A Comprehensive Guide to Popular Skincare Additives: Acids, Peptides, Vitamins & More

Skin care is essential for maintaining fresh, healthy, and clear skin. Whether new to skincare or experienced, it’s important to know which ingredients serve specific purposes. If you have a specific skin condition, always check the ingredients in your skincare products.

With so many skincare products available, the variety of ingredients can feel overwhelming. Most are added to improve the product or carry the active ingredients that deliver results.

An active ingredient is one that has been proven to benefit the skin. For instance, Vitamin A rejuvenates wrinkles and fine lines. Knowing the roles of active ingredients helps you choose the best product for your needs.

Products with AHA have surged in popularity in recent years. Lotions and creams containing AHA can help reduce wrinkles, fine lines, irregular pigmentation, age spots, and enlarged pores.

As for side effects, this may include sun sensitivity and mild irritation, which can be avoided by applying sunscreen every morning. You can avoid skin irritation by starting with a product with a maximum AHA concentration of 10-15%. A good piece of advice is to start by applying the product every other day and gradually work up to daily use to help your skin get used to it.

Glycolic acid is an AHA that exfoliates the skin and boosts collagen production. While it helps clear pores, smooth fine wrinkles, and hydrate, lactic acid—another AHA—also provides exfoliation and moisturization. Typically, glycolic acid penetrates more deeply, while lactic acid is milder and suitable for sensitive skin. Both target similar concerns, but their strength and tolerances may vary.

If you struggle with acne scarring, acne, fine lines, wrinkles, pigmentation issues, or skin texture and hydration concerns, look for products with retinol. Derived from Vitamin A, retinol is common in anti-aging products. Its small molecular structure helps it reach the lower layers of the skin, boosting the production of elastin and collagen to strengthen skin flexibility.

Products containing hydroquinone are called lightening agents or bleaching creams. They lighten hyperpigmentation and age spots, often resulting from hormone therapy or pregnancy. Dermatologists may prescribe stronger concentrations if over-the-counter options are ineffective.

Hydroquinone is sometimes combined with sunscreen because direct sunlight exposure can cause skin hyperpigmentation. It is recommended to first test products containing hydroquinone with a patch test on a small area of the skin. This is because some people are allergic to it.

First discovered in 1989, kojic acid works similarly to hydroquinone, as both are used to treat pigmentation and age spots. However, kojic acid is derived from a fungus, and both ingredients lighten skin by slowing melanin production. Hydroquinone is often stronger, while kojic acid is used as a gentler alternative. With prolonged use, both can increase sun sensitivity.

To improve the color and texture of sun-damaged skin, try products with salicylic acid. It helps remove dead skin cells and penetrates oil-filled follicles to help with acne.

Skin care products with salicylic acid are available over the counter or by prescription. Unlike alpha-hydroxy acids, salicylic acid is less likely to cause irritation while offering similar improvements in skin color and texture. Salicylic acid is oil-soluble, allowing it to penetrate oily pores, whereas alpha-hydroxy acids are water-soluble and act mainly on the skin’s surface.

The skincare market is saturated with products boasting Vitamin C derivatives like ascorbyl palmitate or ascorbyl phosphate. However, L-ascorbic acid is the preferred form of Vitamin C in skincare because it is the most effective; other derivatives vary in stability and skin absorption, whereas L-ascorbic acid has the most established skin benefits.

Collagen synthesis in the skin decreases with sun exposure and aging, leading to wrinkles. Vitamin C is the only antioxidant proven to stimulate collagen synthesis and reduce fine lines and wrinkles. Redness or stinging may occur initially, but side effects usually subside as your skin adjusts.

Glycerin is a natural moisturizing agent commonly found in face creams and lip balms. It helps repair both dry and oily skin by locking in moisture, keeping skin hydrated overnight.

Hyaluronic acid, a glycosaminoglycan, is praised for its ability to reverse aging and is naturally present in young skin and connective tissues. With age, levels decline and are further impacted by smoking and a poor diet.

This form of Vitamin B3 helps keep the skin healthy and firm by supporting keratin production. For those with rosacea, it can reduce swelling and redness and help retain moisture when used in face masks.

Dimethicone is the second-most common moisturizer ingredient. It benefits dry skin, especially in winter, and can help soften scar tissue and improve skin softness.

Copper peptide is known for promoting skin regeneration by increasing the production of elastin and collagen. It also acts as an antioxidant and supports tissue repair, helping soften, smooth, and firm the skin.