How to Use /PHD/ Serums
A step-by-step guide to every /PHD/ serum — how to apply it, when to use it, what to pair it with, and what to avoid. Written for real results on Indian skin.
The universal rules — apply these to every /PHD/ serum
- Cleanse first. Always apply a serum on freshly cleansed skin — residue blocks absorption.
- Dry, don't damp — unless it's HA. Most actives work better on completely dry skin. The only /PHD/ serum that prefers damp application is the 2% Hyaluronic Acid Dewy Skin Serum.
- Pea-sized is enough. More isn't better with actives — it just increases irritation risk on Indian skin.
- Pat, don't rub. Press into skin with fingertips. Rubbing wastes product and stresses the barrier.
- Moisturiser after. Always follow a serum with a moisturiser — otherwise actives can dehydrate the skin.
- SPF every morning, without exception. Active ingredients make skin more photo-sensitive; skipping SPF undoes the work.
AM vs PM — when to use what
Morning serums
- 10% Vitamin C Brightening Serum — antioxidant protection + brightness
- 10% Niacinamide Spot Correcting Serum — oil regulation + tone
- 2% Hyaluronic Acid Dewy Skin Serum — hydration layer under moisturiser
Finish with SPF 60 broad-spectrum. Always.
Evening serums
- 2% Salicylic Acid Anti-Acne Serum — full-face acne treatment
- Salicylic Acid Acne Spot Treatment Gel — targeted on active pimples
- 2% Alpha Arbutin Depigmentation Serum — fades dark spots overnight
- 0.3% Pure Retinol Face Serum — anti-ageing, 2–3 nights/week
- 1% Ceramides Intensive Repair Cream — barrier repair, eczema-prone skin
Always follow with a nourishing moisturiser.
Step-by-step: each /PHD/ serum
Tap any product below to see the full how-to instructions.
2% Salicylic Acid Anti-Acne Serum
Active acne, blackheads, clogged pores
For: Active acne, blackheads, clogged pores.
- Cleanse with a gentle, sulphate-free face wash. Pat completely dry.
- Apply 3–4 drops across the acne-prone area (not just spots — salicylic acid works face-wide to prevent new breakouts).
- Wait 60 seconds for absorption before the next product.
- Follow with a lightweight moisturiser.
Frequency: Start 3 nights/week for 2 weeks, then nightly if no dryness. Use only at night.
Don't combine with: Retinol in the same evening, benzoyl peroxide, or strong AHAs. Pick one treatment acid at a time.
Shop 2% Salicylic Acid Serum →
Salicylic Acid Acne Spot Treatment Gel
Individual active pimples and inflamed spots
For: Individual active pimples, emerging whiteheads, inflamed spots.
- Cleanse at night and pat dry.
- Apply a small dot directly on each active spot (not the whole face — this is a targeted treatment).
- Let it dry for 30 seconds before other products.
- Follow the rest of your routine around the spot (avoid layering retinol on the exact same pimple).
Frequency: Once or twice daily on active spots only, until the spot flattens (usually 2–4 days).
Don't combine with: Other spot treatments on the same pimple — it over-dries and can cause post-acne dark marks.
Shop Spot Treatment Gel →
10% Niacinamide Spot Correcting Serum
Post-acne marks, pores, oily skin, uneven tone
For: Post-acne marks, enlarged pores, oily skin, uneven tone.
- Cleanse and pat dry.
- Apply 2–3 drops across the face, patting in with fingertips.
- Follow with moisturiser. In the morning, finish with SPF 60.
Frequency: Twice daily — morning and evening. One of the safest /PHD/ actives, great for daily use.
Don't combine with: Very low-pH vitamin C in the same application (pair with /PHD/'s stabilised 10% VC — they layer fine).
Shop 10% Niacinamide Serum →
10% Vitamin C Brightening Serum
Dullness, sun damage, uneven tone
For: Dullness, sun damage, uneven tone, antioxidant defence.
- Cleanse in the morning and pat dry.
- Apply 3 drops, patting across the face and neck.
- Wait 60 seconds — Vitamin C penetrates best on dry skin.
- Follow with moisturiser, then SPF 60.
Frequency: Every morning for best brightening results. Optional PM use if skin tolerates it.
Don't combine with: Retinol in the same application (use Vitamin C AM, Retinol PM).
Shop 10% Vitamin C Serum →
2% Alpha Arbutin Depigmentation Serum
Dark spots, post-acne hyperpigmentation
For: Dark spots, post-acne hyperpigmentation, uneven tone on Indian skin.
- Cleanse in the evening and pat dry.
- Apply 2–3 drops across dark-spot-prone areas or whole face.
- Follow with moisturiser.
Frequency: Every night. Safe for long-term daily use unlike hydroquinone.
Don't combine with: Strong exfoliating acids in the same evening — alternate nights if using AHA/BHA separately.
Shop 2% Alpha Arbutin Serum →
0.3% Pure Retinol Face Serum
Fine lines, wrinkles, texture, anti-ageing
For: Fine lines, wrinkles, texture, long-term collagen support.
- Cleanse at night. Wait 10–15 minutes until skin is completely dry (critical — damp skin amplifies irritation).
- Apply a pea-sized amount across the whole face.
- Follow with a rich moisturiser after 60 seconds.
Frequency: Start 2 nights/week for 2 weeks. Move to 3 nights/week for 2 weeks. Then alternate nightly — only if no redness or flaking.
Don't combine with: Salicylic acid, AHAs/BHAs, benzoyl peroxide in the same evening. Never skip morning SPF after retinol nights.
Shop 0.3% Retinol Serum →
2% Hyaluronic Acid Dewy Skin Serum
Dehydration, dryness, every skin type
For: Dehydration, fine lines of dryness, every skin type.
- Cleanse with a gentle cleanser.
- While skin is still damp (within 60 seconds of patting), apply 3 drops.
- Press into skin with palms.
- Follow IMMEDIATELY with moisturiser to seal the hydration in — hyaluronic acid without an occlusive layer evaporates back out.
Frequency: Twice daily — morning and evening.
Don't: Apply on dry skin in low-humidity air — HA can paradoxically pull water from deeper skin layers.
Shop 2% Hyaluronic Acid Serum →
1% Ceramides Intensive Repair Cream
Eczema-prone skin, barrier repair
For: Eczema-prone skin, compromised barrier, dryness, flaking, over-exfoliated skin.
- Cleanse with a sulphate-free, fragrance-free cleanser. Pat skin dry.
- Apply a thick layer on affected areas — face, neck, or body. On active flares, layer generously.
- Press in gently with clean fingertips until absorbed.
- No need to follow with anything extra at night — this cream is the occlusive step.
Frequency: Twice daily during a flare. Once daily (night) for maintenance. Safe for long-term daily use.
Don't combine with: Active acids, retinol, or fragranced products on an active eczema flare — pause all actives until skin calms.
Shop 1% Ceramides Repair Cream →Layering rules — which serums work together
| Combination | Verdict | How to use |
|---|---|---|
| Niacinamide + Vitamin C | ✅ Safe | Layer both in AM. Niacinamide first. |
| Niacinamide + Alpha Arbutin | ✅ Safe | Niacinamide AM, Alpha Arbutin PM. |
| Niacinamide + Retinol | ✅ Safe | Niacinamide AM, Retinol PM. Reduces retinol irritation. |
| Vitamin C + Salicylic Acid | ⚠️ Use on alternate days | VC AM / Salicylic PM is fine. Don't stack same application. |
| Retinol + Salicylic Acid | ❌ Avoid same night | Alternate nights. Pick one treatment acid per evening. |
| Retinol + Alpha Arbutin | ⚠️ Alternate nights | Until your skin builds tolerance. Then safe to combine. |
| Any serum + HA | ✅ Always safe | HA layers with everything. Apply first, on damp skin. |
The 7 biggest mistakes with serums (and how to avoid them)
- Using too much. A pea-sized amount is enough. More just means more irritation.
- Skipping moisturiser after. Actives + no moisturiser = dehydrated, reactive skin.
- Stacking multiple strong actives the same night. Pick one treatment acid (salicylic OR retinol) per evening.
- Not patch-testing. Always apply behind the ear or on the jawline for 2 days before full-face use.
- Giving up after a week. Most actives need 6–12 weeks to show visible results. Consistency > intensity.
- Skipping SPF. This undoes everything. Every morning, no exceptions.
- Applying on broken or irritated skin. Pause actives for 2–3 days and use only cleanser + moisturiser + SPF until the skin recovers.







