Many wonder why professional skin care products cost more than the department store products.  One reason may be because they are chirally correct.

I remember the first time I heard of chirality and it’s importance.   Many things became clear at that moment.  Why some products with specific active ingredients worked and others didn’t, why some irritated my skin while another didn’t, etc. 

Louis Pasteur first recognized the importance of chirality in 1848.  Chirality is derived from the Greek word chir, which means “hand”.  Basically, it is saying that compounds have sides or hands that are mirror images of each other.  Your hands are a good example of this.  They look the same but you can’t fit them on top of each other with palms facing the same direction no matter how hard you try.  A left hand glove doesn’t fit a right hand. 

To identify which molecular “hand” is being represented, scientists use “D” for dextrorotary-which means the polarized light rotates right, and “L” for levorotary- which means the light rotates left. 

In order for a product to be truly effective, it must be chirally correct.  Just as that left handed glove doesn’t fit the right hand, your body will not accept a left handed compound to do a right handed job, and visa versa.  The body is selective about which part of a compound it can use, which is useless, and which may even be harmful. 

Thalidomide is a good example of this selectivity.  Thalidomide was a drug used in the early 60’s for morning sickness.  Unfortunately, both the D & L forms were given and the L molecule caused horrific birth defects.  In 1979, scientists separated the two hands and discovered that the D form works well and causes no defects, while the L side caused the defects.

More examples include vitamin C and limonene.  One form of vitamin C, L-ascorbic acid, is very effective and readily accepted by the skin.  The other form, D-ascorbic acid, is basically useless.  Limonene is a compound found in citrus fruits.  D-limonene is used for industrial cleaners and degreasers.  It is know to cause allergic reactions and promotes mutations in human embryos as well as promoting free radicals.  The L-limonene molecule suppresses tumor growth (especially melanoma) and fights free radicals.  I know which one I would rather put on my face.

Hopefully by now, you see why you want your products to be chirally correct.  But where do chirally correct ingredients come from?  Some compounds are chirally correct in their natural form.  Others are artificially created in the laboratory through a meticulous separation process called isolation.  Racemic molecules (those containing both the L and D hands) are split into the two hands so the correct form can be isolated and extracted.  This is a time consuming process which is responsible for the increased ingredient cost.  I think everyone would agree it is worth it to have a product that is effective vs. one that doesn’t work at all or worse yet, causes negative side effects.