Ingredient Glossary

Salicylic acid is a beta-hydroxy acid (BHA) derived from willow bark. It's oil-soluble, meaning it penetrates deep into sebum-filled pores to dissolve dead skin, blackheads and microcomedones. It's the gold-standard topical ingredient in dermatology for acne-prone and combination skin.

At 2%, it's strong enough to clear active breakouts without the stinging or flaking most people associate with acne treatments.

Niacinamide (vitamin B3) is one of the most studied ingredients in dermatology. It regulates sebum, reduces hyperpigmentation, strengthens the skin barrier, and calms redness — all from a single molecule.

At 10%, it visibly fades dark spots from post-acne marks and sun damage over 8–12 weeks of daily use. It's safe to layer with almost any other active, which is why it appears in multiple /PHD/ formulas.

Vitamin C is a potent antioxidant that neutralises free radicals generated by UV exposure and pollution, while simultaneously inhibiting melanin production. The result: brighter, more even-toned skin and visibly firmer texture over time.

/PHD/ uses 10% stabilised Vitamin C — potent enough to shift tone, gentle enough for daily morning use under sunscreen.

Hyaluronic acid is a humectant your body already produces — it can hold up to 1,000× its weight in water. Topical application plumps the skin, softens fine lines and restores a dewy, hydrated finish that lasts.

/PHD/ uses multi-molecular-weight hyaluronic acid so hydration reaches multiple layers of skin — not just the surface. It's built into almost every /PHD/ serum and moisturiser so actives never work on dehydrated skin.

Alpha arbutin is a naturally-derived tyrosinase inhibitor — it blocks the enzyme that triggers melanin production, stopping new dark spots from forming while gently fading existing ones. Unlike hydroquinone, it's safe for long-term use.

At 2%, it's clinically validated to reduce pigmentation intensity over 8 weeks in Indian skin tones.

Tyrobright™ is a modern brightening active built around a tyrosinase-inhibition mechanism similar to alpha arbutin, but delivered as a multi-molecule complex. It targets pigmentation at multiple points in the melanin production pathway — which is why it's particularly effective on stubborn patches that haven't responded to single-active treatments.

Gentle enough to pair daily with Vitamin C and Niacinamide, Tyrobright™ is a signature /PHD/ inclusion in advanced brightening serums.

N-Acetyl Glucosamine — or NAG — is a naturally-occurring amino sugar that inhibits the glycosylation of tyrosinase, the enzyme responsible for melanin production. In simple terms: it shuts down pigment production before it starts. Clinical studies show that NAG combined with niacinamide is significantly more effective at fading hyperpigmentation than either ingredient alone.

Bonus: NAG is a precursor to hyaluronic acid, so it also supports barrier hydration while it corrects tone.

Retinol is a vitamin A derivative that speeds up cell turnover, boosts collagen and smooths fine lines — the most clinically validated anti-ageing ingredient in existence.

/PHD/ uses a 0.3% encapsulated retinol formula designed for gradual tolerance-building on Indian skin, which is more prone to post-inflammatory hyperpigmentation from overuse. Start 2× a week, build up slowly.

Peptides are short chains of amino acids that act as signalling molecules — they tell your skin cells to produce more collagen, elastin and hyaluronic acid. Over time, this translates to firmer, bouncier, more resilient skin.

/PHD/ formulations combine signal peptides (like Tripeptide-1 and Palmitoyl Tripeptide-1) with carrier peptides (like Palmitoyl Tetrapeptide-7 and Myristoyl Hexapeptide-5) for maximum bio-availability.

Peptazin™ is a multi-peptide complex that pairs signal peptides (which tell fibroblasts to produce more collagen and elastin) with neuro-peptides (which relax micro-tension and reduce inflammation). The result: calmer skin, faster post-breakout recovery, and visibly smoother texture over time.

In /PHD/'s Salicylic Acid Acne Spot Treatment Gel, Peptazin™ works alongside salicylic acid to speed up the healing of active acne and minimise the post-inflammatory marks pimples tend to leave behind. Formulated to work at low concentrations, it delivers measurable recovery without the irritation retinoids can cause — making it safe for sensitive, acne-prone skin.

Ceramides are naturally occurring lipids that make up 40–50% of your skin's outer barrier. When that barrier is compromised — by over-exfoliation, harsh actives, pollution, or eczema — skin becomes dry, reactive and inflamed. Topical ceramides replenish what's been lost.

/PHD/ uses a multi-ceramide complex matched to the ratio found naturally in human skin.

Panthenol (pro-vitamin B5) is a humectant + emollient that soothes irritated skin, locks in hydration and accelerates barrier recovery. It's the ingredient dermatologists reach for after procedures and for patients with rosacea or eczema.

/PHD/ builds panthenol into its sunscreen as the hero calming agent and layers it alongside every strong active (salicylic, niacinamide, alpha arbutin, HA, ceramide cleanser) so the barrier stays supported even when you're using retinol-adjacent or acne-fighting actives.