Retinol and exfoliating acids (AHA, BHA) are among the best-documented actives in cosmetics. Introduced the wrong way, though, they can cause dryness, redness and a tingling feeling. Here are the questions people ask most often before getting started, with straightforward answers.
What is the difference between retinoids and exfoliating acids?
- Retinoids (retinol, retinal, retinyl palmitate…) are derived from vitamin A. They act on skin renewal and are used in particular in routines targeting the look of fine lines, texture and dark spots.
- AHAs (glycolic acid, lactic acid, mandelic acid) are water-soluble. They exfoliate the surface of the skin and are often used for dull complexions and rough textures.
- BHA, especially salicylic acid, is oil-soluble. It gets into the pores and suits combination to oily skin, blackheads and blemishes.
- PHAs (gluconolactone…) have larger molecules, so they are gentler. They are often recommended for sensitive skin.
In short: acids exfoliate the skin, while retinoids act on skin renewal. That's why stacking them too early increases the risk of irritation.
Which active should you start with?
It all depends on your main concern:
- Fine lines, firmness → retinoid first
- Enlarged pores, blackheads, dull complexion → acid first
- Sensitive skin or a weakened skin barrier → PHA or low-strength lactic acid
The golden rule: just one active for the first 4 to 6 weeks. If irritation occurs, you'll know exactly which product is responsible.
What concentration and frequency to start with?
Retinol
- Concentration: around 0.1 to 0.3%
- Frequency: 2 evenings a week (for example Monday and Thursday)
- Amount: a pea-sized drop for the whole face
- If all goes well after 2 weeks, move to 3 evenings a week, then gradually to every other evening.
Acids
- AHA: around 5 to 10%, 1 to 2 times a week
- BHA (salicylic acid): 0.5 to 2%, 1 to 2 times a week
- Only increase the frequency if your skin tolerates it. There's no need to use them every day.
Note: in the European Union, retinol, retinyl acetate and retinyl palmitate are now limited to 0.3% retinol equivalent in most cosmetics, and to 0.05% in body lotions. Always check the concentration stated on the product before buying.
Can you use retinol and acids in the same routine?
At first, avoid applying them on the same evening. The simplest method is to alternate:
| Day | Evening routine |
| Monday | Retinoid |
| Tuesday | Hydration only |
| Wednesday | Acid (AHA or BHA) |
| Thursday | Hydration only |
| Friday | Retinoid |
| Weekend | Hydration only (rest) |
Once your skin has adjusted, you can fine-tune this routine with a dermatologist's advice.
Are tingling and peeling normal at the start?
Slight dryness, light flaking and a feeling of tightness are common during the adjustment phase, usually for 4 to 6 weeks.
However, stop using the product and see a dermatologist if needed if you notice:
- burning or intense stinging
- persistent redness or swelling
- blisters, oozing or significant itching
If irritation occurs, pause retinol and acids, and focus on a gentle cleanser and skin-barrier-supporting care for a few days up to 2 weeks.
How can you limit irritation?
- The sandwich technique: moisturiser → retinol → moisturiser.
- Apply to completely dry skin: skin that's still damp absorbs faster and gets irritated more easily.
- Avoid the eye contour, the lips and the sides of the nose, where the skin is thinner.
- Pair with soothing and hydrating ingredients: squalane, ceramides, centella asiatica (madecassoside).
What morning routine should you follow?
Sun protection of at least SPF 30 is essential when you use retinoids or exfoliating acids, because they can make the skin more sensitive to UV.
- Apply it every day, even on cloudy days or indoors.
- Reapply in case of prolonged exposure.
- Keep retinoids for the evening only.
Can you use retinol during pregnancy?
Retinoids are generally not recommended during pregnancy or when planning a pregnancy. If you are breastfeeding or have a skin condition (eczema, rosacea…), ask your doctor or pharmacist for advice before you start. This article is for information only and does not replace medical advice.
How do you choose your first products?
The Korean cosmetics market today offers a very wide choice of retinols and acids, and it's easy to get lost. The right reflex: favour products whose ingredient list and concentrations are clearly stated.
On Piyonna, an online K-beauty shop, you can compare beginner retinols, gentle AHA, BHA and PHA toners and serums, and skin-barrier-supporting care all in one place. Read the product pages, check the ingredients and concentrations, then start with the gentlest option.
- Retinol for beginners: MaryNMay Retinol 0.1% Bakuchiol Cica Serum
MaryNMay Retinol 0.1% Bakuchiol Cica Serum
- Gentle acid: SOME BY MI SOMEBYMI AHA BHA PHA 30 Days Miracle Toner 150ml
SOME BY MI SOMEBYMI AHA BHA PHA 30 Days Miracle Toner 150ml
- Hydrating or soothing care: MEDIHEAL Hyaluronic Acid Deep Moisture Pad
MEDIHEAL Hyaluronic Acid Deep Moisture Pad
Key takeaways
- Introduce only one active at a time.
- Start with a low concentration, 1 to 2 times a week, then increase over 4 to 6 weeks.
- At first, don't combine retinoids and acids on the same evening: alternate.
- Retinoids in the evening only, at least SPF 30 in the morning.
- If irritation is significant, stop and focus on hydration and supporting the skin barrier.
- Pregnancy, breastfeeding or a skin condition: ask a healthcare professional for advice.
FAQ
Should you stop retinol in summer?
It isn't mandatory, but during periods of strong sunshine, reduce the frequency and apply sun protection diligently.
Can you combine retinol and vitamin C?
Yes, generally by splitting the two: vitamin C in the morning, retinol in the evening.
How long before you see results?
Changes in texture and radiance often appear after a few weeks. For fine lines, generally allow at least 3 months of regular use.
Sources
Piyonna Global Beauty Supporters - La Peau · Minseo Choi
