I started using a skincare product two years ago, and only found out later that it hadn't been officially approved.

It was fine for the first two months, but then my facial skin changed drastically. The pores became bigger and the skin became too sensitive to sunlight.

The product supposedly contained hyaluronic acid, collagen, lipposom, liquid lanolin, vitamin C and natural moisturiser. My skin has looked abnormal ever since. Now I'm trying to use as many natural products as possible. What else should I do? - Athikom Kongdee, Bangkok

Skin pores can become more visible due to various factors. Genetics, sun damage, poor exfoliation, lack of hydration and excess surface oil are common culprits.

In your case, some unknown chemicals in the product may have either irritated or dehydrated your skin. Common irritants include fragrances, dyes, ethyl alcohol and some preservatives.

Various substances in skincare products can make skin more susceptible to UV light. Common photosensitisers found in over-the-counter creams are AHA (alpha-hydroxy acids) and vitamin A derivatives like retinol and retinyl palmitate.

However, the effect is reversible in most cases and                  doesn't last long after discon-  tinuing use of the cream.

As for the recovery process, your skin can repair itself in one to two months if you don't keep injuring it. Choose products that contain very few ingredients and little if any fragrance. Avoid those that contain solvents such as propylene glycol and ethanol. Don't use products containing AHA or vitamins A and C, since they can irritate your skin.

Using chemical-free sunscreen can help the repairing process as well.

In any case, it's difficult to provide you with more specific recommendations without seeing you in person, so my advice is to let your skin rest for one to two months and see if it gets better on its own. If it doesn't, consult a dermatologist.