olive oil, extracted from the fruit of the olive tree, is rich in the fatty acid squalene, which traps water in the skin and strengthens the skin barrier - making it ideal for extremely dry skin (especially on the body).

For oily and acne-prone skin, keep in mind that it is moderately comedogenic - meaning it can clog and cause breakouts. 

*Syn: Olea Europaea

Oleic Acid 

Oleic acid, which is rich in omega-9 fatty acids, is naturally produced by our bodies and is found in various animal and vegetable oils such as sea buckthorn, olive, marula, grape and sunflower seeds. 

Oleic acid is thicker and feels richer than linoleic acid and is better suited for dry, aging and sensitive skin. This monounsaturated fatty acid is a great source of plant-based nutrients, and combining it with other ingredients boosts its ability to strengthen the skin barrier and soothe irritation.

Occlusive(s)

Occlusive agents increase the moisture content of the skin by forming a film that prevents water loss from the epidermis. Thanks to their thick and rich texture, occlusive moisturizers are best suited for very dry, mature and damaged skin

However, if your skin is prone to breakouts, it is important to make sure that the ingredients are non-comedogenic -which means it doesn’t congest pores. 

Common occlusive ingredients include waxes, petrolatum, silicones, and dimethicones. Please note that some ingredients may have more than one moisturizing property (humectant, emollient, occlusive properties) at the same time - such as lanolin, mineral oil, and shea butter.

Octinoxate (OMC)

Octinoxate is a chemical filter that acts as a UVB absorber and is commonly used in sunscreens, shampoos, nail polish, lipsticks, hair dyes and other beauty products.

Octinoxate filters UVB rays from the sun and has minimal protective effect against UVA rays. Therefore, in order to get broad-spectrum protection, octinoxate is often combined with zinc oxide or avobenzone or another chemical UVA filter.

Despite being a conventional ingredient in the cosmetics industry, it is increasingly associated with numerous risks to animals and the environment (and possibly to humans, as it is a hormone disruptor). To date, however, there has been little in-depth research.

In general, it is safe to use in low concentrations—according to the U.S. FDA, the recommended use level is up to 7.5 percent.

*Syn: Ethylhexyl Methoxycinnamate, Octyl Methoxycinnamate. Escalol 

Octocrylene

As an oil-soluble sunscreen agent, octocrylene absorbs UV rays and protects the skin from the sun's harmful effects, such as premature aging, and reduces the risk of skin cancer; however, it is considered safe in cosmetic products at concentrations up to 10%.

Oxybenzone

As an ultraviolet light absorber, Oxybenzone absorbs UVB and short-wave UVA, preventing potential damage from sun exposure. The active ingredient also acts as a photostabilizer and is one of the most commonly used ingredients in commercial chemical sunscreens.

Despite its widespread use, some studies have raised concerns about the use of oxybenzone because it is absorbed by the skin and remains in our bodies for an unknown amount of time. In addition, it has been associated with a high rate of skin reactions and allergies.

*Syn: Benzophenone-3