Science-backed information on skincare ingredients starting with the letter G
Jump to ingredient:
The Gold Standard Humectant
Humectant
Water Soluble
All Skin Types, Dry Skin
Moisturizers, Serums, Cleansers
Highly Proven
Plant-Based / Synthetic
Glycerin (also spelled glycerine) is one of the most effective and well-researched humectants in skincare. It attracts water from the air and from deeper layers of the skin, drawing moisture to the outer skin barrier to keep it hydrated throughout the day. Unlike some humectants that can feel sticky or draw moisture in dry environments, glycerin is prized for its lightweight, smooth feel and ability to improve skin softness and elasticity almost immediately upon application.
Attracts and retains moisture in the skin
Improves skin softness and texture
Helps strengthen the skin barrier
Suitable for all skin types, including sensitive skin
Enhances penetration of other ingredients
Non-comedogenic and fragrance-free
Extensive clinical research confirms glycerin's moisturizing efficacy. Studies show that glycerin at 5-10% concentrations significantly improves skin hydration within 30 minutes of application. Research published in Skin Pharmacology and Physiology demonstrates that glycerin helps repair damaged skin barriers and increases skin elasticity. Its safety profile is excellent—it's even used in pharmaceutical formulations as a humectant and penetration enhancer.
Glycerin is typically used at 2-10% in skincare formulations, though it can be used higher (up to 30%) in leave-on products. It pairs exceptionally well with occlusive ingredients like ceramides and fatty acids, which help lock in the moisture glycerin draws to the skin. Look for glycerin high in the ingredient list—it's one of the few ingredients where position matters less, as it's effective even at lower percentages.
Did You Know?
Glycerin is actually a byproduct of soap making! It's naturally produced when fats are saponified (converted to soap), which is why it's sometimes called "glycerine" in personal care products.
Glycerin is derived from plant sources (vegetable oils like coconut, palm, or soybean) or can be synthesized. Plant-based glycerin is renewable and biodegradable. It's vegan, cruelty-free, and has minimal environmental impact during production. The synthetic version is identical at the molecular level to plant-derived glycerin.
The Potent Antioxidant Powerhouse
Polyphenol Antioxidant
Water Soluble
Anti-Aging, Acne, Redness
Serums, Moisturizers, Toners
Clinically Proven
Plant Extract (Camellia sinensis)
Green tea extract is rich in polyphenols, particularly catechins like EGCG (epigallocatechin gallate), which are powerful antioxidants that protect skin from free radical damage caused by UV radiation, pollution, and stress. These compounds help neutralize oxidative stress, reduce inflammation, and may even inhibit enzymes that break down collagen. Beyond its antioxidant benefits, green tea has natural anti-inflammatory and sebum-regulating properties, making it beneficial for acne-prone and sensitive skin.
Protects against environmental damage
Reduces redness and inflammation
Helps control excess oil and acne
May help preserve collagen and elastin
Soothes sensitive and irritated skin
Provides some UV protection benefits
Clinical studies demonstrate green tea's potent antioxidant activity—it outperforms many other antioxidants in its ability to neutralize free radicals. Research shows 2-5% green tea extract significantly reduces UV-induced damage and improves skin elasticity. Studies in Photodermatology, Photoimmunology & Photomedicine confirm its anti-inflammatory effects for conditions like rosacea and acne.
Green tea extract is most effective at 2-5% concentration. It's water-soluble and works well in toners, serums, and lightweight moisturizers. The key active EGCG is somewhat unstable when exposed to light and air, so products in opaque, air-tight packaging maintain potency better. Green tea pairs nicely with other antioxidants like vitamin C and resveratrol for enhanced protection.
Did You Know?
It takes about 30 cups of brewed green tea to equal the antioxidant content found in a single gram of high-quality green tea extract—that's the power of concentrated extracts!
Green tea is harvested from the leaves of Camellia sinensis plants, primarily grown in China, Japan, and Korea. Sustainable farming practices (organic, fair trade) ensure minimal environmental impact. The extract is produced through water or alcohol extraction of dried leaves. Look for certifications like USDA Organic to ensure responsible sourcing.
The Gold Standard Alpha Hydroxy Acid
Alpha Hydroxy Acid (AHA)
Water Soluble
Exfoliation, Hyperpigmentation
Peels, Toners, Serums
Highly Proven
Sugarcane / Synthetic
Glycolic acid is the smallest molecular weight AHA, which means it penetrates skin more deeply than other AHAs like lactic or mandelic acid. It works by breaking down the "glue" that holds dead skin cells together on the surface, revealing fresher, brighter skin underneath. This exfoliation stimulates cell turnover, helps fade dark spots, reduces fine lines, and improves skin texture. Because it also boosts collagen production, it's considered one of the most effective anti-aging ingredients in skincare.
Provides deep chemical exfoliation
Fades hyperpigmentation and dark spots
Reduces fine lines and wrinkles
Improves skin texture and tone
Stimulates collagen production
Helps unclog pores and reduce acne
Extensive clinical research supports glycolic acid's efficacy. Studies show 10% glycolic acid applied daily improves fine wrinkles, skin texture, and hyperpigmentation within 12 weeks. Research in Journal of Cosmetic Dermatology demonstrates significant collagen and elastin fiber increases after 3 months of use. It's FDA-approved for professional chemical peels and remains the benchmark against which other exfoliants are measured.
Glycolic acid works best at pH 3.5-4.0—the lower the pH, the more potent but also more irritating. For home use, 5-10% is typical; professional peels can reach 20-70%. Start with lower concentrations (5%) if you're new to acids. It increases sun sensitivity, so always use SPF 30+ the next day. Pairs well with soothing ingredients like niacinamide or allantoin to minimize irritation.
Did You Know?
Glycolic acid was originally used by dermatologists in professional peels before being adapted for at-home use. Its "sweet spot" for home use is around 10%—strong enough to work, gentle enough for regular use with proper sun protection.
Glycolic acid is naturally found in sugarcane, sugar beets, and some fruits. Commercial production typically uses sugarcane-derived glycolic acid through a process involving oxidation of crude sugar. The synthetic version is identical in molecular structure. Both are sustainable and renewable. Look for products specifying natural-origin glycolic acid if sourcing matters to you.
Advanced Retinoid with Less Irritation
Retinoid (Hydroxypinacolone Retinoate)
Oil Soluble
Anti-Aging, Sensitive Skin
Serums, Creams, Oils
Clinically Proven
Synthetic (Proprietary)
Granactive® Retinol (hydroxypinacolone retinoate) is an advanced retinoid that delivers visible anti-aging benefits with significantly less irritation than traditional retinol. Unlike retinol, which must convert to retinoic acid in the skin (a process that can cause redness and flaking), Granactive® Retinol binds directly to retinoid receptors in the skin, providing similar benefits without the harsh side effects. It's considered a "next-generation" retinoid ideal for those who want retinoid benefits but can't tolerate traditional retinol products.
Reduces fine lines and wrinkles
Improves skin texture and tone
Minimizes pore appearance
Brightens and evens skin tone
Much less irritating than retinol
Suitable for sensitive skin
Clinical trials show Granactive® Retinol at 0.2-0.5% delivers comparable anti-aging results to 0.5-1% retinol with dramatically reduced irritation. Studies demonstrate significant improvements in wrinkle depth, skin elasticity, and pigmentation after 4-8 weeks of use. The patented delivery system allows the retinoid to work without conversion, making it ideal for those new to retinoids or with sensitive skin.
Granactive® Retinol is typically used at 0.2-0.5% in formulations (compared to 1-2% for traditional retinol). It's oil-soluble, making it ideal for serums and facial oils. The formulation is stable and doesn't oxidize as quickly as traditional retinol. It can be used morning or evening, though nighttime use is still recommended for optimal results. Pairs well with peptides, hyaluronic acid, and calming ingredients.
Did You Know?
Granactive® Retinol is a trademarked ingredient by The Ordinary's parent company (DECIEM). The term refers specifically to Hydroxypinacolone Retinoate (HPR), a ester of retinoic acid that doesn't require conversion in the skin.
Granactive® Retinol (hydroxypinacolone retinoate) is a synthetically produced retinoid created in laboratory settings. It's a proprietary ingredient developed by DECIEM (parent company of The Ordinary). The manufacturing process is efficient and sustainable, using controlled synthesis rather than natural extraction. The ingredient is synthetic but identical to what's naturally occurring in the skin.