Retinol: what concentration and how many drops
A pea-sized amount for the entire face, with concentration gradually increased over months. Retinol dosage depends on both the application schedule and the product's concentration.
Concentration: 0.1 to 1%
Products on the market range from 0.1% to 1% retinol. Starting at 0.1% or 0.2% is the rule, regardless of skin type. Move up to 0.3% after three months, then to 0.5% after six, if there are no adverse reactions.
Above 1%, we enter the realm of retinoic acid, which requires a prescription and a different framework. Retinol concentration is not a competition: an active ingredient used regularly at 0.2% does more than one abandoned at 1%.
How much product to apply
The equivalent of a pea-sized amount for the entire face, or three to four drops if it's a serum. Apply to clean, perfectly dry skin: damp skin increases penetration, and with it, the risk of irritation.
Avoid the immediate eye area, the sides of the nose, and the corners of the mouth during the first few weeks. These areas are thinner and react first.
How many times a week
Weeks one and two: every third night. Weeks three and four: every other night. Then daily if the skin tolerates it. This progression may seem slow but saves time: too rapid an increase causes a phase of discomfort that almost always leads to abandonment.
For sensitive skin, start with one application every five days for a month. The final rhythm is the same, but the path is twice as long, and this is what allows you to succeed.
The sandwich method
For very reactive skin, apply a layer of moisturizer before retinol, then a second one after. Penetration decreases, comfort increases. The results take longer to appear, which is not a problem: a six-month regimen does more than one abandoned after one month.
Hyaluronic acid can be included without counting as an additional active ingredient. However, no acids and no scrubs on the same evening: combining them produces exactly the irritation you were trying to avoid.
Preserving an unstable active ingredient
Retinol degrades in light and air. A tube or airless pump is a good sign; an open jar used with each application is much less so. Six months after opening, store away from light.
This is also why it's applied in the evening: the molecule performs better in the dark, and daily sun protection becomes mandatory throughout the entire regimen.