Tag Archive: bha

A Dermatologist’s Guide on Polyhydroxy Acid (PHA)

June 13, 2019

PHA Polyhydroxy Acid Needed

Is PHA (polyhydroxy acid) suitable for all skin types? How does it compare to AHAs aacnnd BHAs?

Polyhydroxy acids encompass gluconolactone and lactobionic acids. It has been reported in medical papers as early as 2004 to be effective and better tolerated by sensitive, aging skin.

PHAs works similarly to AHAs by causing the dead skin cells (keratinocytes) to shed at a higher rate, causing reduction in skin irregularities such as uneven pigmentation and texture. In addition, they fulfill the same function of allowing cosmeceutical ingredients such as hyaluronic acid and vitamin C serums to penetrate deeper into the skin.

Is there a possibility of suffering from a chemical burn using skincare products that contain PHA?

PHAs are not as commonly used as AHAs and BHAs, especially as chemical peels in dermatologists’ office setting mainly because the depth of penetration and effectiveness may be less. However, in skincare, the medical literature seems to report that it is a much gentler and moisturizing type of chemical exfoliant than the other acids present in skincare, which translates into a much lower risk of skin irritation. In fact, PHAs are large molecules which function as humectants meaning that they trap water under the skin, prevent trans-epidermal water loss and have moisturizing properties.

Is there one form of PHA that’s stronger than the others? eg. Lactobionic acid vs Gluconolactone  

Clinical studies to date have grouped the use of gluconolactone and lactobionic acids under PHAs which differ from glycolic acids in the fact that they have a larger molecular structure, penetrate the dermis less and hence is less irritating in addition to having humectant (moisture trapping) properties. I am unaware of any head-to-head study which show whether one form of PHA is stronger than the other.

When should I use PHA? Should I use it in the toner, serum, moisturiser, or cleanser step?

The use of PHAs in skincare has been well-reported to have good exfoliating effects but without the irritation that glycolic (AHA) or salicylic acids (BHA) have. However, I generally do not put in chemical exfoliants in skincare because there is always a risk of skin becoming sensitive after being exposed to it on a daily basis.

While there are some studies which have shown that compared to glycolic acids which are incorporated in several brands of skincare, those which incorporate PHA are much more suited for people with sensitive, eczema skin, I would not prescribe that for my patients with eczema and rosacea in the first place.

What should I be looking out for when I use PHAs?

I would say PHAs seem to be rather novel because it’s a term that hasn’t been used in the recent times but our knowledge of it has stemmed since the 1970s and clinical studies have been done with it since 2004. I think it’s important to prioritise, so the main concern really would be to ask yourself what your skin concern is. If it is anti-aging, then chemical exfoliation itself is not going to give you a miracle result. Chemical exfoliation can be achieved with glycolic acids, BHAs and in this case PHAs may have the same function but with reduced skin irritation. However, chemical peels alone do not satisfactorily target all skin aging concerns, which lasers in combination with a good cosmeceutical regimen can achieve. It is important to caution that while all anti-aging treatments are aimed at increasing collagen production in the skin, an accredited dermatologist still needs to access the individuals’ problems and side effects before recommending combination treatment.

PHAs should be used in conjunction with cosmeceutical ingredients such as vitamin C as well as phyto which are plant-derived antioxidants that have been proven to fight free radical damage which is the key process in anti-aging. Nevertheless, PHAs are a beneficial form of chemical exfoliation and should be placed in the same category as the use of AHAs and BHAs in chemical peels.

One more thing to add, the clinical results in terms of the depth of skin penetration are likely to be less with PHAs. For patients with other forms of skin concerns, for example acne, they may still find that glycolic acid is much more effective in reducing oil control. If their concern is a medical condition like eczema and rosacea, then certainly I would recommend not using any form of chemical exfoliant at all and rather get treated by a dermatologist.

© 2019 TWL Specialist Skin and Laser Centre. All rights reserved.

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Meet with Dr Teo Wan Lin, an accredited dermatologist at TWL Specialist Skin & Laser Centre, for a thorough consultation to determine the most suitable treatment for your skin.

To book an appointment with Dr Teo, call us at +65 6355 0522, or email appt@twlskin.com. Alternatively, you may fill up our contact form here.

A Dermatologist’s Guide to Exfoliation

January 20, 2019

Exfoliation, or the removal of dead skin cells from the outermost layer of the skin, is an important and necessary part of any skincare routine. However, if the word ‘exfoliation’ conjures up the action of scrubbing your face with harsh granules, you may be doing more harm to your skin than good.

So what is the right exfoliation technique for your skin?

Benefits of exfoliation

We shed dead skin cells naturally as new skin cells slowly travel up from the deepest skin layers to the surface. On average, this process takes about 27 days.  As we age, this cell turnover process slows down.

When we exfoliate, we remove the build-up of dead skin cells. Regular exfoliation can reveal younger, brighter skin with an even tone. 

Types of exfoliation

Exfoliation can happen in two forms: physical and chemical.

  • Physical exfoliation: Physical exfoliation relies on the rubbing of tiny granules or particles over the face to remove dead skin cells by physical force.

While this kind of exfoliation can leave you feeling refreshed, the technique can be too harsh for the skin, especially for individuals with acne-prone or sensitive skin. Physical exfoliation may even weaken the skin’s barrier function and leave your skin red or irritated.

For those of you without sensitive or acne-prone skin, physical exfoliation can still be an option. However, make sure to look out for exfoliating agents that are not too large.

  • Chemical exfoliation: Chemical exfoliation relies on fruit enzymes and gentle acids to slough off dead skin. This mechanism is much gentler than physical exfoliation and more suitable for acne-prone and sensitive skin types.

Types of acids

The two most well-known type of exfoliating acids is alpha hydroxy acids (AHA) and beta hydroxy acids (BHA).

AHAs: Alpha hydroxy acids work by causing skin cells to detach from the outermost layer of skin, making them easier to slough off. Once the dead skin cells are removed, new cells can rise to the surface.

Common AHAs used as chemical exfoliants are lactic, glycolic and mandelic acid.

Glycolic acid: Glycolic acid is the strongest AHA as it has the smallest AHA molecule. As such, it is able to penetrate deeper into the skin and can exfoliate at lower concentrations compared to other acids. However, if you are just beginning to try out chemical exfoliants, a different acid should be considered.

Lactic acid: Apart from exfoliating, lactic acid also moisturizes. Individuals with dry skin can consider lactic acid for this dual function.

Mandelic acid: With a larger molecular structure, mandelic acid is not able to penetrate deeply into the skin. This makes it a gentle AHA and safe to use, especially for people with sensitive skin.

BHAs: Beta hydroxyl acids (BHAs) differ from other AHAs as they are oil-soluble. This property allows them to penetrate deeper into our skin and pores.

BHAs exfoliate by softening the outermost layer of skin cells and dissolving unwanted skin debris. They also have anti-inflammatory and antibacterial properties, making them ideal for individuals with oily and acne-prone skin.

Chemical peels

Chemical peels are often done at a dermatologist’s office where the chemical agent used can be much more concentrated. Glycolic, lactic or salicylic acid is commonly used. A certified dermatologist is best able to identify the type of peel for your skin.

With regular use, these treatments exfoliate the surface skin and improve fine lines, wrinkles, skin discolouration and texture.

Chemical exfoliation at home

Most patients prefer to do chemical exfoliation on their own. However, this can cause skin sensitivity and redness for certain individuals over time without proper medical supervision.

As a result, Dr Teo Wan Lin, an accredited dermatologist at TWL Specialist Skin & Laser Centre, recommends using active ingredients such as stabilised vitamin C (sodium ascorbyl phosphate), hyaluronic acid, phyto plant extracts or LARECEA™ extract. These ingredients are proven to deliver health to your skin without the sensitivity that AHA or BHA might cause when used without medical supervision.

Over-exfoliation

The benefits of chemical exfoliation may make it tempting to use AHAs and BHAs often. However, too much exfoliation can disrupt your skin barrier and cause the skin to become red and inflamed.

If you are a beginner to AHA and BHA, start slow. If you do not have sensitive skin, exfoliate every other day. Those with sensitive skin should stick to exfoliating once a week. Discuss with your dermatologist how often you should get chemical peels.

© 2019 TWL Specialist Skin and Laser Centre. All rights reserved.

—–

Meet with Dr Teo Wan Lin, an accredited dermatologist at TWL Specialist Skin & Laser Centre, for a thorough consultation to determine the most suitable treatment for your skin.

To book an appointment with Dr Teo, call us at +65 6355 0522, or email appt@twlskin.com. Alternatively, you may fill up our contact form here.