How much retinol do you need? 0.075 to 0.3%

What retinol percentage is effective?

Floor 0.075%: a stabilised 0.1% retinol moisturiser beat its vehicle on lines, pigmentation and firmness at 8 weeks in 64 women (Tucker-Samaras 2009), in a pooled analysis of 6 vehicle-controlled studies, 471 women (Farris 2024); 0.075% beat vehicle on fine wrinkling in 54 Japanese women over 26 weeks while 0.04% did less (Kikuchi 2009).

Is 0.5% retinol too much?

0.5% is above the 0.3% ceiling: the trials that compared doses found that above it more stopped adding effect or started adding irritation, so a declared 0.5% reads as above the range, not as stronger. The highest dose tested in leave-on use was 1% (Mellody 2022), and the paper reports more irritation there.

Neither number settles what more does. The trials that compared doses put the ceiling at 0.3%: above it, more stopped adding effect or started adding irritation, which is why a declared percentage above 0.3% reads as above the range, not as stronger.

What does the retinol percentage on a label tell you?

A name that states a percentage ("Retinol 0.3%") is the only amount a cosmetic label ever declares, so it is the one number that can be read against the trials: inside 0.075 to 0.3%, above the 0.3% ceiling, or below the 0.075% floor.

A name without a percentage leaves the position. The rules make a brand list ingredients in descending order of amount down to 1%, and in any order below it, so retinol above the 1% line is at least 1% and retinol below it can be any trace the brand likes. The floor the trials worked from is 0.075%, and a position alone cannot tell you whether a label reaches it.

The retinol percentages in our catalogue

3 labels declare a percentage on the name, read against the trials:

• The Ordinary Retinol 0.5% in SqualaneRetinol is declared at 0.5%: above the 0.075 to 0.3% the trials used.
• The Ordinary Retinol 1% in SqualaneRetinol is declared at 1%: above the 0.075 to 0.3% the trials used.
• Paula's Choice Clinical 0.3% Retinol + 2% Bakuchiol TreatmentRetinol is declared at 0.3%: inside the 0.075 to 0.3% the trials used.

3 labels carry it without a number, so the position is all there is:

• The Ordinary Granactive Retinoid 2% EmulsionRetinol sits 10th of 33, above the 1% line; the label does not say how much, and the trials worked from 0.075%.
• CeraVe Resurfacing Retinol SerumRetinol sits 19th of 33, below the 1% line; the label does not say how much, and the trials worked from 0.075%.
• CeraVe Skin Renewing Retinol SerumRetinol sits 23th of 37, below the 1% line; the label does not say how much, and the trials worked from 0.075%.

Read on

• Retinol: the glossary page what it does, who it suits, where it fits
• Retinol vs Niacinamide
• Retinol vs Vitamin C (LAA)
• Retinol vs Retinal
• Retinol vs Hydroxypinacolone Retinoate
• Retinol vs Retinyl Palmitate
• Retinol vs Retinyl Acetate

Other actives with a dose the trials pinned:

• Niacinamide 2%+
• Vitamin C (LAA) 5%+
• Salicylic acid (BHA) 0.5%+
• Lactic acid 8%+
• Glycolic acid 5%+
• Retinal 0.05 to 0.1%
• Retinyl Retinoate 0.06%+
• Tretinoin 0.025%+
• Adapalene 0.1%+
• Tazarotene 0.045%+
• Azelaic Acid 15%+
• THD Ascorbate 1%+
• Sodium Ascorbyl Phosphate 5%+
• Palmitoyl Pentapeptide-4 0.0003%+
• Caffeine 2%+
• Benzoyl Peroxide 2.5 to 5%
• Tea Tree Oil 5%+
• Hydroquinone 4%+
• Bifida Ferment Lysate 10%+
• Thiamidol 0.2%+
• Cysteamine 5%+
• Menthol 0.1 to 5%
• Peppermint Oil 0.5%+
• N-Acetyl Glucosamine 2%+
• Alpha Lipoic Acid 5%+
• Ammonium lactate 12%+
• Acetylated Hyaluronic Acid 0.1%+
• 4-n-Butylresorcinol 0.1%+
• 4-t-Butylcyclohexanol 0.4%+
• Sphingomonas Ferment Extract 2%+