Can you recommend any beauty product that can help lighten dark spots and armpits and remove stretch marks?—MAY

The darkening of underarms, elbows and knees is most likely due to hyperpigmentation, a skin condition that affects more people than you think. It is mainly a result of excess melanin, which can be hereditary, or triggered by sun exposure or pregnancy. In the case of underarms, the area can turn dark as a reaction to your deodorant, plucking or shaving, dead skin build-up or rubbing against tight clothing. Areas like your elbows and knees can also become dark and rough when you forget to exfoliate and moisturize.

The good news is, there are many ways to lighten these areas, and you can even use ingredients you can find in your kitchen. Foods with whitening properties include lemon or calamansi, as well as papaya and milk. You may try using these to lighten dark areas, but keep in mind these will take time (a few weeks) before you see a significant change. Another way to do it is to find a whitening system to suit your needs and budget. Find a soap, lotion/moisturizer or cream that have active ingredients like vitamin C, alpha hydroxy acids (AHA) and licorice extract, which are known to help brighten skin. Some even double as an exfoliant or deep moisturizer, which are also needed to speed up the whitening process. But if you’re looking for a more drastic plan of action, a visit to your dermatologist is a good idea. She may be able to recommend a more potent whitening or bleaching cream to even out those dark spots. She may have a separate concoction for your underarms, since this area can be quite sensitive.

Now, when it comes to stretch marks, well, this can be a little more complicated. We get stretch marks when we grow or gain weight too quickly, which causes our skin to break in some areas. It isn’t a serious thing, but, of course, we all want our skin to look smooth and bump-free. One of the most effective ways to prevent stretch marks is by moisturizing daily, which helps skin become more elastic and pliant. This is one of those times when that old adage, “an ounce of prevention is better than a pound of cure,” applies. Moisturizing daily will help stave off stretch marks. However, if you have them already, try to assess the stage they’re in. The earlier you catch these stretch marks, the easier it will be to minimize them. Their appearance will depend on your skin color: They start out pink, reddish brown, brown or dark brown and eventually fade into a more silvery color. They’re easily treatable when still red or purple, than when they’ve turned silver or white with deep indentations.

Luckily, there are quite a few products out there that help minimize stretch marks. Read the label and look for the following active ingredients: retinoids (proven to increase collagen and elastic production, but not to be used when nursing); glycolic acid (also known as AHA, this boosts collagen production); and vitamin C (works well with glycolic acid). These may also be available in their potent form from your dermatologist. And if you are looking for a faster way to zap those marks, ask your doctor about laser treatments.