Glossary

AHA (Alpha Hydroxy Acid): Water-soluble exfoliating acids including glycolic, lactic, and mandelic acid. Work on the surface of the skin.

Ablative laser: A laser that removes the outer layers of skin to allow it to heal back smoother. CO2 and erbium lasers are the most common ablative types.

Adapalene: An over-the-counter retinoid (sold as Differin) effective for acne and overall skin quality. About $15 at drugstores.

Antioxidant: A substance that neutralizes free radicals. Vitamin C, vitamin E, and ferulic acid are common skincare antioxidants.

Azelaic Acid: A multi-purpose active ingredient effective for rosacea, melasma, acne, and post-inflammatory hyperpigmentation. Safe during pregnancy.

BHA (Beta Hydroxy Acid): Salicylic acid. An oil-soluble acid that penetrates pores and is particularly useful for acne and oily skin.

Biostimulator: A substance injected into the skin that stimulates the body's own collagen production over time. Sculptra and Radiesse are examples.

Botulinum Toxin (Botox, Dysport, Xeomin, Daxxify, Jeuveau): A neurotoxin that temporarily blocks nerve signals to specific muscles, preventing them from contracting.

Ceramides: Lipid molecules that are part of the skin barrier. Topical ceramides help support and repair the barrier.

Collagen: A structural protein in the skin that provides firmness and elasticity. Production declines with age.

Dermis: The deeper layer of skin beneath the epidermis, containing collagen, elastin, blood vessels, and other structures.

Epidermis: The outer layer of skin, which includes the protective barrier and is where most skincare products primarily act.

Filler (Dermal Filler): Injectable substances used to add volume, soften lines, or restore facial structure. Most modern fillers are hyaluronic acid-based.

Fitzpatrick Scale: A classification system for skin types based on their response to UV exposure, ranging from Type I (always burns) to Type VI (never burns).

Fractional Laser: A laser that treats columns of skin while leaving surrounding tissue intact, allowing for faster healing and effective skin resurfacing.

HRT (Hormone Replacement Therapy): Treatment with estrogen, often combined with progesterone, to address symptoms of menopause.

Hyaluronic Acid: A naturally occurring substance in the skin that holds water. Used topically as a humectant and injectably as filler.

Hyaluronidase: An enzyme that dissolves hyaluronic acid filler. Essential for managing complications.

IPL (Intense Pulsed Light): A light-based treatment that addresses pigmentation, redness, and overall skin tone.

Melasma: Patches of darker pigmentation, typically on the face, often hormonally driven.

Microneedling: A procedure that uses fine needles to create controlled micro-injuries in the skin, stimulating collagen production.

Niacinamide: Vitamin B3. A multi-purpose active that supports the skin barrier, regulates oil, reduces inflammation, and helps with pigmentation.

Peptide: A short chain of amino acids that signals specific cellular activity in the skin. Different peptides have different effects.

Photoaging: Skin aging caused by sun exposure. Accounts for the majority of visible facial aging.

Post-Inflammatory Hyperpigmentation (PIH): Darkening of the skin following inflammation, such as acne or injury.

Retinoid: Any vitamin A derivative used in skincare. Includes retinol, retinaldehyde, adapalene, and tretinoin.

RF (Radiofrequency): Energy delivered into the skin to heat deeper tissues and stimulate collagen production.

SPF (Sun Protection Factor): A measure of a sunscreen's ability to protect against UVB radiation. SPF 30 blocks about 97% of UVB.

Tranexamic Acid: An active ingredient that interrupts melanin production. Used topically or orally for pigmentation issues, especially melasma.

Tretinoin (Retin-A): A prescription-strength retinoid. The most potent commonly available form.

UVA/UVB: The two main types of ultraviolet radiation that reach the skin. UVA contributes mainly to aging; UVB causes sunburn and skin cancer.