Ingredients

A pharmacist-led guide to cosmetic actives. Every ingredient explained with scientific evidence: what it does, how to use it and what to combine it with.

Quina extract: when it's suitable for oily skin
acne
Quina extract: when it's suitable for oily skin
A botanical extract with a sebum-regulating profile that can be effective in formulas for combination or oily skin, w...
Published: 25 May 2026
Zinc sulfate in cosmetics: when it can make sense
acne
Zinc sulfate in cosmetics: when it can make sense
A functional ingredient with antimicrobial and soothing properties, but with important nuances depending on the formu...
Published: 20 May 2026
Sulfur in cosmetics: when it makes sense and when it doesn't
acne
Sulfur in cosmetics: when it makes sense and when it doesn't
It's not an ingredient for everyone, but for oily skin with occasional breakouts, it can make sense if the formula is...
Published: 19 May 2026
Succinic acid: when it makes sense for acne-prone skin
acne
Succinic acid: when it makes sense for acne-prone skin
A lesser-known acid that can fit into routines for occasional blemishes, excess sebum, and mild imperfections, with r...
Published: 19 May 2026
What mandelic acid is used for in the skin: a pharmaceutical guide
acne
What mandelic acid is used for in the skin: a pharmaceutical guide
Mandelic acid exfoliates more gently than other AHAs, helps with acne, blemishes, and dull tone, and is usually bette...
Published: 05 May 2026
Retinal (Retinaldehyde): What It Does for Your Skin and How to Make the Most of It
acne
Retinal (Retinaldehyde): What It Does for Your Skin and How to Make the Most of It
Retinal is an effective cosmetic retinoid for wrinkles, texture, and acne. I'll explain what concentration to use, ho...
Published: 03 May 2026
Ketoconazole on the skin: what it's for and when it makes sense
acne
Ketoconazole on the skin: what it's for and when it makes sense
Ketoconazole on the skin: what it's for, how to use it, and what the evidence says about seborrheic dermatitis and fa...
Published: 03 May 2026
The Truth About Salicylic Acid: What the Science Says
acne
The Truth About Salicylic Acid: What the Science Says
Pharmaceutical guide to salicylic acid: what it really does, what skin types it's suitable for, how to use it without...
Published: 02 May 2026
Azelaic acid in cosmetics: for spots, redness, acne
acne
Azelaic acid in cosmetics: for spots, redness, acne
Azelaic acid is a very interesting dermo-cosmetic active ingredient for skin with hyperpigmentation, acne-prone skin,...
Published: 02 May 2026

What are cosmetic active ingredients

Cosmetic active ingredients are the components responsible for making a product do what it promises. Unlike excipients (which provide texture, preservation or fragrance), actives are the ones that produce a real, measurable effect on the skin: stimulating collagen, inhibiting melanin, strengthening the skin barrier or accelerating cell renewal.

The problem is that most brands do not explain which actives they use, at what concentration or why. This pharmacist-led guide to cosmetic ingredients was created to change that: each article analyses an active ingredient with the available scientific evidence, without exaggeration or empty promises.

How to use this ingredient guide

Each article in this guide includes a summary card with the INCI name, effective concentration, potency, recommended skin type, routine step and compatibility with other actives. You will also find information on use during pregnancy and verifiable scientific references.

All content is written and reviewed by a licensed pharmacist with over 20 years of experience. This is not a standard cosmetic ingredient list — it is a professional guide designed to help you make informed decisions about your skincare.

Arancha Grediaga
Author and reviewer
Pharmacist · Dermocosmetics Expert · COFA License #6497
+20 years of community pharmacy experience · Technical Lead at EVUE Cosmetics