How can glycolic acid help dark knees?
Glycolic acid removes old cells from the surface of the skin.
Knees have a lot of old cells.
Glycolic acid helps by removing these old cells.
Can’t these old cells fall off by themselves without glycolic acid?
No, they can’t.
In theory, all old cells from the visible layer of the skin have to fall off regularly to make way for the younger cells from the deeper layers of the skin.
But some of these old cells don’t fall off. They are stubborn. These stubborn old cells bind together and form a thin layer on the skin, giving the skin a dull look.
This problem of stubborn old cells is more pronounced in our knees. And here is why…
The skin in the knee area has fewer sebaceous glands than, say, the skin on the face.
Less sebaceous glands means less sebum (oil). Sebum plays an important role in keeping our skin moisturised. When there isn’t enough sebum, the skin becomes dry. Hence the skin in the knee area can become dry very easily.
When the skin is dry, more old cells become stubborn, and fewer younger cells travel upwards to replace old cells. This means there are plenty of old cells in the top layer—and they all form a rough, thick layer on the skin’s surface.
Skin in the knee area is dark due to pigmentation in that area. The rough, thick layer of old cells makes this pigmentation more pronounced.
Will the dark knee problem go away once these old cells are made to fall off by glycolic acid?
Old cells don’t cause the darkness in the knee area. They make it more visible.
The main cause is pigmentation in the knee area.
Unless both problems are addressed, the darkness in the knee area will not reduce.
Pigmentation can exist in cells on the surface and the cells slightly deeper. When glycolic acid gets rid of stubborn old cells from the surface, the pigmentation that’s in them also goes away. So, we can say that glycolic acid helps in reducing pigmentation but only partly.
How much glycolic acid should the product have to be effective?
We need at least 8% glycolic acid.
Can anyone and everyone use glycolic skin?
Don’t use glycolic acid if you have sensitive skin. If the skin on your face is sensitive, it will usually be sensitive in the knee area.
If you have a dark skin tone, glycolic acid works, but be cautious. Glycolic acid can irritate the skin. Irritation leads to pigmentation in darker-skinned people, more than in lighter-skinned people. This does not mean you should stop using glycolic acid. Glycolic acid works beautifully, but just be aware of its side effects and do what’s needed to avoid these effects.
So, what should we do to avoid side effects:
If you have a darker skin tone, start slowly. Start with once a week and gradually increase. Use a good moisturiser afterwards. Also, use sunscreen in the daytime.
What are other ingredients that can help with dark knees?
So, as mentioned earlier, the two problems that need to be addressed are:
~ thick skin (because of accumulation of old cells)
~ pigmentation (darkness)
The darkness in the knees cannot be reduced unless the both thickness and darkness issues are addressed.
Some ingredients that can address the thickness issue are glycolic acid, lactic acid, and urea. Urea needs to be at least 10% concentrated in a product to be effective for this concern.
Niacinamide, kojic acid, and licorice root extract are some ingredients that can address pigmentation issues. Serums are helpful if you have them. If not, look for a moisturiser that has these ingredients.
Finally, a good sunscreen. Without sunscreen, the dark knee problem will keep coming back.
Beware of Acanthosis Nigricans!
If the darkness in the knee area is more like a velvety patch, it could be a skin condition called Acanthosis Nigricans. This condition can only be treated by a dermatologist, and off-the-shelf skincare products cannot help.