What is the difference between AHA and BHA?

AHAs (alpha-hydroxy acids — glycolic, lactic, mandelic acid) are water-soluble exfoliants that work on the surface of the skin, dissolving the bonds between dead skin cells. They are best for dull, dry, or sun-damaged skin. BHAs (beta-hydroxy acids — primarily salicylic acid) are oil-soluble, meaning they penetrate into pores and dissolve sebum congestion from within. BHAs are preferred for oily, acne-prone, and congested skin. Both reduce textured skin, fade surface pigmentation, and improve overall complexion clarity over time.

Is hyaluronic acid a moisturiser?

Hyaluronic acid (HA) is a humectant — it attracts and binds water from the environment or deeper skin layers. Applied to damp skin in a humid environment (like Nepal's monsoon), it draws moisture into the skin surface. In dry environments or if applied to dry skin, it can draw moisture from the dermis upward and then evaporate, slightly worsening dryness. Always apply hyaluronic acid serum to damp skin, then seal with a moisturiser containing occlusives (like ceramides) to prevent moisture evaporation.

Can I use retinol and vitamin C together?

It is generally recommended to separate these two. Vitamin C (ascorbic acid) is most stable and effective in an acidic environment (pH 2.5–3.5), while retinol degrades at low pH and can be irritating when combined with other actives. The standard recommendation is vitamin C in the morning (it also provides some antioxidant protection against UV damage) and retinol at night. However, some stabilised forms of vitamin C (like sodium ascorbyl phosphate) and encapsulated retinol can be formulated to work together.

What does 'non-comedogenic' mean?

Non-comedogenic means a product has been formulated to not clog pores (comedones are blocked follicles — blackheads and whiteheads). Non-comedogenic products omit or minimise highly comedogenic ingredients (like coconut oil, lanolin, certain silicones at high concentrations). However, 'non-comedogenic' is not a regulated term — there is no standardised test required to use this label. It is a useful indicator but not a guarantee for acne-prone skin.

Skincare Ingredient Glossary A–Z | What Every Ingredient Does

How to Use This Glossary

This reference page defines the active ingredients, functional ingredients, and skin-concern terms you will encounter in skincare product labels and guides. Each entry covers: what it is, what it does, who benefits, and common misconceptions.

Use Ctrl+F / Cmd+F to jump directly to an ingredient by name.

A

AHA (Alpha-Hydroxy Acids)

A family of water-soluble chemical exfoliants. Common AHAs include glycolic acid, lactic acid, and mandelic acid.

What they do: Dissolve the bonds between dead skin cells on the surface, accelerating cell turnover. Regular use fades surface pigmentation, smooths rough texture, and improves radiance.

Best for: Dull skin, dry skin, surface pigmentation, sun-damaged skin.

Caution: Increase photosensitivity — always use SPF when incorporating AHAs.

Allantoin

A soothing compound derived from comfrey root (or synthesised). Reduces irritation, promotes skin healing, and is included in barrier-repair and post-procedure formulas.

Antioxidants

A broad class of ingredients that neutralise free radicals (unstable molecules generated by UV, pollution, and metabolic processes that damage skin cells and proteins). Examples: Vitamin C, Vitamin E, niacinamide, coenzyme Q10, green tea polyphenols. See individual entries.

B

BHA (Beta-Hydroxy Acids)

Oil-soluble chemical exfoliants, primarily salicylic acid. Penetrate inside pores to dissolve sebum congestion.

What they do: Exfoliate inside follicles, reduce blackheads and whiteheads, have anti-inflammatory and mild antibacterial properties.

Best for: Oily skin, acne-prone skin, congested pores, sebaceous filaments.

Benzoyl Peroxide

An antimicrobial agent that releases free oxygen inside follicles, killing P. acnes bacteria. Available as a leave-on treatment or wash-off cleanser.

Best for: Inflammatory acne (papules, pustules). Particularly effective for antibiotic-resistant P. acnes.

Caution: Bleaches fabrics. Can be irritating at higher concentrations — start with 2.5%.

C

Ceramides

Lipid molecules that are naturally present in the skin's outer layer (stratum corneum), making up approximately 50% of the skin barrier. They keep moisture in and irritants/bacteria out.

What they do in skincare: Replenish depleted barrier lipids, improve skin barrier function, reduce transepidermal water loss.

Best for: Dry skin, eczema, sensitive skin, post-procedure skin, barrier-compromised skin.

Ceraedge Cream contains ceramides for targeted barrier repair.

Centella Asiatica (CICA)

Extract from the herb Centella asiatica (also called gotu kola). Contains asiaticoside, madecassoside, and asiatic acid — compounds with anti-inflammatory and wound-healing properties.

Best for: Sensitive, irritated, or redness-prone skin. Post-procedure healing. Used in Korean skincare extensively.

Coenzyme Q10 (Ubiquinone)

An antioxidant that occurs naturally in skin cells and declines with age. Used in anti-aging formulations.

D

Dimethicone

A silicone-derived ingredient used as an emollient and skin barrier protectant. Very low irritation potential. Provides a smooth, non-greasy skin feel. Used in barrier creams and moisturisers.

E

Emollients

Ingredients that soften and smooth skin by filling gaps between skin cells. Examples: glycerine, petrolatum, squalane, fatty acids. Distinct from occlusives (which form a physical barrier to prevent moisture loss) and humectants (which attract water).

F

Ferulic Acid

A plant-derived antioxidant, most commonly used to stabilise and enhance the efficacy of vitamin C serums. The classic combination of vitamin C 15% + vitamin E 1% + ferulic acid 0.5% has significant photostability data.

G

Glycerin (Glycerol)

One of the most widely used humectants in skincare. Attracts water from the environment and deeper skin layers to the skin surface. Effective, inexpensive, and very well tolerated.

Glycolic Acid

The smallest AHA, derived from sugarcane. Due to its small molecular size, it penetrates most deeply of the AHAs, making it the most potent and effective but also most likely to cause irritation. Used in chemical peels and toners.

H

Hyaluronic Acid (HA)

A naturally occurring glycosaminoglycan that holds water in the extracellular matrix of skin. A single molecule can bind up to 1,000 times its own weight in water.

In skincare: Used as a humectant in serums and moisturisers. Apply to damp skin and seal with an occlusive moisturiser for best results.

Best for: All skin types, particularly dehydrated or dry skin.

See: Hyaluronic Acid Serum Benefits

I

Isotretinoin

A prescription-only oral retinoid (vitamin A derivative) used for severe or treatment-resistant acne. Not available OTC — must be prescribed and monitored by a dermatologist due to significant side effects including teratogenicity. Not to be confused with topical retinol (see Retinol entry below).

J

Jojoba Oil

A liquid wax (technically a wax ester, not an oil) derived from jojoba seeds. Has a similar chemical structure to human sebum. Non-comedogenic (comedogenicity score 2), making it suitable for most skin types as a facial oil or carrier oil.

K

Kaolin

A white clay used in face masks and absorbing powders. Absorbs excess sebum without stripping. Suitable for oily and combination skin types.

Kojic Acid

A natural skin brightener derived from fungi, used as a tyrosinase inhibitor to reduce melanin production. Used in brightening serums and hyperpigmentation treatments.

L

Lactic Acid

A mild AHA derived from milk fermentation. Gentler than glycolic acid due to its larger molecular size. Also a natural moisturising factor component.

Best for: Dry, sensitive, or eczema-prone skin that cannot tolerate glycolic acid.

M

Mandelic Acid

An AHA derived from bitter almonds. Has the largest molecular size of common AHAs, making it the gentlest, with slowest penetration. Also has mild antibacterial properties.

Best for: Sensitive skin, darker skin tones (lower risk of post-exfoliation PIH than glycolic acid), acne-prone skin.

Mineral Sunscreen Actives (Zinc Oxide, Titanium Dioxide)

Physical UV filters that sit on the skin surface and reflect/scatter UV radiation. No systemic absorption (unlike chemical filters). Do not cause hormonal disruption. Suitable for sensitive skin and during pregnancy.

UVedge Soft Mineral SPF-50 Gel uses zinc oxide as its primary UV filter.

N

Niacinamide (Vitamin B3)

One of the most multi-functional and well-researched skincare actives. Mechanisms include:

Inhibits melanosome transfer from melanocytes to keratinocytes (brightens hyperpigmentation)
Strengthens the skin barrier by increasing ceramide production
Reduces sebum overproduction
Has anti-inflammatory properties (reduces acne redness)
Stimulates collagen production

Best for: Oily/acne-prone skin, pigmentation, enlarged pores, all skin types for general maintenance.

Niafine Serum delivers concentrated niacinamide.

See: What Is Niacinamide?

O

Occlusives

Ingredients that form a physical barrier on the skin surface to reduce transepidermal water loss (TEWL). Examples: petrolatum (most effective), beeswax, dimethicone, squalane. Used in the final layer of a skincare routine to seal in moisture and humectants.

P

Panthenol (Vitamin B5)

A provitamin of pantothenic acid. Has excellent skin penetration, converting to pantothenic acid in the skin. Properties: humectant (attracts moisture), emollient (softens), anti-inflammatory, wound-healing. Very well tolerated, suitable for sensitive and irritated skin.

Peptides

Short chains of amino acids (the building blocks of proteins). In skincare, peptides are used to:

Signal skin cells to produce more collagen (signal peptides)
Inhibit muscle contraction (neurotransmitter-inhibiting peptides — claimed to reduce expression lines)
Carry and deliver minerals to skin cells (carrier peptides)

Evidence is generally limited for OTC peptide products; prescription tretinoin and clinical procedures have stronger evidence for anti-aging.

R

Retinol

The OTC form of vitamin A. Converts in skin to retinoic acid (the active form), which binds nuclear receptors to:

Increase cell turnover (accelerates shedding of aged skin cells)
Stimulate collagen production
Reduce fine lines and improve texture
Treat acne by reducing follicular keratinisation

Caution: Causes initial irritation (retinisation — dryness, redness, peeling). Start with low concentration (0.025–0.1%) every third night. Do not use during pregnancy.

See: Retinol for Beginners

Retinoids

The broader class of vitamin A derivatives including retinol (OTC), retinaldehyde (OTC, more potent), adapalene (OTC Rx transition), and tretinoin/isotretinoin (prescription only).

S

Salicylic Acid

The primary BHA. Oil-soluble, penetrates pores to dissolve sebum congestion. Has anti-inflammatory and mild antibacterial properties (disrupts bacterial cell membranes). Available in cleansers, toners, spot treatments, and serums at 0.5–2%.

Best for: Acne-prone skin, oily skin, blackheads and whiteheads, sebaceous filaments.

Squalane

A stable, hydrogenated form of squalene (naturally produced by skin). A lightweight, non-greasy emollient. Non-comedogenic, suitable for most skin types including oily.

SPF (Sun Protection Factor)

A measurement of how much UVB radiation a sunscreen product filters. SPF 30 allows 1/30th of UVB to penetrate (filters ~97%). SPF 50 filters ~98%. Note: SPF only measures UVB protection — look for "broad-spectrum" designation to ensure UVA coverage as well.

See: Best Sunscreen in Nepal

T

Tranexamic Acid

A synthetic amino acid (lysine derivative) originally used systemically to reduce bleeding. In topical skincare, it inhibits the UV-induced activation of plasminogen in keratinocytes, which reduces the paracrine signals that stimulate melanocytes. Emerging first-line treatment for melasma and hyperpigmentation.

Lumiedge TX Cream delivers tranexamic acid for melasma treatment.

See: Melasma Treatment Nepal

V

Vitamin C (L-Ascorbic Acid)

The most evidence-backed topical antioxidant. Mechanism in skin:

Neutralises free radicals from UV exposure
Inhibits tyrosinase (reduces melanin synthesis)
Stimulates collagen production
Has mild photo-protective effect (additive to SPF, not a replacement)

Stable in acidic pH (2.5–3.5) — can be irritating at effective concentrations (10–20%). Derivatives like sodium ascorbyl phosphate and ascorbyl glucoside are more stable but require conversion to active form.

See: How to Use Vitamin C in Skincare

Vitamin E (Tocopherol)

A fat-soluble antioxidant that also acts as an emollient. Works synergistically with vitamin C and ferulic acid. Restores photodamaged lipids in the skin barrier.

Z

Zinc Oxide

A physical UV filter providing both UVA and UVB protection. Also has anti-inflammatory properties, making it useful in barrier creams for eczema and nappy rash and in mineral sunscreens (UVedge Soft Mineral SPF-50 Gel).

Summary: The Core Ingredients to Know

Ingredient	Primary Benefit	Best For
Niacinamide	Brightening, barrier, sebum	All skin types
Retinol	Anti-aging, acne	Ageing, textured skin
Hyaluronic Acid	Hydration	Dehydrated skin
Ceramides	Barrier repair	Dry, eczema-prone
Salicylic Acid	Pore clearing, acne	Oily, acne-prone
Tranexamic Acid	Melasma, hyperpigmentation	Pigmentation
Vitamin C	Brightening, antioxidant	Dull, pigmented skin
Zinc Oxide	UV protection	All skin types
Glycerin	Hydration	All skin types

Start building your routine at Skincare Routine for Beginners.

Skincare Ingredient Glossary: A–Z Guide for Nepal