Ingredients
Concise, evidence-aware explainers for the ingredients and interventions that matter most.
Adapalene
Adapalene is a synthetic retinoid that selectively binds to RAR-beta and RAR-gamma receptors. It is more photostable than tretinoin, causes less irritation, and is now available over-the-counter at 0.1% in many countries. Strong evidence for acne; moderate evidence for photoageing.
Alpha Arbutin
Alpha arbutin is a glycosylated form of hydroquinone that inhibits tyrosinase (the key enzyme in melanin production) without the irritation or safety concerns of hydroquinone. It has moderate evidence for reducing pigmentation and is well tolerated by sensitive skin.
Azelaic Acid
A dicarboxylic acid with anti-inflammatory, antibacterial, and pigmentation-reducing properties. Often underused despite solid evidence, especially for acne and melasma.
Benzoyl Peroxide
Benzoyl peroxide is the most effective OTC ingredient for killing Cutibacterium acnes bacteria. Unlike topical antibiotics, bacteria do not develop resistance to benzoyl peroxide — making it a cornerstone of long-term acne management.
Centella Asiatica (Cica)
Centella asiatica extract and its active compounds (madecassoside, asiaticoside, asiatic acid, madecassic acid) have moderate evidence for wound healing, barrier repair, and anti-inflammatory effects. It is one of the best-tolerated calming ingredients available.
Ceramides
Ceramides are lipid molecules that constitute approximately 50% of the skin barrier's intercellular lipid matrix. Topical ceramides help restore and maintain barrier integrity, reduce transepidermal water loss, and support the function of active ingredients.
Glycolic Acid
Glycolic acid is the smallest alpha hydroxy acid, allowing it to penetrate most effectively into the epidermis. It has strong evidence for improving skin texture, reducing fine lines, treating acne, and fading pigmentation at concentrations of 5–10% (OTC) or higher (professional peels).
Hyaluronic Acid
Hyaluronic acid (HA) is a glycosaminoglycan naturally present in skin that can hold up to 1,000 times its weight in water. Topical HA draws moisture into the epidermis, improving hydration, plumpness, and fine line appearance — but it needs to be sealed in with an occlusive or moisturiser.
Lactic Acid
Lactic acid is an AHA with a larger molecular size than glycolic acid, resulting in slower penetration and less irritation. It has the added benefit of being a natural moisturising factor (NMF) component, providing exfoliation and hydration in one step.
Mandelic Acid
Mandelic acid is the largest common AHA (molecular weight 152 Da), giving it the slowest penetration and lowest irritation potential. It has evidence for acne, pigmentation, and texture with reduced risk of post-inflammatory hyperpigmentation — making it particularly valuable for Fitzpatrick skin types IV–VI.
Niacinamide
A form of vitamin B3 often used for oil control, pore appearance, barrier support, and mild pigmentation improvement. Well-tolerated by most skin types.
Peptides
Peptides are short amino acid chains that act as cell-signalling molecules. In skincare, they are used to stimulate collagen production, support barrier repair, and reduce fine line appearance. Evidence is moderate for specific peptides but marketing often overstates their effects.
Retinol
An over-the-counter retinoid that promotes cell turnover and may support collagen production. Strong evidence for wrinkles and texture, but requires patience and careful introduction.
Salicylic Acid (BHA)
Salicylic acid is a lipophilic (oil-soluble) exfoliant that can penetrate into pores to dissolve sebum plugs and dead cell buildup. It has strong evidence for comedonal acne (blackheads, whiteheads) and moderate evidence for inflammatory acne.
Squalane
Squalane is the hydrogenated (stable) form of squalene, a lipid naturally produced by skin. It is an excellent lightweight emollient that reinforces the skin barrier, reduces transepidermal water loss, and is non-comedogenic despite being an oil. Well tolerated by virtually all skin types.
Sunscreen (SPF)
Broad-spectrum sunscreen (SPF 30–50+) is the most evidence-backed intervention for preventing photoageing, hyperpigmentation, and skin cancer. It protects the results of every other active in your routine. There is no close second.
Tranexamic Acid
Tranexamic acid inhibits melanin production by blocking the plasminogen-to-plasmin conversion that activates melanocytes. It has growing RCT evidence for melasma treatment (both oral and topical) and is well tolerated with minimal irritation.
Tretinoin
Tretinoin (all-trans retinoic acid) is the most studied topical anti-ageing ingredient in dermatology. It is the active form of vitamin A — no conversion required — and has strong evidence for reducing wrinkles, improving skin texture, treating acne, and reversing photoageing.
Vitamin C (L-Ascorbic Acid)
L-ascorbic acid is the most studied form of topical vitamin C. It may support collagen synthesis, brighten skin tone, and provide additional photoprotection when used under sunscreen.
Vitamin E (Tocopherol)
Topical vitamin E (tocopherol) is a fat-soluble antioxidant that protects cell membrane lipids from oxidative damage. Its most valuable role is as a synergist — it significantly enhances the photoprotective efficacy of vitamin C and helps stabilise formulations.