Skincare 101: What you should know about peels and acids

So most of the skincare stuff I’ve blogged about so far consist of masks and makeup removers. I gave a little review of DDG extra strength peel pad here but we haven’t really discussed peels. We really should. Peels and acids are chemical exfoliators. They can lighten your dark spots, even your skintone, makes your skin smoother and younger and clearer. While you don’t need to go to a dermatologist office in order to get some good peels, you can’t just grab a random one off the shelf either since the wrong usage/product can damage your skin. Here’s a little introduction, or review for those who are skincare savvy, about acids and peels.


First, let’s look at the acids most commonly used in scrubs and peels from the smallest molecule to the largest (smaller molecule penetrates the skin and works on a deeper level while larger ones work on the surface):

  • Glycolic Acid – derived from sugar and a popular ingredient in higher end and anti-aging products. It penetrates deeper into the skin and produces more dramatic result, but can potentially irritate.
  • Lactic Acid – derived from dairy and fermented products. It draws moisture to the skin as it removes dead cell, so it’s a hydrating acid.
  • Fruit Acids – consist of citric (lemon, grapefruit etc) and malic (apple) etc works on the uppermost layer of the skin and often combined with glycolic and lactic for faster results.
  • Salicylic Acid – also known as beta hydroxy acid (BHA), most often used to unclog oily pores and treat acne. It is oil soluble, therefore effective for oily skin in unclogging pores and treating acne, while AHA (the other ones above) are water soluble, so they are best for sun damage, dark spots and smoothing the skin texture.
  • Enzyme – it is not an acid, but it is often combined with acid in peels/masks and serve the same purpose in that it exfoliate dead skin cells and help with pigmentation, blemish, fine lines etc. The more common types are pumpkin, apple and papaya (papain). They are usually a bit more gentle and subtle than acid peels, but there’s less of a chance for irritation/sun sensitivity. In addition to the exfoliating properties, enzyme encourage skin healing and renewal. If your skin is feeling sluggish, like the flaky patches are never ready to shed etc. Enzyme mask/peel will help jump-start your skin. I find it particularly useful during change of the season, in the fall, otherwise I just exfoliate normally.

Ps. The effectiveness of a product is not always determined by the percentage/strength of one acid, a mixture/combination of different acid is more effective since it targets different areas, or work on the skin from different perspective, at the same time.

Fancy terms for exfoliators

You might see the term scrub, microdermabrasion and peels thrown around a lot when describing products that exfoliates. What’s the difference? scrub and microdermabrasion are usually used to describe products that exfoliate physically with some granule/particles, altho they may have contain some type of acid in the ingredients. Scrub usually have larger particles while microdermabrasion is more fine (some derm count Clarasonic as microdermabrasion since the brush provides very fine exfoliation, which is also why you should not use a scrub with Clarasonic). Peels are usually chemical exfoliator using acids, while some are paired with a physical exfoliator like scrub or the texture pad that is used to apply the solution.

Acid in other products

Scrubs: Scrubs work on a surface level while acids exfoliate more evenly and more finely/on a micro-level. Sensitive skins are more suited to gentle acid/peels since granules of a scrub might irritate it, and very dry skins might prefer an oil scrub or those with moisturizing ingredients rather than acids. However, a scrub with acids as ingredient combines the best of both physical and chemical exfoliators, where the granule helps to slough off the flaky/dead skin on the surface so the chemical exfoliator/acid can penetrate deeper into the skin and be more effective. You just gotta pick the right acid. Salicylic acid is the most common acid used in drugstore skincare for acne cleanser/scrubs and it tends to dry my skin out without doing anything else. Glycolic acid does give my skin a nice glow but can be a bit too intense combined with a scrub since I’m heavy handed. My favorite is Dr. Brandt Microdermabrasion which contains very very fine granules and uses lactic acid, which is gentle and hydrating.

Cleansers: if you have acne-prone, then a salicylic acid cleanser might be worth it since it targets oily clogged pores so even if it’s only on your skin for a minute it still will have an effect. However, if that is not your skin type and for other types of acids, the ingredients are probably not worth the price and it’s better to go for a gentle cleanser while looking for those same acids in a treatment product (peel, serum/moisturizer etc).

Moisturizer/lotions: some facial moisturizer or body lotion have AHA and/or BHA in them. They unclog pores and dissolve dry skin, so if you get acne or have bumpy skin on your face or body, this might be worth looking into. If you have very sensitive skin and gets irritated from all scrubs/peels but still want a little exfoliation, this might also be a good choice. However, it usually is for oily/combo skin rather than drier skin since most moisturizer with AHA/BHA are not very rich/creamy/hydrating.

How do you know you got it right?

Your skin doesn’t have to peel for it to work. While retinoids repair skin by kick-starting inflammation, acids dissolve the upper layer of cells to trigger repair. Because the shedding is on a finer/micro level, you may not see peeling even if it is working. Some people might experience a bit of redness or peeling, but you do NOT need to have red/irritated/peeling skin for the acids/peels to work. If your skin feel raw/irritated, then the peel you tried might be too strong. If your skin feels tender/very sensitive for days afterward, decrease the usage (from daily to every other day, or from twice a week to once a week).

You might feel a slight tingle or stinging, but NO burning/painful feeling. The percentage of acid is not everything, the free-acid in it is important, too. Too much acid then your skin gets irritated/damaged, but too little then it won’t do anything. The ideal pH is between 3 and 4, which no product will tell you ever. If the acid is penetrating, then you should see/feel something, a slight tingle or mild stinging while applying the product, or instant gratification such as leaving your skin looking refreshed.

Be gentle and go slow. If you overdo the exfoliation with the peels, scrubs, brushes etc, it may result in dark spots/pigmentation for some skin type (called post-inflammatory hyperpigmentation). It is much easier to amp up the usage if you are not seeing results than to fix red/damaged/irritated skin from too much acid/peels. While sometimes you can tell the irritation immediately, some may take up to a week to show up. Always follow the gentlest instruction first, which is usually once a week, and ramp up to daily (or every other day) use if needed. Even if a peel specifies daily use, the most often/frequent I’m willing to exfoliate is once every two days. Basically try to pair with a gentle cleanser and make sure your skin is hydrated. Be diligent about wearing sunblock during the day and, depending on the intensity of your peel, avoid retinol.

If you messed up. Is your skin red and blotchy even hours after the peel? does it burn/sting every time you touch it? Stop. Stop stop stop. Stop using that peel, and make sure the rest of the skincare products you are using are as gentle as possible. That means a gentle cleanser rather than one with acid, and maybe a plain moisturizer instead of one with potent active ingredients for anti-aging or brightening. Go back to the basics and keep your skin hydrated/moisturized, that’s all you can do until your skin gets back to normal (and avoid the sun or fragranced/possibly irritating makeup). It might get flaky before getting back to normal, but be patient and be gentle. Then use a gentler peel or cut back the usage when you are ready to get back into it.

NOTE: Acids and peels won’t work on deep wrinkles or firm/lift sagging skin. I did not cover the acids/peels used by dermatologists, which are more heavy duty, so if you want a more detailed/clinical view that also includes trichloroacetic acid and phenol, check out Paula’s Choice. If you want to know more about what to expect from a peel with derm, this is a nice Q&A. Pregnant women should avoid chemical peels altogether. Dark skinned ladies need to be especially careful to not overdo it, maybe using only one acid product at a time. Some more intense peels, such as those with 30% or more glycol or TCA, might actually cause MORE hyperpigmentation and look blotchy on dark skin.


  • Acid Trip, article from Allure Feburary 2014 issue.
  • General peel info:
  • Detailed breakdown of types of acids:
  • Enzyme peels:
  • Personal Experiences with too many peels, lol.

4 thoughts on “Skincare 101: What you should know about peels and acids

  1. You forgot about mandelic acid, azelaic acid, TCA peels, citric acid, malic acid & kojic acid amongst others which are being used more & more frequently, even in over-the-counter skin care products.

    Mandelic acid is very effective for those prone to breakouts, who have oily skin & who usually have issues with blocked pores. It penetrates more deeply than glycolic acids, lactic acid & salicylic acid. It’s incredibly effective but seems to be even more effective when used in formulations in conjunction with malic acid.

    Malic acid alone is also very good for those with breakouts and can be used in conjunction with citric acid as well. I personally love what malic acid does for the skin just overnight. Great stuff.

    Salicylic acid is great in the right formulation for those suffering from acne & generally congested skin. But again, it depends on the formulation it’s in. I’ve seen far too many rubbish products being pimped as ‘peels’ that are nothing more than salicylic acid, propylene glycol & alcohol. Pure junk. There are some good brands out there with salicylic acid in their formulations, however. CosRX – a Korean brand – has a great 2 step system with an emulsion & a product strangely called a ‘skin returning a-sol’, A-SOL standing for ‘acne solution’, I believe. They’re quality products that are very effective very quickly, and which don’t irritate the skin at all. Korean brands are far ahead of the rest of the world, for sure. They appear to have a very good handle on combining nature with scientific/technological advances, unlike North American skin care brands. FYI willow bark extract – which is where salicylic acid originated from way back when – is very easy to find online & can be added to quality skin care products a person might have at home. It too is very effective, as well as gentle & free of unnecessary added garbage such as alcohol & propylene glycol.

    Lactic acid is great for dryer skin types but also works on other types equally well. Lactic acid seems to be less drying/irritating to dryer skin in my experience. It’s also added to shampoos & other personal care products, and is found naturally/added to foods. Lactic acid, along with beneficial bacteria or ‘probiotics’, is also found in yogurt. Yogurt is a beautiful ingredient to add to your own DIY masks at home. It leaves the skin smooth, brightened & very clean. Even without pre-cleansing.

    TCA peels I’ve found to be the harshest of the bunch & personally wouldn’t recommend them or use them. The after-effects are some of the gorriest I’ve seen to date, although that is part of the process of TCA peels. That being said, a lot of people love them & swear by them. Plan time off from anything important like a wedding, or even work, if you’re doing a TCA peel as you really DO peel after these, in sheets & chunks of skin. The higher the percentage of the TCA peel, the more actual peeling you will do over a period of days. The process ain’t pretty 🙂 They do have a noticeable effect on the skin, for sure, but I haven’t yet seen any studies which vouch for the safety of these peels. The possible negative effects which could show up later in life – on the skin or elsewhere in the body – are something to seriously consider. Most frightening of all, there are many foolish people buying very strong TCA peels from eBay & Amazon, doing a TCA peel at home for the very first time. Done incorrectly, TCA peels can cause permanent scarring. Definitely not a DIY project for the ignorant.

    Kojic acid seems to be primarily used for skin lightening, freckle fading etc, although some concerns have come up about this particular acid as it builds up its levels in the bloodstream with prolonged use, according to the EU & their studies. I trust the EU & their data as far more credible than the FDA & Health Canada as their standards are much higher than North America’s. Kojic acid can also supposedly be a ‘sensitizer’, which I consider to be nonsense as pretty much anything – especially acids – can be considered a so-called ‘sensitizer’. The fact that significant levels can be found in the blood with habitual use concerns me far more as there doesn’t seem to be much definitive info regarding its long term effects in the body. It is preferable over hydroquinone, however, when it comes to the many hazards associated with that particular skin lightener. Unfortunately, hydroquinone is still widely used in many countries where societies view white skin as supposedly ‘clean’ & a sign of prosperity, as opposed to dark skin being viewed as supposedly ‘dirty’ & a sign of coming from a lower societal class. Pretty messed up…..

    Azelaic acid is used for those with rosacea, acne type rosacea, acne & those prone to skin inflammation. It can be used by pretty much anybody with any skin type as it is claimed to be ‘soothing’ to irritated skin.

    Citric acid seems to work really well for lightening minor discolourations such as sun-spots & acne scars, even for whitening yellowed fingernails. I wouldn’t use copper ferment products after citric acid, however. See below regarding copper ferment type products.

    One other point of interest regarding peels, whichever a person chooses, is that serums/treatments with a higher concentration of copper ferment work amazingly well on the skin after a peel/deep exfoliation of any type, especially when the acid treatment is done at night, followed immediately by a copper-type treatment product, then a high quality moisturizing oil (yes, even for oily, breakout prone skin), then going to bed. I’ve seen the overnight effects myself, which are quite amazing. By morning, the skin is significantly smoother, pores appear noticeably smaller & overall skin tone is more even. In addition, it reduces breakout inflammation quite well following an acid treatment. However, as I understand it, it’s not a good idea to use copper ferment & vitamin c type skin care products at the same time. Choose one or the other in rotation.

    I hope this further information regarding peels & acids helps anybody who is considering messing with this stuff at home. Yes, acids can be very effective for many skin care issues, but don’t just believe everything you read out there or hear other people recommending. Do your own research, dig for studies, success AND horror stories (learn from others’ bone-headed mistakes, and start slow. Especially if you’re new to acids. In addition, don’t be afraid of trying your own formulations at home, but only do so after doing research. You could save yourself a lot of unnecessary problems, and maybe even scars.

    1. Woah! Thanks for the amazing amount of information and details! I wrote the blog post intending it to be just a brief reference when shopping for peels and only recently start branching out into other acids like Kojic. And that is a very interest point about copper. I am vaguely aware that gold, silver and copper are suppose to be good for your skin in some ways but have not delved into it to find more info yet, and you’ve piqued my interest again. =D

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