What’s the best skin lightening ingredient? Episode 35

Do skin bleaching products really work? Are the ingredients safe? This week Randy and I explain everything you need to know about skin lightening.    

Show notes

Beauty Science News: 7 ways to spot a real expert

As you know we like to promote skeptical thinking, especially when it comes to beauty products. I found an interesting article from Forbes that gives 7 ways to tell you’re dealing with a real expert and not someone who’s just faking it.

  1. Real experts focus on their field, not themselves.
  2. Real experts have no trouble saying: “I don’t know.”
  3. Real experts demonstrate intellectual honesty.
  4. Real experts show intellectual curiosity.
  5. Real experts know when and how to share.
  6. Real experts know when and how to improvise.
  7. Real experts cannot help but teach.

Question of the week: What’s the best skin lightening ingredient?

Hannah from Australia asks…What’s in skin whitening products (or dark spot correctors or age imperfection correctors, or a million other confusing names.) What is it that’s bleaching away dark spots and is it good for you?

To understand skin lightening you first have to understand skin darkening. So let’s talk about what causes hyperpigmentation.

Causes of hyperpigmentation

Hyperpigmentation means your skin produces too much melanin. Melanin is the pigment that colors your skin, hair and the iris of your eyes. It comes from the Greek term meaning “dark.” Melanocytes are cells that actually create the pigment particles.  Melanosomes are little vesicles, or capsules, that hold the melanin and carry them to various parts of the skin.

There are 2 basic causes of HP. Not surprisingly, both involve melanocytes which are the pigment producing cells in your skin.

1. If the melanocytes increase the amount of melanin they produce, this is called  Melantotic HP (melan-tot-ic)

2. If the melanocytes make the same amount of pigment but the NUMBER of melanocytes are increased, this is called Melanocytic HP (melano-cy-tic). Both conditions lead to increased melanin.

HP is further classified by WHERE this excess pigment is: If its in the outer layer it’s called Epidermal HP In the middle it’s called Dermal HP. There are many different types of HP…here are some of the most common.


Everyone is familiar with freckles but I bet you didn’t know that they are technically called  (ephelides) e-fel-i-deeze.  These are melantotic which means your skin has a normal number of melanocytes but they produce more pigment. And the more you are exposed to the sun, the more freckles you’ll get and the darker they’ll become. Also, freckles are kind of the cute version of skin HP.

Age spots

Age spots are formally known as Solar Lentigines (len-tij-in-eeze ) and they are  small brown patches on the skin. As the name implies, they are caused by sun exposure.  These used to be called “liver spots” because they were associated with liver problems that occur as you age. Lentigines are melanocytic which means they are caused by the creation of MORE melanocytes.  While these are triggered by sunlight, once they’re formed they pretty much stay stable in their color even if you get more sun exposure.

Post inflammatory HP (PIH)

This is skin darkening that occurs as a result of skin injury or trauma. As part of the healing process the melanocytes kick into high gear and produce more pigment. These spots may become darker if exposed to sunlight. Two examples: dark marks from acne. Have a zit which is infected, the trauma causes the “scar.” Do you know another area of the body that’s prone to PIH? Armpits! Shaving your pits causes some micro trauma which triggers melanin production. A lot of people complain about dark armpits. Even rubbing of clothing agains armpits can cause this.


It causes brown to gray-brown patches on the face. Most people get it on their cheeks, bridge of their nose, forehead, chin, and above their upper lip. It’s caused by sun exposure but may be triggered by hormones so you can get it due to pregnancy or taking a contraceptive pill. In fact, it’s so common that it’s called “the mask of pregnancy.”

Other conditions

Acral melanosis usually located on the acral areas of the fingers and toes. It is mostly seen in newborns or during the first years of life. Not very common. Tinea versicolor – typically occurs on the chest and it is caused by yeast growing out of control. It is one of the most common skin diseases in tropical and subtropical areas of the world.

How to treat HP

For each of these conditions, treatment depends on WHERE the pigment is. For Dermal HP – there’s not much you can do. Not much helps with this except for certain lasers. You basically have to cover it up. Epidermal HP – The good news is that most common types, like freckles and age spots, are epidermal so you have several treatment options.

  • Topical treatments – creams and lotions
  • Abrasive methods – chemical peels (combined with topical)
  • Surgical methods (Dermabrasion, Cryosurgery, Lasers)

Since Hannah asked about creams and lotions, we’ll limit out discussion to the pros and cons of skin lightening creams and lotions.


What is HQ and how does it work?
HQ , like many skin lightening ingredients, is a phenolic compound. That means it contains a 6 carbon ring with an OH group attached. This structure allows it to inhibit melanin synthesis by acting as a substrate for tyrosinase. Tyrosine, an amino acid, is acted upon by the enzyme tyrosine to form melanin. These phenolic compounds “interrupts” this reaction by giving the tyrosine something else to attach to. That way the tyrosine never makes melanin particles.

Nothing works better than HQ – it’s considered the gold standard for skin lightening. Here’s a quote from Dr. Rendon, associate clinical professor, University of Miami who says “other products haven’t proven that they really are as good as they say they are. In the few studies that actually compare them to hydroquinone, they never beat it.” Now, that doesn’t mean it works instantly – it can take several months of usage to reach maximum lightening efficacy.

What are the concerns about HQ?
There are some concerns about HQ, as you probably have heard. The reaction that’s responsible for it working so well also causes damage to the melanosomes and melanocytes which is one of the reasons HQ raises safety concerns. And animal and cell culture studies have shown that HQ can cause DNA damage which has raised concerns about cancer. Another concern:  In some people HQ causes a condition called Ochronosis (Oak-row-know-sis) which is a permanent bluish-black discoloration of the skin. This is rare and some dermatologists say it only occurs after prolonged use of high concentration hydroquinone.

So is HQ safe or not?
These studies that raised cancer concerns were based on oral or injected application and there have been no clinical studies or cases of skin cancer or any kind of internal malignancy related to topical HQ use. Therefore, the International Agency for Research on Cancer  (IARC) considers hydroquinone as “not classifiable” as to its carcinogenicity in humans. As far as the Ochronosis is concerned, this is one of reasons that regulatory bodies in other countries have banned HQ for over the counter use. It has has to be prescribed by a doctor which helps prevent the kind of long term abuse that can lead to that permanent discoloration. In the US The Food and Drug Administration (FDA) has even proposed banning over-the counter skin bleaching agents containing hydroquinone but as of right now it’s still available.

(Very important point – it’s a myth that’s it’s “banned” in other countries, it’s really just restricted to prescription use. Europe and Asia currently allow hydroquinone at 2-5% concentration by prescription. The drug is valued worldwide but is regulated to protect against misuse and bad formulations.)

There are quite a few other ingredients which have skin lightening properties but based on everything we could find, nothing works as well as HQ and some of the ingredients that work pretty well have their own issues. While it’s generally recognized that HQ is the gold standard, there are not a lot of studies directly comparing all these other agents to each other. So it’s difficult to rank them. But we’ll give you a quick run down.


This is a derivative of HQ which According to Dr. Draelos, this outperforms OTC alternatives and is a prescription alternative to hydroquinone. Of course, as you’ll see with almost all these agents it has side effects as well which include erythema, burning, pruritus, desquamation, skin irritation.

Azelaic acid

It’s a dicarboxylic acid which occurs natural in wheat, rye, and barley. inhibits DNA synthesis in melanocytes and has a modest antityrosinase effect. According to some sources, it works better than 2% hydroquinone and about as good as 4%. The interesting thing is that its apparently safe to use during pregnancy. Side effects of itching, mild redness, scaling, and burning but overall this is a good contender. It’s also prescription. Kojic acid This is a fungal metabolite and also a famous cop show from the 70s. It works by inhibiting the production of free tyrosinase. Could not find any data directly comparing it to other agents but one source considers it to be be the most effective skin-lightening agent behind hydroquinone. We do know that it can cause greater irritation, it is highly sensitizing and may be mutagenic. For this reason, it is banned in Japan, just like over-the-counter (OTC) hydroquinone.

Alpha arbutin

Arbutin is chemically related to hydroquinone and was originally obtained from the bearberry plant. Like HA it decreases melanin biosynthesis through the inhibition of tyrosinase activity.  It also inhibits melanosome maturation and is less cytotoxic to melanocytes than hydroquinone. However, several studies have shown that arbutin is less effective than kojic acid for hyperpigmentation. Deoxyarbutin is a synthesized topical derivative. Studies have shown that it has an enhanced sustained improvement, general skin lightening and a safety profile comparable to hydroquinone.

Vitamin C

A study compared 5% ascorbic acid and 4% hydroquinone in 16 female patients with melasma and found 62.5% and 93% improvement respectively


It works by interfering with the interaction between keratinocytes and melanocytes, thereby inhibiting melanogenesis. We’ve talked about this in our anti-aging show and it does work but not much data comparing it to other options.

Licorice extract

Licorice extract improves hyperpigmentation by dispersing the melanin, inhibition of melanin biosynthesis and inhibition of cyclooxygenase activity thereby decreasing free radical production. Glabridin, a polyphenolic flavonoid is the main component of licorice extract. Studies have shown that glabridin prevents Ultraviolet B (UVB) induced pigmentation and exerts anti-inflammatory effects by inhibiting superoxide anion and cyclooxygenase activity. However, more studies are needed to prove its de-pigmenting action.


Works three ways: dispersion of keratinocyte pigment granules, interference with pigment transfer, and acceleration of epidermal turnover Something like 68% improvement (although you can’t really compare numbers across studies.) Side effects: erythema, peeling, and possible post inflammatory hyper pigmentation. Can help with Melasma which is in the dermis. Works very slowly. Takes 24 weeks or more at 0.1% Need a prescription. One paper we found listed something links an additional 16 other ingredients that have some data but not enough to fully validate them.

Undecylenoyl phenylalanine (Update 3/20015)

We just became aware of another ingredient Undecylenoyl phenylalanine. We don’t know much about this yet but here’s a quote from the Cosmetic Cop that provides a couple of helpful references:

“Although this ingredient’s research pales in comparison to what’s known about hydroquinone and many forms of vitamin C, it is a promising ingredient that is worth considering in products meant to lighten brown spots and help even out skin tone (Sources: Journal of Cosmetic Dermatology, September 2011, pages 189–196 and December 2009, pages 260–266; and Clinical Experiments in Dermatology, July 2010, pages 476–476).”

Skin lightening vs brightening vs “imperfection correctors”

True skin lightening products are drugs and have to be labeled with very specific language. If you are selling an HQ product it has to bel labeled as a “skin lightener” or a “skin bleach.” If you are selling a cosmetic that uses any of the other ingredients we talked about you CAN’T call it a skin lightener or a bleach which is why you see products called “brighteners” imperfection correctors” and so forth. These are marketing terms that are NOT regulated by law which explains why they are so confusing. Our recommendation is not to pay too much attention to the name but rather look for the active ingredients.

The Beauty Brains bottom line

Check with your doctor but based on the evidence we’ve seen, for treatment of isolated areas of hyper-pigmentation (a couple of dark spots here and there), short term use of hydroquinone followed by the use of sun protection is most effective. Under those use conditions they’re don’t appear to be any serious health issues. We do not recommend it for long term use over larger areas of your body (e.g, trying to lighten overall skin tone).





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