Glossary
Water-soluble acids found in nature or synthesized in a laboratory. The most common AHAs used in the cosmetics industry are glycolic acid, lactic acid, citric acid, malic acid and tartaric acid. AHAs work on skin's surface to remove dead skin cells and reveal brighter, smoother + softer skin. Over time, they also support healthy collagen production to minimize the appearance of fine lines.
AHAs can increase skin’s sensitivity to the sun and to the possibility of sunburn. Use a broad-spectrum sunscreen and limit sun exposure while using products with AHAs and for a week after ceasing usage.
Substances that neutralize free radicals before they can damage skin cells and structural proteins. Free radicals are unstable molecules generated by UV exposure, air pollution, cigarette smoke, and environmental stress. Left unchecked, they accelerate collagen degradation, disrupt cellular signaling, and contribute to uneven skin tone and visible signs of premature aging.
The skin has its own antioxidant defense systems, but these are routinely overwhelmed by the intensity and frequency of modern environmental exposure. Topically applied antioxidants help compensate for this deficit. Common antioxidants in skincare include vitamins C and E, vitamin A (retinol), niacinamide, and a range of plant-derived compounds.
ZO's ZOX12® complex encapsulates vitamins A, C, and E in a time-release system that delivers up to 12 continuous hours of free radical protection, including protection against infrared-A (IR-A) rays – a spectrum of damaging radiation that standard sunscreen does not address.
The pure acid form of vitamin C and one of the most extensively studied topical antioxidants in dermatology. Ascorbic acid serves two clinically distinct functions in the skin. As an antioxidant, it neutralizes free radicals generated by UV exposure and environmental pollution, reducing oxidative damage to skin cells and structural proteins including collagen. As a brightening agent, it interrupts the melanin synthesis pathway by inhibiting tyrosinase activity, visibly reducing the appearance of dark spots and supporting a more even skin tone over time.
Ascorbic acid is inherently unstable and oxidizes rapidly when exposed to light, air, or heat. Formulation quality is the defining variable in efficacy: properly stabilized, encapsulated, or pH-adjusted vitamin C preparations maintain their potency and penetrate the skin more effectively than those in basic aqueous solutions. Concentration, pH, and delivery architecture are the factors that separate clinically meaningful vitamin C formulations from those with limited functional effect.
Sourced from the seeds of the Psoralea corylifolia (also known as the babchi or babuchi plant), which has been widely used in Indian and Chinese medicine to treat a variety of diseases. It is a natural antioxidant and skin soother that amplifies brightening while improving skin’s resiliency against discoloration aggressors.
Also known as salicylic acid. Unlike AHAs, which are water-soluble and act primarily at the skin's surface, BHAs are oil-soluble, enabling them to penetrate through the sebum inside a pore rather than working only at the outermost layer. This makes BHAs particularly effective for blemish-prone and oily skin types, where they help dissolve accumulated sebum, exfoliate within the pore lining, and reduce the appearance of congestion, blackheads, and post-blemish marks. BHAs also have documented anti-inflammatory properties at the skin surface.
A sunscreen that protects against both UVA and UVB rays.
Chemical sunscreen filters absorb harmful ultra-violet rays released from the sun. These rays are converted into heat and harmlessly released from the body.
Eczema, or atopic dermatitis, is a common inflammatory skin condition that causes symptoms such as itchiness, redness, dryness, rashes, scaly patches and infections.
A skin softening + smoothing ingredient used in moisturizers and hydrators. Examples of emollients include shea butter, plant oils, capric/capric tricglyerides and petrolatum.
A system of six skin types, ranging from very fair (type 1) to very dark (type VI), that classifies skin on its ability to burn or tan with sun exposure.
An atom or group of atoms with an unpaired electron. Unstable and highly reactive, free radicals can damage cells and are believed to accelerate the progression of cancer and many diseases as well as contribute to signs of skin aging. Free radicals can be produced by sunlight, cigarette smoke, air pollution and stress.
Natural substances produced by cells that manage essential tasks like cellular proliferation, soothing redness and supporting collagen + elastin production. ZO's plant and enzymatically derived growth factor technology helps to reduce the appearance of fine lines and wrinkles + restore the look of facial volume.
Getting Skin Ready®, or GSR®, is the foundation of healthy skin. It is a simple system of cleansing, exfoliating and toning that prepares skin for Prevent + Correct products.
Commonly known as blue light. HEV is a form of light believed to cause long-term skin damage as significant as UVA and UVB combined. While there may be no immediate signs such as redness or swelling, repeated exposure over time can lead to premature aging and even cancer. Sources of HEV light are the sun, electronics and fluroescent lights indoors.
A skin-bleaching agent that inhibits the production of melanin. It is used for lightening melasma, freckles, age spots and other skin hyperpigmentation concerns.
At ZO, clinically proven functional hydrators are used in place of traditional moisturizers. Functional hydrators accelerate hydration from within, soothe reactivity + redness and increase skin’s tolerance to more aggressive products like high-potency retinoids.
On the contrary, traditional moisturizers often offer only temporary, surface hydration and can weaken skin barrier function long-term, creating moisturizer dependency.
Darkening of an area of skin caused by increased melanin production. Hyperpigmentation presents as dark spots or sun spots, brown patches and red-brown marks after blemishes.
Chronic inflammation that damages cells and tissues over time, causing signs of premature aging such as uneven skin tone, dehydration, dullness and pronounced fine lines and wrinkles.
Group of pigments produced by cells in the skin, known as melanocytes. It gives color to hair, skin and iris of the eyes. It also helps protect the skin from the harmful effects of ultraviolet light. Eumelanin produces dark brown to black pigment and pheomelanin produces yellow to red pigment.
Delivery system that provides a rapid, effective delivery of active ingredients such as high-potency retinol into the skin.
Also known as vitamin B3 and nicotinic acid, niacinamide is a highly effective ingredient for enhancing skin health and combating skin-aging factors. Niacinamide has been shown to increase ceramide and free fatty acid levels in skin, minimize water loss and boost microcirculation. It is also noted for its ability to brighten uneven skin tone, including post-blemish marks.
A delivery system that provides a slow, controlled delivery of an ingredient, such as high-potency retinol, to allow for a higher concentration while minimizing reactions.
An imbalance between free radicals and antioxidant defenses that can lead to premature signs of skin aging such as dryness, fine lines + wrinkles and uneven skin tone.
Short chains of amino acids that act as messengers in the skin, signaling cells to perform specific functions. Different peptide sequences target different outcomes. Signal peptides prompt fibroblasts to produce more collagen. Carrier peptides deliver trace minerals that support enzymatic activity. Neuropeptides modulate neuromuscular communication to help reduce the visible appearance of expression-driven wrinkles. Enzyme-inhibitor peptides slow the breakdown of collagen and elastin. Because peptides work at the level of cellular signaling rather than through surface action, they are compatible with a broad range of skin types and can be layered alongside actives such as retinol and vitamin C.
ZO's Peptide Facial Refining Concentrate contains four distinct peptides – Acetyl Octapeptide-3, Acetyl Hexapeptide-8, a Refining Peptide Complex, and a Volumizing Tripeptide – each with a specific, targeted mechanism, rather than the single-peptide approach common in standard retail formulations.
Potential hydrogen (pH). The pH scale ranges from 1 to 14, with lower numbers being more acidic and higher numbers being more alkaline. A healthy skin pH is slightly acidic -- about 4.5 to 5.5.
Extreme skin sensitivity or an unusual reactions when skin is overexposed to UV radiation from sunlight, tanning beds or other light sources.
Physical sunscreen filters sit on top of the skin, creating a physical barrier to reflects the sun's rays. The two physical, or mineral, sunscreen filters are zinc oxide and titanium dioxide.
Skin that has undergone a procedure in a physician office such as laser resurfacing, microneedling or an aggressive chemical peel.
A vitamin A derivative and one of the most clinically studied topical actives in dermatology. When applied to the skin, retinol undergoes enzymatic conversion – first to retinaldehyde, then to retinoic acid – the biologically active form that binds to nuclear receptors in skin cells and initiates cellular renewal. This process supports the keratinocyte maturation cycle, promotes epidermal renewal, stimulates collagen synthesis, helps even skin tone, and visibly improves the appearance of fine lines, wrinkles, and surface texture over time.
Retinol requires a delivery system that protects its stability and controls the release of active molecules into the skin. ZO uses oleosomes – plant-derived, biomimetic delivery vessels that provide controlled, sustained retinol release – alongside a micro emulsion system for rapid epidermal release. ZO's ZO-RDS™ platform encapsulates retinol within a biomimetic liposomal structure for targeted delivery at specific epidermal depths. The Deep Delivery System (DDS) directs retinol toward the basal layer of the epidermis to support cellular renewal and address the appearance of wrinkles, texture, and elasticity. The Corneum Delivery System (CDS) localizes retinol at the stratum corneum, supporting visible brightening at the skin surface with minimized irritation.
An oily secretion of the sebaceous gland. While naturally produced by the body, sebum is an inflammatory substance. It induces a significant immune response contributing to clogged pores, blemishes, rosacea, seborrheic dermatitis, post-inflammatory hyperpigmentation (PIH) and scarring.
Skin that has been weakened by external or internal factors, ranging from harsh products to indoor winter heat. At ZO®, we believe that "sensitive skin" is sensitized, weak skin that needs to be strenghened with the right products.
The outermost layer of the skin (the stratum corneum) and the lipid matrix that holds its structure together. The skin barrier performs two simultaneous functions: it prevents transepidermal water loss (TEWL), keeping the skin hydrated and resilient; and it acts as a selective shield against environmental irritants, pollutants, allergens, and microorganisms.
A healthy skin barrier is the prerequisite for effective skincare. Products applied to a compromised barrier penetrate less predictably, cause more irritation, and deliver less reliable results. At ZO, Skin Barrier Function is the first of the eight principles underlying every protocol. Supporting and restoring the barrier is not a supplementary step; it is the foundation on which all correction and protection depend.
The visible improvement of uneven skin tone through normalized cellular turnover and reduced melanin accumulation at the skin's surface. Skin brightening differs from skin lightening or whitening, which works specifically to inhibit the body's natural pigment production. Brightening accelerates the shedding of pigment-laden surface cells and supports a more consistent melanin distribution without suppressing pigment formation at the source.
Active ingredients commonly associated with brightening effects include retinol, vitamin C, niacinamide, glycolic acid, lactic acid, and tranexamic acid. Each addresses pigment visibility through a distinct mechanism, which is why physician-guided protocols – combining multiple actives in a sequenced system – consistently produce more comprehensive results than single-ingredient approaches.
All ZO® sunscreens contain ingredients that protect your skin against damage from 3 types of rays:
- 1. UVA + UVA rays
- 2. High-Energy Visible (HEV) blue light from the sun + electronics
- 3. Infrared-A rays
Ultraviolet rays responsible for causing visible signs of aging. Their longer wavelength, 320 to 400 nm, allows them to reach skin's deeper layer, damaging important structural components such as collagen, elastin and hyaluronic acid. UVA rays are able to penetrate cloud cover and glass as well.
UVB rays responsible for sunburns. These burning rays are most linked to the formation of skin cancer. Wavelength of UVB rays is 280–320 nm.
A ZO® Skin Health exclusive technology, ZCORE™ is a targeting firming complex that improves the visible appearance of skin sagging, including neck skin.
A ZO® Skin Health exclusive technology, ZO-RRS2® is a redness reducing plant stem cell complex that helps to powerfully neutralize aging free radicals while soothing visible redness.
A ZO® Skin Health exclusive technology, ZOX12® is an exclusive antioxidant complex that slowly releases vitamins A, C and E into skin to deliver 12 hours of free radical protection.
A ZO® Skin Health exclusive technology, ZPOLY™ is a plant-derived polysaccharide complex that minimizes signs of premature aging while infusing extended hydration + strengthening skin’s barrier.
A ZO® Skin Health exclusive technology, ZPRO® is a biomimetic sericin protein complex that minimizes the look of fine lines while enhancing skin plumpness + hydration from within.