Skin Lightening and Skin Bleaching: The Difference

Skin lightening and Skin Bleaching are both terms to describe the voluntary process of decreasing darkness or increasing paleness in the color of one’s skin.  This is Part 1 of a multi part discussion and should include everything you need to know. The terms are used interchangeably, but they should not be.  The Difference between these terms is not nuanced.  They differ significantly.  They are approached differently.  The goals and endpoints are also different.   The difference must be appreciated when embarking on the journey to lighten dark spots on your own skin, improve melasma, to change your complexion altogether.

I have searched the literature and popular culture for accurate definitions for and boundaries of each term.   And I have not been successful in finding complete consensus or agreement.   Nonclinical practitioners of skin lightening and skin bleaching and people who do it themselves sometimes use the terms as the same thing.  Other practitioners draw a distinction.  Some people who lighten their skin are insulted by calling the process they use “skin bleaching”.  Dermatologists and Estheticians, on the other hand, tend to have more specific, consistent, and stable definitions of the terms.  They must be, in order to be able to place their patients in the proper treatment categories.

The purpose of this blog post is to provide workable and sensible definitions of the terms, which should allow people who seek to improve or change their skin to make the best choices about which products and therapies they will seek out and use.

The Fitzpatrick Scale

The Fitzpatrick scale is a numerical classification scheme for skin color in humans that was developed in 1975 by Thomas B. Fitzpatrick, an American Dermatologist.  He devised it as a vehicle to estimate the response of different types of skin to UV light.  It was initially developed on the basis of skin color to measure the correct dose of UV-A radiation for PUVA therapy (a therapy utilizing skin-sensitizing compounds when exposed to radiation that can treat a variety of skin diseases).   Dose estimations commonly failed when methods based on hair and eye color resulted in too high UVA doses for some patients.  The scale he created was based on the patient’s reports of how their skin responds to the sun and what the pigmentation or shade looks like (phenotype).  The Fitzpatrick scale remains a recognized tool for dermatological research into human skin pigmentation.

The Fitzpatrick scale is adaptable to formulating good definitions of skin lightening and skin bleaching.  Although within each level of the scale, there is variation of tones, but the scale is convenient and easy to use.

 

Skin Lightening

Skin lightening is simply the change of skin color or skin tone (shade) to a lighter tone.  In most cases, it starts on the Fitzpatrick scale at a level of VI to III and changes it to at least one or one-half levels.  The goal is usually not to achieve level I from level VI.

The change is typically reversible and temporary.  It must be maintained or over time it will likely revert back to the original Fitzpatrick level.  Skin lightening is normally used to correct an over-pigmentation or hyperpigmentation problem in a specific spot or area of the skin.  But it clearly is used to lessen pigmentation over broad areas of skin.  For example, to take a dark or darker complexion and make it a “fair complexion”.  Although most people choose the face and hands to lighten, or in some cases, their private areas and underarms, others use skin lightening products to decrease darkness over the entire body.

Subjects who have level II skin tone rarely want to change to level I.  These days, people with level I or Level II skin tones on the Fitzpatrick scale are more apt to want to darken their skin to Level III using suntanning, tanning beds using a uv-safe source, chemical sunless tanning solutions or injections of a hormone called Melanotan.  Melanotan II is not legal in the US and many other countries for this purpose.

 

 

Skin bleaching

Skin bleaching is the change of skin color or skin tone that is Level VI to III to level I or a theoretical level 0 (no pigment).   Realistically, there is no option to control the change to any intermediate level during the transition.  It is all-or-none.  Unlike skin lightening, it is permanent.  It is Depigmentation.  It is not a modulation of melanin production.  It is the knock-out punch of melanin-producing ability in the area being treated.

Whereas skin lightening can address hyperpigmentation that occurs with dark spots, moles, melasma and post-inflammatory hyperpigmentation.  Skin bleaching is not.  When the skin is bleached, all of melanin and the cells which produce it are eliminated.  There is no pigment remaining in the area treated.  It is implausible that DEPIGMENTING a mole or area with melasma will produce a better cosmetic result if the area has no pigment versus when the area is hyperpigmented.

Skin lightening in general is a matter of esthetics.  Skin Bleaching is intended to be a matter of medicine and treatment of disease, which is and has been misused for esthetic purposes.

For example, the only recognized and approved use of skin bleaching agents is for Vitiligo, an autoimmune disorder of the skin characterized by skin depigmentation in a random and patchy pattern.  Skin Bleaching agents and techniques can be used to depigment the areas of skin that still retain pigment, to create a uniform depigmented appearance.

 

 

It should be noted that depigmentation is just one treatment option that can be chosen for vitiligo.  Although depigmentation may produce a more socially acceptable appearance, The removal of all the pigment of skin may come at a cost.  Because melanin in the skin protects us from radiation that can cause cancers of the skin, its removal increases those risk significantly.  Depigmentation thus confers on the patient a lifetime of high SPF sunscreen use, meticulous sun avoidance and skin screening to catch any signs of skin cancers.

As of the date of this blog post, there is a new option for re-pigmentation for depigmented areas in vitiligo sufferers that is now FDA-approved for home use.  It is called ruxolitinib (brand name: Opzelura), a medication that is supplied in cream form.  It binds to Janus-associated kinase (JAK) receptors on the surface of the immune cell which have been abnormally programed to kill melanocytes, the skin cells which produce melanin pigment. Once the immune cells are inhibited, new melanocytes are able to grow into the area and slowly the pigment returns to patients’ skin.  Phase 3 clinical trials that found 30% of patients using the cream regained 75% or more skin re-pigmentation on the face and roughly 20% of patients regained at least 50% or more re-pigmentation on their body after 24 weeks.

 

One tube of the medication retails for $2000 USD for a single tube that may last one month.   Duration is intended for 8 weeks.  There are suggestions that there is even more restoration of pigment with longer use.

 

Why do people lighten skin?

The answer to this question is both simple and complex.  A complete answer could easily be the subject of entire book with hundreds of pages or certainly a blog post of its own.  The answer would have to include historical, political, cultural, social, and psychological factors and perspectives.  But we can outline a discussion that includes reasons and motivations and provide some context.

The simple take is to remove a discolored lesion of flaw on an area that people can see that detracts from the person’s esthetic preference.  Melasma is a good example.

The more complex take is the social pressure inflicted upon dark people by historical influences such as colonialism to adopt the features, beauty standards including light or white skin tone of the culture who colonized and oppressed them.  Even when the oppression has been removed, a self-loathing ironic remnant, the beauty standards of the dominant culture, persists within the social group.   The dominant culture was definitely complicit with enforcing their own Eurocentric beauty standards and inflicting self-loathing in the cultures they oppressed.   Here are some not-so-subtle examples.

And another example.   It was not a one-off, by any means.

 

In the post- Slavery and post- “Jim Crow” African American community, this is called “Colorism”.

 

 

And there tends to be a counterreaction to black people even considering altering their skin color in America, although many of their White counterparts darken their skin freely, without any question of their motivations or psychology.

 

How Skin Lightening and Skin Beaching Products Work

Whether a product is a skin lightener or a bleaching agent will depend on how it affects the Melanin production process or the Melanin-producing Cell.

Melanin Production is a complex process that I will try to simplify.  Keratinocytes, the chief cell of the skin which performs a barrier function and a protection from UV radiation contains melanin deposits.  These deposits assort around the nucleus of the less mature keratinocytes in the deeper layers of skin, underneath the fully keratinized layers lacking nuclei.  The melanin deposits absorb uv radiation and prevent changes to the DNA in the nucleus.  When they fail to capture the radiation, and the DNA is mutated, the changes are sensed in the nucleus.  In response, the keratinocytes synthesize a hormone called Pro-opiomelanocortin (POMC) is a hormone that can be cleaved into several smaller biologically active hormones.  One of them, Melanocyte Stimulating Hormone (MSH) is released from the keratinocyte.  MSH, also called Melanocortin, is then released into the intracellular space, where it binds a specific receptor (MC1R) on the surface of neighboring melanocytes, the cells which synthesis melanin, which are located in the basal layer of skin.  Interestingly, Melanotan II, the hormone referenced previously that some people have used to darken their skin is a synthetic analogue of MSH.

 

The binding of MC1R cell-surface receptor initiates a series of reaction which produce activation of a gene which produces the Master Controller of the genes (MITF-M or Microopthalmia-Associated Transcription Factor).  MITF then turns on the genes that encode the enzymes which synthesis the large melanin polymers.  Those enzymes are Tyrosinase (TYR), Tyrosinase-Related Protein (TYRP-1) and Dopachrome Tautomerase (DCT).   We will come back to this point later.

Skin Lighteners inhibit Specific Points in the Melanin Biosynthesis

It should be obvious that skin-lighteners work by inhibiting any specific points in the pathway.  The most common inhibition point of inhibition are the enzymes, which directly synthesize melanin, specifically Tyrosinase.  Because there are 50,000 known inhibitors of Tyrosinase (Human, mushroom/fungal and other species), it is impossible to list all of them.  Some are natural.  Chemists have synthesized some using the structural motifs present in compounds known to inhibit Tyrosinase, and some are simply random modifications of natural Tyrosinase inhibitors.

Tyrosinase is an interesting enzyme. It is a metallo-enzyme, meaning its function is dependent on the presence of a metal ion, which participates in the biochemical reaction

and then to dopaquinone.

The metal ion in the enzyme catalytic site is the Copper (Cu) ion.  It is capable of changing its oxidation state or charge by giving up an electron or accepting one.  There are 2 Copper ions in the site.  They are stabilized by polar nitrogen residues of histidine groups on the proteins which are specifically folded to produce the 3-Dimensional site.  The non-accidental structural motif, understandably, is conserved in Tyrosinase enzymes across species including other animals and fungi.

Inhibitors may work by competing with L-Tyrosine for the active site, making tyrosine less available to form melanin.   Some work by extracting the Copper from the Tyrosine from the active site, making the normal reaction less able to occur.  Some work by modifying chemical groups of amino acids within the enzyme active site or at other sites which cause a disturbance in the active site, such that tyrosine cannot.  Regardless of the mechanism of the inhibition, not all of the 50,000 inhibitors are strong or effective at inhibition.  Not all have been tested with the gold standard ones used in skin-lightening products. Not all are able to penetrate the skin and get to the melanocyte cells where they can impact tyrosinase function.   Not all are stable, meaning some may not be able to exist in creams, lotions and solvents in an effort serve a role in skin-lightening, before decomposing into something else which has no inhibitory capacity.   And certainly, not all are safe.  Some inhibit other critical enzymes and protein structures in the body, that may cause problems and eliminate them from being used in products.

 

Thankfully, they follow similar methods of inhibition of Tyrosine and can structurally be organized into families based on their chemical structure. Some of them may be familiar to you because they appear in skin lightening products you use or have used.  Let’s look at a few.

Continued in part 2.

Also, Visit Skinsurrection website, for our list of effective rapid skin lighteners products,  Skinsurrection on Facebook or IG for some additional information and options.