Retinol is a form of vitamin A and one of the most strongly evidenced ingredients in dermatology for improving wrinkles, acne, and pigmentation. It's the cosmetic version of the prescription drug retinoic acid (Retin-A), converting to retinoic acid in the skin to take effect.
What retinol does in the skin
Promotes cell turnover
It speeds up the cycle of keratinocyte production and shedding to promote skin renewal. The result: smoother fine lines and improved dull tone.
Promotes collagen synthesis
It directly stimulates collagen synthesis by dermal fibroblasts. It also inhibits MMP (matrix metalloproteinase) enzymes that destroy collagen.
Normalizes follicular keratinization
It curbs follicular hyperkeratosis, an acne cause, reducing comedo formation and improving existing acne lesions.
Suppresses pigmentation
It suppresses melanin production and distribution, helping with melasma, spots, and acne marks.
Retinol conversion pathway
Retinol → retinaldehyde → retinoic acid (active form)
The more conversion steps, the weaker the effect but the less irritation. In OTC cosmetics, retinol is the most common; retinaldehyde (retinal) is about 11x more effective than retinol with less irritation and has drawn attention recently.
What is retinol purging?
When starting retinol, acne may actually increase between weeks 2 and 6. This happens as faster cell turnover pushes clogged comedones inside the pores up to the surface quickly. This is "purging," not a worsening of existing breakouts.
Purging usually ends naturally within 4–8 weeks, after which skin becomes clearer than before. Many people misread this period and give up on retinol.
How to start retinol
Step 1: Start at a low concentration
Begin at 0.025–0.1%. Starting high can cause severe dryness, flaking, and irritation.
Step 2: Start 1–2 times a week
Use only 1–2 times a week for the first 2 weeks. As skin adapts, increase to every other day, then every night. This takes at least 4–8 weeks.
Step 3: Use only at night
Retinol breaks down under UV and increases photosensitivity, so use only at night. Next-morning sunscreen is essential.
Step 4: Sandwich with moisturizer (Sandwich Method)
Applying in the order moisturizer → retinol → moisturizer effectively reduces early irritation. Once skin adapts, you can use retinol alone.
What to avoid with retinol
- Using AHA/BHA the same night (alternate days instead)
- Do not use during pregnancy/breastfeeding (including prescription retinoids)
- Be careful not to apply directly on thin skin like the eye and mouth area
Retinol is an ingredient that works the more consistently you use it. Rather than forcing high concentrations for fast results, patience to let skin adapt is most important.