Which scores higher with the experts?
SkinCeuticals C E Ferulic holds a Guru Score of 79%, ahead of Paula's Choice 10% Azelaic Acid Booster at 74%. The first draws on 28 independent expert reviews, the second on 19. On the experts' own numbers that puts C E Ferulic in Approved territory and 10% Azelaic Acid Booster in Mixed.
What do the experts say about C E Ferulic?
SkinCeuticals C E Ferulic carries a Guru Score of 79% from 28 independent experts. This serum has solid clinical backing and delivers results for those who tolerate L-ascorbic acid well, but experts genuinely split on whether the £165-185 price tag is justified now that the original patent has expired and affordable alternatives with similar formulas exist. Those with sensitive skin or darker skin tones may find the concentration irritating and should patch-test first, as L-ascorbic acid at this strength triggers redness in a significant portion of people. For normal to dry skin types who know they handle the active well, dermatologists note it remains reliable and worth keeping; for everyone else, gurus suggest exploring cheaper dupes with the same active form before committing to the premium price.
What do the experts say about 10% Azelaic Acid Booster?
Paula's Choice 10% Azelaic Acid Booster carries a Guru Score of 74% from 19 independent experts. The formula layers beautifully and doesn't pill for most people, earning praise for its elegant texture compared to grittier azelaic acid options. Gurus consistently highlight its range: it tackles redness, acne, post-inflammatory hyperpigmentation, and even rosacea, and remains safe in pregnancy when azelaic acid alone is the concern (though the added salicylic acid introduces caution). The one genuine caveat is that azelaic acid can pill and feel less cosmetically refined, so applying it at night rather than morning works best; a few people also found the salicylic acid eventually felt like too much exfoliation alongside other actives like tretinoin, so those already using strong retinoids may want to ease in slowly or use it just once or twice a week.
Which should you choose?
On the experts' scores SkinCeuticals C E Ferulic comes out ahead, 79% to 74%, a gap of 5 points. It has 28 experts behind it against 19 for Paula's Choice 10% Azelaic Acid Booster. C E Ferulic is most often recommended for mature skin, 10% Azelaic Acid Booster for sensitive and acne-prone. Both are independently verified on the Guru Index, so either is a sound pick; let the use case and your budget settle it.