I’ve never pretended that this blog is a skincare blog from a scientific perspective because frankly I’ve never been much of a science student. When I was studying esthetics and realized that I had to refresh my high school chemistry knowledge (I received Cs in high school chemistry) I nearly had a panic attack. As I’ve progressed in my work as an esthetician I’ve realized that science knowledge is key to understanding how skincare products work on the skin and key in helping my clients get great results from both treatments and home care products. But I still need that science to be dumbed down for me or else my mind instantly goes blank.
All of this brings us to the subject of this post – chirality. I wanted to address this issue since two skincare lines I’ve used make sure to explain that they are both “chirally correct”. What does that mean exactly and how does that impact skincare products?
Q: What does “Chirally Correct” mean and why is it important?
A: A molecule is considered chiral if it differs from its mirror image. For example, hold out your hands in front of you. Notice that they are mirror images of each other. If you place your right hand on top of your left hand, you can demonstrate this difference. None of the features of your hands will line up when stacked on top of each other; though they have the same features, they are exact mirors of each other. This means your hands are chiral.
Certain ingredients in glo.therapeutics products are lab produced and will be made of 2 forms: Left (L for left) and Right (D for dextro). These ingredients are mirror images of each other, not exact duplicates. One side of the ingredient is more useful and beneficial to the skin, while the other side is useless. glotherapeutics only uses the purest, highest quality form, making the products superior in the results.
Tecniche has pretty much the same thing to say:
Mother Nature creates molecules with two sides or hands, right and left. For reasons unknown to scientists, some right handed molecules work best on skin, where as some left handed molecules are better received by the skin. It may be a more extensive and expensive route, but it has been Tecniche’s™ life work to only use the ‘hand’ of the lab-neutral molecule that best mimics Mother Nature’s perfect plan (aka: Chirally Correct).
Leatha Questions Chirality:
I have started using a skin care line called Cosmedix and they claim that their products are chirally correct. I don`t know what this means and whether it is a marketing gimmick or if there is some truth to it.
The Left Brain Criticizes Cosmedix:
The term chiral is derived from the Greek work for handedness and a molecule is called chiral if it differs from its mirror image. (A simple way to visualize this concept is to think of your right and left hand. You can`t fit your left hand in your right glove, right? That`s because they`re chiral. You can learn more about the idea here.)
Some chemical reactions produce both the left handed and right handed version of the same molecule. These versions are called isomers. This concept is very important in drug manufacture where the Left and Right isomers may have different chemical properties. If the Left isomer is effective against a given disease, you want a chemical reaction that produces pure Left, not a mixture of Right and Left. So for drugs, chiral purity is very important.
But for cosmetic products, chirality isn`t really an issue. That’s because cosmetic ingredients don`t interact with the biological systems of your body the same way drugs do. So your first guess was correct “ this IS a marketing gimmick!
In their book Physiology of the Skin Drs. Draelos and Pugliese agree with The Beauty Brains (page 116):
A term that is being used lately is chirality. The word chiral is from cheir, the Greek word for “hand”. A chiral molecule is one that cannot be superimposed on its mirror image, just as you cannot superimpose your two hands in a mirror image. Any compound that has four different atoms, or groups, attached to a single carbon is chiral. You need to think about this for a minute or two before you realize that what you are thinking about is an asymmetrical figure, since all chiral compounds lack symmetry by definition.
More and more often, it’s being asked if a product’s chirality is correct. What should be asked is if the product is biologically active. Most chemical compounds in nature are chiral compounds that are biologically active, so they are indeed, correct chirally. Asking if it is “chirally correct” is the same as asking “Is this water in this product really H2O?” There is no such thing as chirally correct, any more than you can be facially correct. What should be asked is, “Does this product have the correct optical isomerism?” By being correct it is biologically active.
So what about some middle ground on this subject. I found the following post on the blog The Science of Beauty – What is Chirally Correct Skincare? I’ll skip quoting the beginning of the post since it contains information I already covered above. Let’s dive in towards the middle of the post:
Well, whilst some skincare ranges contain only naturally derived ingredients, the majority are comprised of laboratory created ingredients. It is much easier and cheaper to synthesise Vitamin E, for example, in a laboratory than to try and extract it from natural sources. Vitamin E can be found in almonds, sunflower seeds, wheat germ oil, amongst other things but the quantities of these ingredients required to acquire sufficient Vitamin E, and the cost associated with extracting it would make the final skincare product exorbitantly expensive.When molecules are synthesised by man they always form in pairs that are the mirror image of each other. So, like your left and right hand, these mirror imaged molecules contain all the same parts but are not identical to one and other. Each mirror image of the molecule is given a prefix to its chemical name – either d or l. So, using the Vitamin E example, the chemical name for Vitamin E is alpha-tocopherol so the mirror images of the molecules are called d-alpha-tocopherol and l-alpha-tocopherol. But even though these molecules are nearly identical (the only difference being the mirror image) only one of the molecules can be used by the human body – in this case the molecule with the d-prefix (d-alpha-tocopherol). So chirally correct skincare contains ingredients that have been tested to ensure that they only contain the active molecule, out of the mirror imaged pair, that can be used by the human body. The molecules are sorted so that only the active molecule is added. With Vitamin E it has already been determined that d-alpha-tocopherol the active molecule so any Vitamin E that is added to chirally correct skincare will have been sorted so that only d-alpha-tocopherol is added. If your skincare is not chirally correct, and the vitamin E molecules have not been sorted, it will be listed in the ingredients as dl-alpha-tocopherol, as it contains a 50/50 mixture of the d-alpha-tocopherol and l-alpha-tocopherol molecules.So what happens if the molecules are not sorted? Generally nothing; however, your skincare will be less potent. When a molecule is made, equal amounts of the l-molecule and d-molecule are created. So, if your skincare range claims to have 10ml of Vitamin E in it, but the Vitamin E has not been sorted to get the chirally correct molecule then your skincare will actually contain 5ml of active Vitamin E and 5ml of a molecule that does absolutely nothing – so your skincare is half as potent as you expect. …Therefore, there is no reason to be concerned if you are using skincare that is not chirally correct that it could be doing you damage, just be aware that it may not be as potent or effective as you think.
Bottom Line: Like so many subject that I present in this blog there are truly opposing perspectives here on the same subject. I think that at the moment I am inclined to agree with those who say that being chirally correct has no place in effective skincare products. What do you think? Please share your opinion below.
Image from photo.photoshelter.com