Skincare, without the hype.

Vitamin A derivatives that bind nuclear retinoic-acid receptors to normalize follicular keratinization and speed epidermal turnover, while stimulating fibroblast collagen synthesis. They treat acne, soften fine lines, and fade hyperpigmentation.

Concentration

0.25–1% (retinol); 0.1% (adapalene, OTC)

Timeline

8–12 weeks (up to 6 months for anti-aging)

Pairs with

Niacinamide, Hyaluronic Acid, Sunscreen

Avoid with

Benzoyl Peroxide, Glycolic Acid, Salicylic Acid

A potent antioxidant that neutralizes UV-generated free radicals and acts as an essential cofactor for the enzymes that synthesize and stabilize collagen; it also inhibits tyrosinase to reduce melanin. The result is brighter, firmer, more even skin.

Concentration

10–20% (pH < 3.5)

Timeline

8–12 weeks

Pairs with

Vitamin E, Ferulic Acid, Sunscreen, Niacinamide

Avoid with

No known conflicts

A form of vitamin B3 that boosts ceramide synthesis to strengthen the barrier and reduce water loss, while calming inflammation, regulating sebum, and blocking melanosome transfer to keratinocytes. It reduces redness, blemishes, and uneven tone.

Concentration

2–5%

Timeline

4–8 weeks

Pairs with

Hyaluronic Acid, Retinol, Vitamin C, Zinc

Avoid with

No known conflicts

A dicarboxylic acid that is antibacterial against C. acnes, scavenges reactive oxygen species to calm inflammation, normalizes keratinization, and competitively inhibits tyrosinase. It treats acne, rosacea-related redness, and dark spots.

Concentration

10% (OTC); 15–20% (Rx)

Timeline

8–16 weeks

Pairs with

Niacinamide, Retinol, Sunscreen

Avoid with

No known conflicts

An oxidizing agent that concentrates in the follicle and releases reactive oxygen species which kill C. acnes without inducing bacterial resistance, with mild comedolytic and keratolytic action. It treats inflammatory acne.

Concentration

2.5–10%

Timeline

4–8 weeks

Pairs with

Adapalene, Salicylic Acid, Niacinamide

Avoid with

Tretinoin, Retinol, Vitamin C (L-Ascorbic Acid)

A lipophilic beta-hydroxy acid that penetrates sebum-filled pores and dissolves the desmosomal bonds between corneocytes, exfoliating inside the follicle, with added anti-inflammatory action. It clears blackheads and treats acne in oily skin.

Concentration

0.5–2%

Timeline

4–8 weeks

Pairs with

Niacinamide, Benzoyl Peroxide, Hyaluronic Acid

Avoid with

Retinoids, Glycolic Acid

The smallest alpha-hydroxy acid, it weakens corneocyte cohesion to promote surface exfoliation and, with continued use, stimulates collagen and glycosaminoglycan synthesis. It improves texture, dullness, and dark spots — but increases sun sensitivity.

Concentration

5–10% (OTC)

Timeline

4–12 weeks

Pairs with

Hyaluronic Acid, Niacinamide, Sunscreen

Avoid with

Retinoids, Salicylic Acid

An alpha-hydroxy acid that exfoliates by loosening corneocyte adhesion while also acting as a natural moisturizing factor, making it gentler and more hydrating than glycolic acid. It smooths texture and brightens dry or sensitive skin.

Concentration

5–12%

Timeline

4–12 weeks

Pairs with

Hyaluronic Acid, Niacinamide, Sunscreen

Avoid with

Retinoids

A glycosaminoglycan humectant that binds large amounts of water; high-molecular-weight forms sit on the surface as a hydrating film, low-molecular-weight forms penetrate the stratum corneum. Because it is a humectant, in dry air it can pull water from deeper skin — so apply to damp skin and seal it.

Concentration

0.1–2%

Timeline

Immediate (hydration within ~1 hour)

Pairs with

Glycerin, Ceramides, Niacinamide, Peptides

Avoid with

No known conflicts

A small humectant that attracts and holds water in the stratum corneum, delivered into the epidermis partly via aquaporin-3. It raises hydration, improves plasticity and desquamation, and supports barrier recovery — one of the best-evidenced moisturizing agents.

Concentration

~2–10%

Timeline

Immediate (sustained through 24 hours)

Pairs with

Hyaluronic Acid, Ceramides, Niacinamide

Avoid with

No known conflicts

A microbial peptide biopolymer with abundant carboxyl groups that binds and holds large amounts of water, forming a smooth self-moisturizing film that lowers water loss. It can also upregulate hyaluronic-acid synthase and aquaporin-3, and reportedly holds more water than hyaluronic acid.

Concentration

0.1–1%

Timeline

Immediate surface hydration and plumping

Pairs with

Hyaluronic Acid, Glycerin, Niacinamide, Ceramides

Avoid with

No known conflicts

Sphingolipids that make up roughly 50% of stratum corneum lipids by mass (with ~25% cholesterol and ~15% free fatty acids) and organize into the lamellar bilayers that form the permeability barrier. Reinforcing them lowers water loss; deficiencies are a hallmark of atopic dermatitis.

Concentration

—

Timeline

Gradual (barrier improvement over ~2–4 weeks)

Pairs with

Cholesterol, Fatty Acids, Hyaluronic Acid, Glycerin, Niacinamide

Avoid with

No known conflicts

One of the three key stratum corneum lipids (about 25% of them), required to organize the lamellar bilayers of the barrier. Applied in optimized, cholesterol-dominant ratios it accelerates barrier recovery, especially in aged skin.

Concentration

~2–4% (in balanced blends)

Timeline

Barrier recovery within hours experimentally; visible over 2–4 weeks

Pairs with

Ceramides, Free Fatty Acids, Niacinamide, Squalane

Avoid with

No known conflicts

A fully saturated emollient made by hydrogenating squalene (a natural sebum lipid), which makes it highly stable and non-comedogenic. It softens skin, reduces water loss, and penetrates efficiently without an oily feel.

Concentration

—

Timeline

Immediate softening; sustained hydration within days

Pairs with

Retinol, Vitamin C, Niacinamide, Ceramides, Cholesterol

Avoid with

No known conflicts

The stable analog of vitamin B5, converted in skin to pantothenic acid. As a humectant it improves hydration and lowers water loss, while soothing irritation, reducing erythema, and supporting barrier repair and re-epithelialization.

Concentration

1–5%

Timeline

Soothing within days; barrier repair over ~2–4 weeks

Pairs with

Niacinamide, Hyaluronic Acid, Ceramides, Allantoin, Squalane

Avoid with

No known conflicts

A naturally derived polysaccharide whose structure forms a moisture-retaining film, while also acting as an immunomodulator (via Dectin-1) that regulates inflammatory mediators and stimulates keratinocyte repair. It combines humectant, soothing, and wound-healing activity.

Concentration

0.1–0.5%

Timeline

Immediate hydration; calming and repair over days to weeks

Pairs with

Hyaluronic Acid, Niacinamide, Ceramides, Panthenol

Avoid with

No known conflicts

A urea derivative that is keratolytic — helping shed excess keratin and smooth skin — while soothing irritation and promoting wound healing by stimulating cell proliferation and extracellular-matrix synthesis.

Concentration

0.1–2%

Timeline

Soothing within days; smoother texture over days to weeks

Pairs with

Niacinamide, Panthenol, Hyaluronic Acid, Retinoids

Avoid with

No known conflicts

A sesquiterpene alcohol from German chamomile that soothes skin by suppressing inflammatory mediators (iNOS, COX-2, TNF-α) and inhibiting NF-κB. It has good dermal absorption with low toxicity and no sensitization — well suited to calming reactive skin.

Concentration

0.1–1%

Timeline

Reduced redness and irritation within days

Pairs with

Niacinamide, Vitamin C, Retinoids, Allantoin

Avoid with

No known conflicts

A plant-derived meroterpene that acts as a functional analog of retinol, reducing wrinkles and hyperpigmentation with antioxidant activity. In a randomized double-blind trial it matched retinol 0.5% for photoaging improvement with less scaling and stinging.

Concentration

0.5–1%

Timeline

~12 weeks of twice-daily use

Pairs with

Vitamin C, Niacinamide, Hyaluronic Acid, Sunscreen

Avoid with

No known conflicts

A fat-soluble antioxidant that neutralizes UV-generated free radicals and prevents lipid peroxidation and oxidative photoaging. It also moisturizes the stratum corneum and has anti-inflammatory activity — and works best alongside vitamin C.

Concentration

0.5–1% (up to 5%)

Timeline

Ongoing with daily use; hydration benefits over several weeks

Pairs with

Vitamin C, Ferulic Acid, Sunscreen

Avoid with

No known conflicts

A plant-derived phenolic antioxidant that neutralizes free radicals and, critically, stabilizes vitamins C and E in formulation. Added to a 15% vitamin C + 1% vitamin E solution it roughly doubles photoprotection against solar-simulated UV — the classic 'Duke' antioxidant complex.

Concentration

0.5–1%

Timeline

Antioxidant support immediate; anti-aging over weeks to months

Pairs with

Vitamin C, Vitamin E, Sunscreen

Avoid with

No known conflicts

An inorganic (mineral) UV filter that absorbs and scatters UV radiation for broad-spectrum UVA and UVB protection (up to ~370 nm). It is chemically inert and less likely than chemical filters to irritate, suiting sensitive skin.

Concentration

Broad-spectrum from ~7%, up to 25%

Timeline

Immediate on application; reapply every 2 hours

Pairs with

Titanium Dioxide, Niacinamide, Antioxidants

Avoid with

No known conflicts